CC-Nutrition

Tag: basketball

  • Parent Football Nutrition Guide: Fuelling Young Players Effectively

    Parent Football Nutrition Guide: Fuelling Young Players Effectively

    Youth football nutrition plays a key role in energy levels, recovery, focus, and consistency across the training week. Many young players are not underperforming because of fitness or talent, but because of inconsistent fuelling and hydration patterns across the day. This guide explains how parents can support practical, realistic nutrition habits that directly improve performance, recovery, and wellbeing.

    Why youth football nutrition matters

    Football is a high-intensity intermittent sport involving repeated sprints, rapid changes of direction, physical contact, and constant decision-making under fatigue. These actions rely heavily on muscle glycogen, the body’s stored form of carbohydrate. When glycogen levels drop, performance declines, particularly in repeated sprint ability and late-game intensity (Bangsbo et al., 2006; Burke et al., 2011). This often presents as players starting strongly but fading in the second half, reduced reaction speed, and slower decision-making under pressure.

    In children and adolescents, this is compounded by growth demands, meaning energy is also required for:

    • Muscle repair and adaptation
    • Bone growth
    • Hormonal development
    • Cognitive function

    (Gibson et al., 2011)

    1. Pre-training and pre-match nutrition (football pre match meal)

    The goal before football is to ensure sufficient carbohydrate availability to support high-intensity performance throughout the session or match (Burke et al., 2011). Think of this as “fuel loading” rather than just eating to stop hunger.

    2–3 hours before training or match (main meal)

    This meal should:

    • Top up carbohydrate stores (main fuel source)
    • Provide moderate protein for muscle support
    • Be low in fat and easy to digest

    Examples:

    • Pasta with chicken in tomato sauce
    • Rice with chicken or turkey
    • Wraps with chicken and light sauce + fruit
    • Cereal with milk, banana, and yoghurt
    • Toast with scrambled eggs and fruit juice

    Avoid meals that are too light (e.g. fruit or yogurt alone), as they do not provide enough energy for high-intensity performance.

    30–60 minutes before exercise (optional snack)

    Useful if there is a long gap since the last meal or the player feels hungry.

    Examples:

    • Banana
    • Cereal bar
    • Yogurt pouch
    • Toast with honey

    This helps maintain blood glucose availability early in exercise (Jeukendrup, 2014).

    2. Hydration for young footballers

    Even mild dehydration can reduce reaction time, concentration, and endurance performance (Thomas et al., 2016). Children are especially vulnerable because they often:

    • Forget to drink during school
    • Don’t recognise early thirst
    • Become distracted during play

    Practical approach:

    • Encourage regular drinking throughout the day
    • Use small, frequent sips during training
    • Rehydrate after sessions at home

    Simple check:

    • Pale yellow urine usually indicates good hydration status

    3. During training and matches

    For most youth football sessions under 90 minutes:

    • Water is sufficient
    • No structured fuelling is needed

    For tournaments or hot conditions:

    • Hydration becomes more important
    • Fluid loss can significantly impact later performance

    A common issue is performance drop-off in later games due to cumulative dehydration and reduced energy availability (Burke et al., 2011).

    4. Football recovery nutrition (post training nutrition)

    Recovery is where many young players lose performance consistency without realising it. After football, the body needs to:

    • Refill muscle glycogen
    • Repair muscle tissue
    • Restore fluid balance

    Recovery is most effective when nutrition is consumed within 1–2 hours post exercise (Burke et al., 2017).

    Best recovery approach: carbohydrate + protein

    Examples:

    • Chicken and rice
    • Tuna sandwich + fruit + yogurt
    • Milk smoothie with banana and oats
    • Eggs on toast + milk
    • Yogurt with granola and berries

    Poor recovery nutrition can lead to:

    • Increased fatigue
    • Reduced performance in next session
    • Slower weekly recovery cycle

    5. Daily youth athlete nutrition habits

    Consistency across the week is more important than match-day nutrition strategies (Desbrow et al., 2014).

    Key habits:

    • Eat breakfast every day
    • Avoid long gaps between meals
    • Include carbohydrates at most meals
    • Include protein for growth and repair
    • Eat fruit and vegetables daily
    • Maintain regular hydration

    Many young athletes under-fuel during school hours, which reduces evening training quality (Gibson et al., 2011).

    6. Travel nutrition for football matches

    Away games often disrupt normal eating routines, which can negatively affect performance (Burke et al., 2011).

    Common issues:

    • Missed meals before travel
    • Long gaps without food
    • Reliance on convenience snacks
    • Nervous appetite suppression

    Practical strategy:

    • Eat a carbohydrate-based meal before leaving home
    • Bring familiar, easy-to-eat foods

    Examples:

    • Sandwiches
    • Fruit
    • Cereal bars
    • Yogurts
    • Water

    Avoid relying on unfamiliar venue food options.

    7. Common youth football nutrition mistakes

    • Under-fuelling disguised as “healthy eating” (fruit or yogurt alone is not enough energy)
    • Skipping recovery meals after training (reduces glycogen restoration)
    • Hydration only on match days rather than daily
    • Over-reliance on supplements instead of food-first nutrition (Thomas et al., 2016)

    8. Warning signs of poor football nutrition

    Look for:

    • Early fatigue in training
    • Drop-off in second-half performance
    • Poor concentration late in sessions
    • Slow recovery between training days
    • Frequent minor illness
    • Heavy legs during warm-ups

    These are often nutrition-related rather than fitness-related (Gibson et al., 2011).

    9. Energy availability and development

    Energy availability is the energy left after exercise that supports growth and normal body function.

    Low energy availability can affect:

    • Growth and development
    • Bone health
    • Recovery capacity
    • Injury risk
    • Training adaptation

    (Gibson et al., 2011; Thomas et al., 2016)

    This usually develops gradually through small daily deficits rather than intentional restriction.

    Conclusion

    Effective youth football nutrition is built on:

    • Adequate fuelling before activity (Burke et al., 2011)
    • Consistent hydration habits (Thomas et al., 2016)
    • Structured recovery nutrition (Burke et al., 2017)

    Small improvements in these areas can significantly improve performance, recovery, and enjoyment of football.

    Final note for parents

    Every young footballer is different, and nutrition needs vary based on training load, growth stage, and individual response. If you are unsure whether your child is fuelling correctly for football, or you would like personalised support tailored to their schedule and development, you can get in touch for expert nutrition guidance.

    Contact me

  • Creatine Supplementation in Male and Female Athletes: An Evidence-Based Review of Mechanisms, Performance, Recovery and Sex-Specific Responses

    Creatine Supplementation in Male and Female Athletes: An Evidence-Based Review of Mechanisms, Performance, Recovery and Sex-Specific Responses

    Introduction

    Creatine monohydrate is one of the most extensively researched and scientifically supported ergogenic aids in sport and exercise science. Contemporary consensus statements confirm that creatine is effective for improving high-intensity exercise performance, increasing lean mass and enhancing training adaptations across a wide range of populations (Kreider et al., 2022; Antonio et al., 2021). Unlike many supplements in sport, creatine has a consistently strong evidence base supported by systematic reviews and meta-analyses, particularly when combined with resistance training (Chilibeck et al., 2017; Candow et al., 2019; Forbes et al., 2021). Although the physiological mechanisms are similar between males and females, emerging evidence suggests sex-specific differences in creatine metabolism, baseline muscle creatine stores and hormonal regulation may influence responsiveness and practical application (Smith-Ryan et al., 2021; Delpino et al., 2022).

    Physiological Role and Mechanisms of Action

    Creatine functions primarily within the phosphagen energy system, supporting rapid ATP regeneration during high-intensity exercise. During maximal effort, ATP is rapidly depleted and resynthesised via phosphocreatine (PCr), catalysed by creatine kinase. Contemporary evidence confirms that creatine supplementation increases intramuscular total creatine and phosphocreatine stores, enhancing ATP resynthesis during repeated high-intensity efforts (Kreider et al., 2022; Forbes et al., 2021). Key physiological effects include increased phosphocreatine availability, enhanced sprint and resistance performance, improved training volume tolerance, intracellular hydration and upregulation of anabolic signalling pathways associated with hypertrophy (Kreider et al., 2022; Antonio et al., 2021). Cell swelling is considered an anabolic stimulus contributing to protein synthesis and reduced protein breakdown (Forbes et al., 2021).

    Creatine and Performance in Males

    Meta-analytical evidence consistently demonstrates creatine improves maximal strength, lean body mass, training volume and muscular hypertrophy when combined with resistance training (Chilibeck et al., 2017; Candow et al., 2019). A meta-analysis reported significantly greater increases in lean mass with creatine supplementation alongside resistance training compared with training alone (Chilibeck et al., 2017). More recent evidence confirms increases in lean body mass of approximately ~1 kg in trained and untrained populations (Delpino et al., 2022). Creatine also improves repeated sprint ability, peak power output and anaerobic performance capacity, making it highly relevant to team sports such as football, rugby and hockey (Kreider et al., 2022; Antonio et al., 2021).

    Creatine and Performance in Females

    Although historically underrepresented in research, recent systematic reviews demonstrate that females benefit from creatine supplementation in strength, high-intensity performance and lean mass adaptations (Smith-Ryan et al., 2021; Delpino et al., 2022). Females typically have lower baseline intramuscular creatine stores and dietary intake, which may influence responsiveness (Smith-Ryan et al., 2021). While absolute gains in lean mass are often smaller than in males, relative improvements are comparable when adjusted for baseline differences (Delpino et al., 2022). Evidence suggests creatine may be particularly relevant in female athletes due to hormonal influences on energy metabolism and creatine kinase activity across the menstrual cycle (Smith-Ryan et al., 2021).

    Creatine and the Menstrual Cycle

    Oestrogen and progesterone fluctuations influence substrate utilisation, neuromuscular performance, thermoregulation and fatigue perception. These hormonal changes may also influence creatine kinase activity and energy metabolism (Smith-Ryan et al., 2021). Although phase-specific intervention studies remain limited, creatine’s role in ATP resynthesis suggests potential benefits during phases of increased fatigue or reduced energy availability.

    Creatine, Recovery and Training Adaptation

    Creatine supplementation may enhance recovery between training sessions and improve tolerance to high training loads. Evidence suggests improvements in training volume capacity, reductions in muscle damage markers in some contexts and enhanced glycogen resynthesis when combined with carbohydrate intake (Antonio et al., 2021; Kreider et al., 2022). These effects are most pronounced when creatine is combined with structured resistance or high-intensity training programmes (Candow et al., 2019).

    Creatine and Cognitive Function

    Creatine plays a role in brain energy metabolism, and supplementation may improve working memory, processing speed and cognitive resilience under stress or sleep deprivation (Antonio et al., 2021; Kreider et al., 2022). These effects are most evident in conditions of metabolic stress, making creatine relevant for athletes experiencing travel, congestion, sleep disruption or high cognitive load. This may also be relevant for female athletes experiencing cyclical fatigue or hormonal fluctuations (Smith-Ryan et al., 2021).

    Creatine Across the Female Lifespan

    In adolescence, creatine supports strength and power development alongside training. During reproductive years, it supports high-intensity performance and recovery. In perimenopause and menopause, creatine combined with resistance training improves lean mass, strength and functional performance (Candow et al., 2019; Delpino et al., 2022). Bone health outcomes remain inconclusive, but functional improvements are consistently reported.

    Safety and Long-Term Use

    Consensus statements confirm creatine monohydrate is safe when used at recommended doses in healthy individuals (Kreider et al., 2022). Evidence does not support adverse effects on kidney function, liver function, hydration status or cramping risk (Antonio et al., 2021; Kreider et al., 2022). Long-term studies support its safety in both male and female populations.

    Practical Application

    Loading phase (optional): 20 g/day split into 4 doses for 5–7 days. Maintenance: 3–5 g/day. Alternatively, 3–5 g/day without loading achieves full saturation over ~3–4 weeks. Timing is not critical; total daily intake is the key factor (Antonio et al., 2021). Creatine monohydrate remains the gold standard due to its efficacy, safety, cost-effectiveness and evidence base (Kreider et al., 2022).

    Conclusion

    Creatine monohydrate is one of the most effective and well-supported supplements in sport science. Evidence demonstrates consistent benefits for strength, lean mass, high-intensity performance, recovery and cognition in both males and females. While males show greater absolute gains in lean mass, this is largely due to baseline physiological differences rather than differences in responsiveness. In females, creatine may have additional relevance due to hormonal fluctuations and lower baseline creatine stores. Overall, creatine should be considered a foundational evidence-based supplement for athletes across sexes and performance levels.

    References

    Antonio, J. et al. (2021) Journal of the International Society of Sports Nutrition, 18, pp.1–17.
    Candow, D.G. et al. (2019) Journal of Clinical Medicine, 8, 488.
    Chilibeck, P.D. et al. (2017) Open Access Journal of Sports Medicine, 8, pp.213–226.
    Delpino, F.M. et al. (2022) Nutrition, 103–104, 111791.
    Forbes, S.C. et al. (2021) Nutrients, 13(6), 1915.
    Kreider, R.B. et al. (2022) Journal of the International Society of Sports Nutrition, 19(1), pp.1–46.
    Smith-Ryan, A.E. et al. (2021) Nutrients, 13(3), 877.

  • Bone Health in Athletes: The Role of Energy Availability, Training Load and Stress Fracture Risk

    Bone Health in Athletes: The Role of Energy Availability, Training Load and Stress Fracture Risk

    Introduction

    Bone is a dynamic tissue that responds continuously to mechanical and metabolic stimuli. In athletic populations, bone health is determined by the interaction between mechanical loading, endocrine function, and energy availability rather than isolated nutrient intake alone (Turner, 1998; Tenforde and Fredericson, 2011).

    Although sports participation is generally associated with higher bone mineral density (BMD), certain training environments particularly those characterised by low energy availability are associated with impaired bone turnover and increased risk of stress injury (Mountjoy et al., 2018; Logue et al., 2020). This makes bone health a critical but often under-monitored determinant of long-term athletic performance and injury resilience.

    Bone Remodelling and Mechanotransduction in Sport

    Bone adapts to mechanical loading via remodelling, a process regulated by osteoblast and osteoclast activity. According to mechanostat theory, bone tissue responds to strain magnitude, rate, and frequency, increasing its structural strength when subjected to sufficient mechanical stress (Turner, 1998).

    High-impact, multidirectional loading sports stimulate osteogenesis more effectively than low-impact endurance activities. Evidence consistently shows higher BMD in athletes participating in sports involving jumping, sprinting, and rapid changes of direction compared with cycling or swimming (Tenforde and Fredericson, 2011).

    However, bone adaptation is not solely dependent on mechanical stimulus. Energy availability and endocrine function significantly modulate the remodelling response, with low energy availability attenuating bone formation despite mechanical loading exposure (Ihle and Loucks, 2004).

    Energy Availability as a Central Regulator of Bone Health

    Energy availability (EA), defined as dietary energy intake minus exercise energy expenditure relative to fat-free mass, is a primary determinant of physiological function in athletes (Loucks et al., 2011).

    Low energy availability impairs bone health through multiple mechanisms including suppression of bone formation markers such as osteocalcin and procollagen type 1 N-terminal propeptide (P1NP), alongside increased bone resorption markers such as C-terminal telopeptide (CTX) (Ihle and Loucks, 2004; Logue et al., 2020).

    Endocrine disruption is also central to this process. Low EA reduces insulin-like growth factor-1 (IGF-1), leptin, oestrogen, and testosterone, all of which are essential regulators of bone metabolism (Mountjoy et al., 2018). These hormonal changes shift bone turnover towards net resorption and impair recovery from microdamage accumulation.

    Stress Fractures and Bone Stress Injuries

    Bone stress injuries represent a continuum from periosteal oedema to cortical fracture and occur when repetitive submaximal loading exceeds the bone’s capacity for remodelling and repair (Warden et al., 2014).

    Key risk factors consistently identified in peer-reviewed literature include low energy availability, rapid increases in training load, prior stress fracture history, hormonal disturbances, and low bone mineral density (Mountjoy et al., 2018; Tenforde et al., 2015).

    Athletes with low energy availability exhibit significantly increased incidence of stress fractures due to impaired bone formation and delayed microdamage repair processes (Logue et al., 2020).

    Hormonal Regulation of Bone Metabolism in Athletes

    Bone remodelling is tightly regulated by endocrine signalling. Oestrogen and testosterone are critical for maintaining bone formation and inhibiting resorption (Mountjoy et al., 2018).

    In low energy availability states, oestrogen concentrations may decrease in female athletes, particularly in cases of functional hypothalamic amenorrhoea, while testosterone may also decline in male athletes. Insulin-like growth factor-1 (IGF-1) is suppressed, reducing osteoblastic activity, while cortisol may increase, promoting catabolic effects on bone tissue (Mountjoy et al., 2018).

    These endocrine changes collectively shift bone metabolism towards increased resorption and reduced formation.

    Mechanical Loading: Protective and Dose-Dependent Effects

    Mechanical loading remains one of the most potent stimuli for bone formation. High-impact loading generates strain-induced deformation and fluid flow within the bone matrix, triggering osteogenic responses (Turner, 1998).

    High-impact sports consistently demonstrate greater bone mineral density compared with low-impact endurance sports (Tenforde and Fredericson, 2011). Furthermore, plyometric and resistance training enhance site-specific bone strength adaptations (Tenforde et al., 2015).

    However, excessive repetitive loading without adequate recovery or energy availability results in microdamage accumulation and increased risk of bone stress injury (Warden et al., 2014).

    Nutrition and Bone Health: Beyond Calcium

    Energy availability is the primary nutritional determinant of bone health in athletes. Low energy availability suppresses bone formation even when calcium and vitamin D intake are adequate (Loucks et al., 2011; Mountjoy et al., 2018).

    Calcium plays a key role in bone mineralisation, but its effectiveness is dependent on hormonal status and energy balance. Vitamin D is essential for calcium absorption and bone metabolism, with deficiency associated with increased fracture risk in athletes (Close et al., 2013).

    Protein intake supports bone matrix formation and collagen synthesis. Evidence indicates that higher protein intakes do not negatively impact bone health when calcium intake is sufficient and may enhance IGF-1-mediated anabolic signalling (Shams-White et al., 2017).

    RED-S and Bone Health

    Relative Energy Deficiency in Sport (RED-S) describes impaired physiological function resulting from low energy availability. Bone health is one of the most significantly affected systems (Mountjoy et al., 2018).

    RED-S is associated with reduced bone formation markers, increased bone resorption, impaired attainment of peak bone mass, and increased stress fracture risk. Persistent low energy availability during key developmental periods may result in long-term deficits in bone mineral density (Mountjoy et al., 2018).

    Integration of Training Load and Energy Availability

    Bone adaptation is dependent on the interaction between mechanical loading and energy availability. Mechanical loading is only osteogenic when sufficient energy is available to support remodelling processes.

    When energy availability is low, the osteogenic response to loading is blunted, bone resorption exceeds formation, and adaptation to training is impaired. This explains the high incidence of bone stress injuries in athletes experiencing high training loads without adequate fuelling (Logue et al., 2020; Warden et al., 2014).

    Practical Implications for Athlete Management

    Optimising bone health in athletes requires a multi-factorial approach that includes maintaining adequate energy availability, structured mechanical loading, and appropriate nutritional support.

    Early identification of RED-S risk factors such as menstrual dysfunction, recurrent stress injury, fatigue, and rapid training load increases is essential for prevention (Mountjoy et al., 2018).

    Conclusion

    Bone health in athletes is governed primarily by the interaction between energy availability, endocrine function, and mechanical loading rather than isolated nutrient intake. Low energy availability is the most significant modifiable risk factor for impaired bone metabolism and stress injury development. Maintaining adequate energy availability alongside structured loading strategies is essential for optimal skeletal adaptation and injury prevention.

    References

    Close, G.L., Leckey, J., Patterson, M., et al. (2013) ‘Vitamin D and skeletal muscle strength in athletes’, Scandinavian Journal of Medicine & Science in Sports.

    Ihle, R. and Loucks, A.B. (2004) ‘Dose-response relationships between energy availability and bone turnover’, Journal of Bone and Mineral Research.

    Logue, D.M., Madigan, S.M., Melin, A., et al. (2020) ‘Low energy availability in athletes’, Sports Medicine.

    Loucks, A.B., Kiens, B. and Wright, H.H. (2011) ‘Energy availability in athletes’, Journal of Sports Sciences.

    Mountjoy, M., Sundgot-Borgen, J., Burke, L., et al. (2018) ‘IOC consensus statement on RED-S’, British Journal of Sports Medicine.

    Shams-White, M.M., Chung, M., et al. (2017) ‘Protein intake and bone health’, American Journal of Clinical Nutrition.

    Tenforde, A.S. and Fredericson, M. (2011) ‘Influence of sports participation on bone health’, Sports Health.

    Tenforde, A.S., et al. (2015) ‘Impact activity and bone density’, PM&R.

    Turner, C.H. (1998) ‘Three rules for bone adaptation’, Bone.

    Warden, S.J., Davis, I.S. and Fredericson, M. (2014) ‘Stress fracture biomechanics’, British Journal of Sports Medicine

  • Continuous Glucose Monitoring in Healthy Individuals: Evidence, Interpretation, and Practical Value Beyond Clinical Use

    Continuous Glucose Monitoring in Healthy Individuals: Evidence, Interpretation, and Practical Value Beyond Clinical Use

    Introduction

    Continuous glucose monitoring (CGM) systems are well established in diabetes care, where strong evidence demonstrates improvements in glycaemic variability, time in range, and hypoglycaemia prevention in both type 1 and insulin-treated type 2 diabetes populations (Battelino et al., 2019; Beck et al., 2017). In recent years, CGMs have increasingly been adopted by individuals without diabetes for purposes such as dietary optimisation, metabolic health tracking, and performance monitoring. This expansion reflects interest in precision nutrition, although evidence supporting clinical benefit in healthy populations remains limited (Liao et al., 2026). The key question is whether additional metabolic data improves outcomes in already well-regulated physiology.

    Physiological Basis of CGM Technology

    CGMs measure glucose in interstitial fluid using enzymatic sensors. Interstitial glucose is physiologically linked to blood glucose but is not identical. A consistent limitation is the time lag between blood and interstitial compartments, typically 5–15 minutes depending on metabolic state and perfusion (Torimoto and Okada, 2021). This lag becomes more pronounced during rapid changes such as postprandial absorption or exercise. Accuracy is also influenced by sensor kinetics, calibration algorithms, and tissue-level variability. Facchinetti (2016) notes that CGM accuracy is generally acceptable in diabetic ranges but is reduced at lower glucose levels and during rapid glycaemic shifts, which are more typical in healthy individuals. This means CGM outputs in normoglycaemic populations should be interpreted as trend-based estimates rather than precise biochemical measurements.

    Inter-Individual Variability in Glycaemic Response

    A key rationale for CGM use in personalised nutrition is inter-individual variability in postprandial glycaemic responses (PPGRs). Zeevi et al. (2015) demonstrated that identical meals produce highly variable glucose responses driven by factors including microbiome composition, insulin sensitivity, sleep, and anthropometrics. Their machine-learning model was able to predict PPGRs and showed that personalised dietary interventions could reduce postprandial glucose excursions. Mendes-Soares et al. (2019) replicated these findings in an independent cohort, confirming that glycaemic responses are highly individualised. Mechanistically, variability reflects differences in gastric emptying, insulin secretion dynamics, hepatic glucose output, and peripheral glucose uptake. However, variability in physiological response does not necessarily imply that reducing all glucose excursions improves long-term health outcomes.

    CGM Effects in Non-Diabetic Populations

    The most comprehensive synthesis of evidence is provided by Liao et al. (2026), who conducted a systematic review and meta-analysis of CGM use in non-diabetic populations. They reported small reductions in mean glucose and improved dietary awareness, but no consistent improvements in BMI, glycaemic variability, or long-term metabolic outcomes in healthy individuals. Benefits were more evident in individuals with impaired glucose regulation, suggesting CGM utility may be dependent on baseline metabolic status. These findings indicate CGMs function more effectively as behavioural feedback tools than as metabolic intervention devices in healthy populations.

    Do Postprandial Glucose Spikes Matter?

    Postprandial increases in glucose are a normal physiological response to carbohydrate ingestion. In healthy individuals, glucose homeostasis is maintained through coordinated insulin secretion, hepatic regulation, and peripheral uptake. DeFronzo et al. (2015) describe these responses as central to metabolic flexibility rather than pathological dysfunction. While glycaemic variability has been associated with adverse outcomes in diabetic populations, causality in healthy individuals is not established. No randomised controlled trials demonstrate that reducing physiological glucose excursions improves cardiovascular outcomes, body composition, or longevity in normoglycaemic populations.

    CGM Accuracy and Interpretation Limitations

    CGM interpretation is limited by both physiological and technical factors. Interstitial lag introduces temporal discrepancy between blood and tissue glucose (Torimoto and Okada, 2021). Sensor accuracy decreases during rapid glucose fluctuations and at lower glucose ranges (Facchinetti, 2016). In healthy individuals, where glucose variability is relatively small, these limitations may disproportionately influence interpretation, increasing the risk of misclassifying normal physiological variation as meaningful metabolic disturbance.

    Behavioural and Psychological Considerations

    CGMs provide continuous physiological feedback, which can influence behaviour. Vettoretti et al. (2020) highlight that while CGMs may improve awareness of dietary patterns, continuous monitoring can also increase cognitive load and attention bias toward short-term fluctuations. This may lead to over-interpretation of normal glucose variability, increased dietary restriction, and reduced dietary flexibility in some individuals. Importantly, there is no evidence that focusing on minimising all glucose excursions improves dietary quality or long-term health outcomes in healthy populations.

    CGMs in Sport and Exercise

    CGMs are increasingly used in athletic populations to monitor carbohydrate availability, fuelling strategies, and recovery nutrition. However, exercise significantly alters glucose kinetics through catecholamine-mediated hepatic glucose output, increased skeletal muscle uptake, and changes in insulin sensitivity. These physiological responses complicate interpretation of CGM data during training and recovery. Jeukendrup (2017) notes that while carbohydrate availability is central to performance, there is no strong evidence that CGM-guided nutrition improves athletic performance outcomes in controlled trials.

    Future Directions: Precision Nutrition

    CGMs are being integrated into precision nutrition models alongside microbiome and dietary data. Zeevi et al. (2015) and Mendes-Soares et al. (2019) demonstrated that machine-learning approaches can predict individual glycaemic responses with moderate accuracy, supporting the concept of metabolic phenotyping. However, translation into clinical practice remains limited due to lack of long-term outcome data, limited external validity, and absence of large-scale randomised controlled trials demonstrating clinical benefit.

    Practical Implications

    Current evidence suggests CGMs may improve short-term dietary awareness and engagement behaviours (Liao et al., 2026). Individual variability in glycaemic response is well established (Zeevi et al., 2015), but does not justify routine intervention in healthy populations. Physiological glucose excursions are not inherently harmful (DeFronzo et al., 2015). CGM data must be interpreted cautiously due to physiological lag and measurement limitations (Facchinetti, 2016). Behavioural effects may be beneficial or maladaptive depending on the individual context (Vettoretti et al., 2020).

    Are CGMs Worth Using in Healthy Individuals?

    In healthy individuals, CGMs are not currently supported as a routine metabolic optimisation tool. Evidence suggests their primary value is educational and behavioural rather than clinical. They may help increase awareness of dietary patterns and individual variability but do not currently demonstrate improvements in body composition, performance, or long-term health outcomes (Liao et al., 2026). In individuals with impaired glucose regulation, CGMs may have greater utility as part of lifestyle intervention strategies. In athletes, CGMs may provide descriptive insights into fuelling responses but lack evidence for performance enhancement. Overall, CGMs should be considered informational rather than interventional tools in healthy populations.

    Conclusion

    Continuous glucose monitoring is a well-established clinical tool in diabetes management and an emerging technology in personalised nutrition. However, current evidence does not support routine use in healthy individuals for improving metabolic health, performance, or body composition. While CGMs provide valuable insight into inter-individual variability in glycaemic responses, physiological glucose excursions in healthy individuals are not inherently pathological, and the clinical significance of modifying them remains unproven. CGMs are best viewed as research and educational tools rather than essential health optimisation devices in normoglycaemic populations.

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    References

    Battelino, T., Danne, T., Bergenstal, R.M., Amiel, S.A., Beck, R., Biester, T., et al. (2019) ‘Clinical targets for continuous glucose monitoring data interpretation: recommendations from the international consensus on time in range’, Diabetes Care, 42(8), pp. 1593–1603.

    Beck, R.W., Riddlesworth, T.D., Ruedy, K., Ahmann, A., Bergenstal, R., Haller, S. (2017) ‘Effect of continuous glucose monitoring on glycemic control in adults with type 1 diabetes using insulin injections’, Annals of Internal Medicine, 167(6), pp. 365–374.

    DeFronzo, R.A., Ferrannini, E., Groop, L., Henry, R.R., Herman, W.H., Holst, J.J., et al. (2015) ‘Type 2 diabetes mellitus’, Diabetes Care, 38(1), pp. 142–150.

    Facchinetti, A. (2016) ‘Continuous glucose monitoring sensors: past, present and future algorithmic challenges’, Sensors, 16(12), 2098.

    Jeukendrup, A.E. (2017) ‘Periodized nutrition for athletes’, Sports Medicine, 47(S1), pp. 51–63.

    Liao, X., et al. (2026) ‘Continuous glucose monitoring in non-diabetic individuals: systematic review and meta-analysis’, European Journal of Medical Research, 31, pp. 1–15.

    Mendes-Soares, H., et al. (2019) ‘Assessment of a personalized approach to predicting postprandial glycemic responses’, Cell Host & Microbe, 26(3), pp. 424–435.

    Torimoto, K. and Okada, Y. (2021) ‘Accuracy and limitations of continuous glucose monitoring systems’, Diabetology International, 12, pp. 1–10.

    Vettoretti, M., Facchinetti, A. and Sparacino, G. (2020) ‘Continuous glucose monitoring: interpretation and behavioural implications’, Diabetes Technology & Therapeutics, 22(9), pp. 1–10.

    Zeevi, D., Korem, T., Zmora, N., Israeli, D., Rothschild, D., Weinberger, A., et al. (2015) ‘Personalized nutrition by prediction of glycemic responses’, Cell, 163(5), pp. 1079–1094

  • Peptides in the Fitness Industry: Mechanisms, Adaptation, Evidence, Risks and Scientific Limitations.

    Peptides in the Fitness Industry: Mechanisms, Adaptation, Evidence, Risks and Scientific Limitations.

    Peptides have moved rapidly from biomedical research into mainstream fitness culture, marketed as a targeted means of enhancing muscle growth, recovery and overall physiological function. They are often presented as a “precision” alternative to traditional performance-enhancing approaches, promising specific, controllable effects with fewer risks. However, a closer examination of the scientific literature reveals a more complex and far less certain picture. While peptide biology is well understood at a mechanistic level, the evidence supporting meaningful improvements in training adaptation and athletic performance is limited, inconsistent and frequently constrained by methodological weaknesses. The key issue is therefore not whether peptides can influence physiology, but whether they meaningfully improve adaptation to training, which remains the primary determinant of performance outcomes.

    What Are Peptides

    Peptides are short chains of amino acids that function predominantly as signalling molecules within the body. Unlike larger proteins, which primarily serve structural or enzymatic roles, peptides regulate biological processes by binding to receptors and initiating intracellular responses. A number of critical physiological regulators are peptides, including insulin and insulin-like growth factor‑1, which plays a central role in skeletal muscle growth, regeneration and adaptation through its influence on satellite cell activity and protein synthesis pathways (Ahmad et al., 2020). In applied fitness settings, peptides typically refer to synthetic analogues designed to manipulate these signalling systems, often through hormonal or regenerative pathways.

    Mechanisms of Action

    The Growth Hormone–IGF‑1 Axis

    The most extensively discussed mechanism underpinning peptide use in fitness is the growth hormone–IGF‑1 axis. Growth hormone is secreted from the pituitary gland and stimulates the production of IGF‑1 both systemically and within muscle tissue. IGF‑1 then binds to receptors on muscle cells, activating intracellular pathways such as PI3K/Akt and mTOR, which regulate protein synthesis, cell proliferation and survival (Machida and Booth, 2004; Ahmad et al., 2020). Through these mechanisms, IGF‑1 facilitates satellite cell activation, muscle fibre hypertrophy and tissue repair following damage.

    Interaction With Exercise Physiology

    Resistance exercise itself strongly activates the same pathways targeted by peptides. Mechanical loading increases local IGF‑1 expression within muscle tissue and stimulates mTOR signalling, which is central to muscle protein synthesis (Machida and Booth, 2004). This highlights an important limitation: peptides are not introducing new biological mechanisms but attempting to manipulate systems already maximally stimulated through appropriate training and nutrition.

    Tissue Repair and Regeneration Pathways

    Some peptides are proposed to influence recovery through mechanisms such as angiogenesis, enhanced collagen synthesis, modulation of inflammatory pathways and improved fibroblast activity. These mechanisms underpin claims relating to improved healing of connective tissues and reduced injury recovery time. However, the evidence supporting these claims is heavily dominated by preclinical animal research, with limited high-quality human validation.

    Training Adaptation: The Central Issue

    Training adaptation is a multifactorial process driven by the interaction between mechanical, metabolic and biological signals. It depends on progressive overload, motor unit recruitment, neuromuscular adaptation, nutrient availability and recovery processes rather than a single signalling pathway. Peptides influence only a narrow component of this system, primarily intracellular signalling.

    Adaptation follows a sequence whereby a sufficient training stimulus produces intracellular signalling, leading to protein synthesis, structural change and ultimately functional improvement. Peptides act at the signalling stage but do not replace the initial mechanical stimulus. This leads to a critical principle: increasing signalling alone does not produce meaningful adaptation in the absence of appropriate training.

    A consistent finding across the literature is the discrepancy between molecular responses and functional outcomes. Studies often demonstrate increases in IGF‑1, activation of anabolic signalling pathways and changes in gene expression, yet these do not consistently translate into increased strength, improved power output or enhanced performance. For example, collagen peptide studies show increased signalling pathway activation without significant improvements in strength or functional performance (Centner et al., 2022; Balshaw et al., 2022). This highlights that molecular changes are necessary but not sufficient for meaningful adaptation.

    Adaptation is also constrained by limiting factors such as training stimulus, protein intake, energy availability and recovery. Peptides do not override these constraints, meaning increased signalling cannot compensate for inadequate training or nutrition. Additionally, most peptide studies are conducted in untrained or clinical populations, where adaptive capacity is higher. In trained athletes, physiological systems are already optimised, meaning the marginal benefit of additional signalling is likely to be minimal due to ceiling effects.

    Evidence Base

    Growth Hormone and Related Interventions

    The strongest human evidence comes from research on growth hormone. Randomised controlled trials demonstrate that growth hormone administration can increase lean body mass and reduce fat mass, particularly in ageing or hormone-deficient populations (Hoffman et al., 2004; Fernández‑Garza et al., 2025). However, interpretation of these findings is complex. Growth hormone increases extracellular fluid retention and connective tissue mass, meaning increases in lean mass do not necessarily represent increases in contractile muscle tissue.

    Despite changes in body composition, functional outcomes are inconsistent. Upper-body strength often shows no significant improvement, while lower-body strength gains are modest and variable (Tavares et al., 2013). Performance outcomes are rarely improved, indicating that growth hormone-related hypertrophy is not equivalent to training-induced hypertrophy.

    Growth hormone interventions are also associated with metabolic consequences, including reduced insulin sensitivity and impaired glucose tolerance (Fernández‑Garza et al., 2025). These findings raise concerns regarding long-term health risks and highlight the importance of risk–benefit analysis.

    Collagen Peptides and Resistance Training

    Research on collagen peptides provides additional insight into the disconnect between molecular signalling and functional outcomes. Acute studies demonstrate increased activation of anabolic signalling pathways following collagen supplementation and resistance exercise (Centner et al., 2022). However, longer-term studies show increases in muscle volume without corresponding improvements in strength or performance (Balshaw et al., 2022). This suggests that structural changes at the tissue level do not necessarily translate into functional improvements.

    Protein Versus Peptides

    Comparative studies consistently demonstrate that protein quality and quantity are more important determinants of adaptation than peptide supplementation. Whey protein has been shown to produce greater increases in muscle size than collagen peptides, despite matched leucine content, while strength gains remain similar (Jacinto et al., 2022). This reinforces established principles of sports nutrition, where total protein intake and amino acid availability drive adaptation.

    Recovery Peptides

    Recovery peptides such as BPC‑157 are widely discussed within fitness circles but lack robust human evidence. Systematic reviews indicate that the majority of studies are preclinical, with very few human trials and a lack of randomised controlled evidence (Vasireddi et al., 2025). Narrative reviews further confirm that although animal models demonstrate promising effects, these findings have not been reliably replicated in humans (McGuire et al., 2025). Current claims regarding recovery peptides are therefore not supported by strong clinical data.

    Study Design Limitations

    The peptide evidence base is limited by consistent methodological issues. Many studies involve small sample sizes, reducing statistical power and increasing variability. Research is often conducted in non-athletic populations, limiting applicability to trained individuals. Study durations are typically short, preventing long-term conclusions about adaptation or safety.

    There is a heavy reliance on surrogate outcomes such as lean body mass, hormone concentrations and gene expression, which do not necessarily reflect real-world performance outcomes. Confounding variables such as training programme design, nutritional intake and recovery practices are often not well controlled. Additionally, there is a lack of replication across independent studies and a significant translational gap between animal and human research, particularly in recovery peptide investigations.

    Safety Considerations

    Acute risks include fluid retention, impaired glucose metabolism, reduced insulin sensitivity and injection-related complications. Chronic risks are less well understood but potentially more serious. IGF‑1 promotes cell proliferation and inhibits apoptosis, and chronic elevation is associated with increased cancer risk (Ahmad et al., 2020). Long-term concerns also include cardiovascular strain, endocrine disruption and metabolic dysfunction. A key limitation is the absence of long-term human safety data, meaning the true risk profile remains unclear.

    Practical Implications

    Peptides should not be considered first-line interventions for performance enhancement. Training, nutrition and recovery remain the primary drivers of adaptation. Peptides should be viewed as experimental due to the limited and inconsistent evidence base. The risk–reward profile is currently unfavourable, with modest potential benefits and uncertain long-term risks.

    Practitioners should prioritise evidence-based strategies and educate athletes on the limitations of current knowledge. Any consideration of peptide use should occur within a medically supervised context. Focus should remain on progressive resistance training, adequate protein intake, creatine supplementation and sleep optimisation, all of which are supported by high-quality evidence.

    Final Conclusion

    Peptides are biologically plausible and mechanistically sound, influencing key pathways involved in muscle growth and recovery. However, the current evidence indicates that they do not meaningfully enhance training adaptation or performance beyond what can be achieved through well-structured training and nutrition.

    The literature is constrained by methodological weaknesses, non-athletic populations, reliance on surrogate outcomes and limited long-term data. At the same time, safety concerns remain unresolved.

    From a performance perspective, peptides do not replace training, do not reliably enhance adaptation and should currently be regarded as experimental rather than evidence-based tools. The fundamentals of performance continue to provide the most effective and reliable outcomes.

    References

    Ahmad, S.S. et al. (2020) Implications of insulin-like growth factor‑1 in skeletal muscle and various diseases. Cells, 9(8), 1773

    Balshaw, T.G. et al. (2022) The effect of specific bioactive collagen peptides on function and muscle remodeling during human resistance training. Acta Physiologica

    Centner, C. et al. (2022) Supplementation of specific collagen peptides following high-load resistance exercise upregulates gene expression. Frontiers in Physiology

    Fernández‑Garza, L.E. et al. (2025) Growth hormone and aging: a clinical review. Frontiers in Aging

    Hoffman, A.R. et al. (2004) Growth hormone replacement therapy in adult-onset GH deficiency. Journal of Clinical Endocrinology & Metabolism

    Jacinto, J.L. et al. (2022) Whey protein supplementation is superior to leucine-matched collagen peptides. International Journal of Sport Nutrition and Exercise Metabolism

    Machida, S. and Booth, F.W. (2004) Insulin-like growth factor‑1 and satellite cell proliferation. Proceedings of the Nutrition Society

    McGuire, F.P. et al. (2025) Regeneration or risk? A narrative review of BPC‑157. Current Reviews in Musculoskeletal Medicine

    Tavares, A.B. et al. (2013) Effects of growth hormone administration on muscle strength. International Journal of Endocrinology

    Vasireddi, S. et al. (2025) Systematic review of BPC‑157 for orthopaedic applications. American Journal of Sports Medicine

  • Behaviour Change and Nutrition: The Key to Consistency

    Whether you’re aiming to build muscle, lose fat, or enhance performance, your nutrition habits are just as important as your training program. But sticking to a diet plan whether it’s a bulking phase, a cutting cycle, or performance nutrition can be harder than hitting a heavy squat. The real challenge isn’t knowing what to eat; it’s changing your behaviour to make it happen consistently.

    This is where behaviour change science comes in. Grounded in psychology, behaviour change strategies can help gym goers, athletes and well honestly, anyone! overcome common barriers like poor planning, low motivation, and decision fatigue turning good intentions into real results.

    Why Motivation Alone Isn’t Enough

    You might start a new meal plan feeling motivated and ready. But motivation fluctuates. To stay consistent long-term, you need more than willpower you need systems and strategies.

    According to the COM-B model, behaviour is driven by three things: Capability, Opportunity, and Motivation (Michie et al., 2011). In a gym context, this might look like:

    Capability: Do you have the cooking skills and nutrition knowledge? Opportunity: Is your environment helping or hindering your eating goals? Motivation: Are you clear on why you’re doing this?

    Addressing all three areas sets you up for long-term adherence not just short-term compliance.

    Habit Formation and Meal Consistency

    For athletes and recreational lifters, habit formation is key. The Health Action Process Approach (HAPA) highlights the difference between intention and action. You might plan to prep meals or hit your macros but without planning, tracking, and adjusting, those intentions often fall flat (Schwarzer, 2008).

    Using tools like MyFitnessPal (or other apps), food scales, and prep routines helps build consistency. Research shows that self-monitoring—tracking what you eat—is one of the most powerful predictors of success in fat loss and muscle gain (Chen et al., 2023).

    Digital Tools for Diet Adherence

    A 2023 meta-analysis confirmed that using nutrition tracking apps significantly improves dietary behaviours and outcomes in people aiming to lose fat or gain lean mass (Chen et al., 2023). These tools don’t just count calories they give real-time feedback, help you spot trends, and reinforce accountability.

    Other behaviour change techniques (BCTs) proven to support gym-related goals include:

    SMART goal-setting (Specific, Measurable, Achievable, Relevant, Time-bound)

    If then planning (e.g., “If I get hungry post-workout, then I’ll have a protein shake”)

    Social support (training partners or online communities)

    Why Most Meal Plans Fail (And How to Fix It)

    Many people fall off their meal plans not because they’re “lazy” or “undisciplined,” but because their approach doesn’t match their lifestyle or values. According to the Theory of Planned Behaviour (TPB), intentions alone aren’t enough people must also believe they have control over their environment and the ability to follow through (Ajzen, 1991).

    That’s why environmental restructuring like prepping meals in advance, keeping snacks out of sight, or having protein options ready post-training is critical. Your environment should make the right choice the easy choice.

    The Bigger Picture: Stress, Sleep, and Social Support

    Behaviour change science also reminds us that diet doesn’t happen in isolation. Poor sleep, stress, or a lack of social support can derail even the best plan. The Science of Behavior Change (SOBC) program by NIH highlights how self-regulation, stress management, and habit loops can be modified to enhance results (NIH, 2023).

    In other words, you don’t need to grind harder you need to train smarter, eat smarter, and structure your environment and mindset for success.

    Conclusion

    If you’ve ever struggled to stay consistent with your nutrition while training hard, you’re not alone and you’re not lacking discipline. You’re just missing the behaviour change strategies that align your habits with your goals.

    By applying science-based models like COM-B, HAPA, and TPB, and using tools like tracking apps, habit systems, and structured planning, you can finally bridge the gap between training and nutrition and unlock your full potential in the gym.

    If you want structured support to improve nutrition behaviour change and long term performance, get in touch

    Contact me

    References

    Ajzen, I., 1991. The theory of planned behavior. Organizational Behavior and Human Decision Processes, 50(2), pp.179–211.

    Chen, J., Cade, J.E. and Allman-Farinelli, M., 2023. The effectiveness of nutrition apps in improving dietary behaviours and health outcomes: a systematic review and meta-analysis. Public Health Nutrition, 26(1), pp.1–12.

    Greaves, C.J., Sheppard, K.E., Abraham, C., Hardeman, W., Roden, M., Evans, P.H. and Schwarz, P., 2011. Systematic review of reviews of intervention components associated with increased effectiveness in dietary and physical activity interventions. BMC Public Health, 11(1), p.119.

    Lee, R.M., Fischer, C., Caballero, P., and Andersson, E., 2022. Behaviour change nutrition interventions and their effectiveness: a systematic review of global public health outcomes. PLOS Global Public Health, 2(9), p.e0000401.

    Michie, S., Atkins, L., and West, R., 2014. The Behaviour Change Wheel: A Guide to Designing Interventions. London: Silverback Publishing.

    Michie, S., van Stralen, M.M. and West, R., 2011. The behaviour change wheel: A new method for characterising and designing behaviour change interventions. Implementation Science, 6(1), p.42.

    NIH Common Fund, 2023. Science of Behavior Change (SOBC). [online] Available at: https://commonfund.nih.gov/science-behavior-change-sobc [Accessed 18 May 2025].

    Schwarzer, R., 2008. Modeling health behavior change: How to predict and modify the adoption and maintenance of health behaviors. Applied Psychology, 57(1), pp.1–29.

  • Citrulline Malate and Performance: The Science Behind the Pump

    By Chris Clayton, PhD, SENr, Performance Nutritionist.

    As a performance nutritionist, I’ve worked with athletes across disciplines cycling, boxing, MMA, and football. One supplement I consistently see delivering results, especially in high-intensity and strength focused training, is citrulline malate. Unlike many so-called “pre-workout” compounds, this one stands up to scrutiny. So let’s take a deep dive into what citrulline malate is, how it works, and what the science really says about its impact on performance.

    What Is Citrulline Malate?

    Citrulline malate is a combination of two compounds:

    L-Citrulline: A non-essential amino acid that’s a precursor to L-arginine. It’s more effective than direct arginine supplementation at boosting nitric oxide (NO) levels due to better absorption and bioavailability. Malate (Malic Acid): A key intermediate in the tricarboxylic acid (TCA) cycle, also known as the Krebs cycle, which plays a central role in energy production.

    Together, this combo supports both anaerobic and aerobic performance by enhancing blood flow, buffering fatigue, and improving energy efficiency.

    Mechanisms of Action: How It Works

    Here’s how citrulline malate contributes to performance:

    Nitric Oxide Boost via Arginine Pathway: Supplementing with citrulline increases plasma L-arginine and nitric oxide more effectively than arginine itself (Schwedhelm et al., 2008). Higher NO levels result in vasodilation, which increases oxygen and nutrient delivery to working muscles, improving endurance and reducing fatigue. Ammonia and Lactate Clearance: Citrulline helps detoxify ammonia through the urea cycle, delaying the onset of fatigue (Sureda et al., 2010). This is particularly important during high-volume resistance training or repeated sprint bouts. Enhanced ATP Production via Malate: Malate supports mitochondrial energy production. It facilitates the regeneration of NAD+, a coenzyme essential for ATP generation, especially under aerobic conditions.

    What the Research Says

    1. Strength and Resistance Training

    Pérez-Guisado & Jakeman (2010): In this double-blind, placebo-controlled study, 8g of citrulline malate taken 1 hour before upper-body resistance training significantly increased the number of repetitions completed (by ~52.92%) and reduced muscle soreness at 24 and 48 hours post-training. Wax et al. (2015): Male subjects performing leg resistance training saw improved repetitions and reduced fatigue when supplemented with 8g of citrulline malate. This confirmed earlier findings and suggested a strong role in muscular endurance.

    2. Endurance Performance

    Bailey et al. (2015): A 6g dose of citrulline increased plasma nitrate and nitrite, improved VO2 kinetics, and reduced oxygen cost during moderate-intensity cycling. This means athletes required less oxygen to perform the same amount of work an efficiency gain that matters in endurance sports. Glenn et al. (2016): In this study on recreationally active males, a single 8g dose improved cycling time to exhaustion and reduced ratings of perceived exertion (RPE). Athletes felt they were working less hard to achieve the same output.

    3. Recovery and Muscle Soreness

    Gonzalez et al. (2018): Citrulline supplementation post-exercise improved blood flow and reduced delayed onset muscle soreness (DOMS), likely due to enhanced nutrient delivery and waste clearance during recovery phases.

    Practical Recommendations: How I Use It with Athletes

    Here’s how I typically program citrulline malate use:

    Dosage: 6–8g taken 30–60 minutes before training. This is the most evidence-backed range. Form: Powdered form is ideal, either standalone or in a pre-workout blend without excessive stimulants. Many commercial pre-workouts under-dose citrulline, so check labels carefully. Timing: Take on an empty stomach pre-training for better absorption. For high-volume training blocks or tournaments, some athletes use it daily for a more sustained effect on recovery. Cycling: While not strictly necessary, I may cycle usage (e.g., 5 days on, 2 days off) during off-season periods or lower training loads, simply to match need and avoid unnecessary supplementation.

    Safety and Side Effects

    Citrulline malate has a strong safety profile. No serious adverse effects have been reported at doses up to 10g per day. It’s stimulant-free, making it a good option for athletes training in the evening or those sensitive to caffeine. Minor side effects like stomach discomfort can occur in some people, particularly at higher doses, but these are rare.

    Final Thoughts

    From the lab to the gym floor, citrulline malate has earned its place as one of the few supplements that actually does what it claims. Whether you’re a strength athlete looking to grind out extra reps, a cyclist chasing improved endurance, or a combat sport athlete managing high training volumes, citrulline malate can offer a genuine performance boost.

    Just like any supplement, it works best when it’s built on a foundation of good nutrition, sleep, and recovery. But if you’re looking for a scientifically supported edge, this one’s worth considering.

    This is a good option that is informed sport so you can be sure it is free from banned substances

    Applied Nutrition Citrulline Malate 2:1

    Key References:

    Pérez-Guisado, J., & Jakeman, P. M. (2010). Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. Journal of Strength and Conditioning Research, 24(5), 1215–1222. Wax, B., et al. (2015). Effects of supplemental citrulline malate ingestion during repeated bouts of lower-body exercise. European Journal of Sport Science, 15(1), 45–52. Bailey, S. J., et al. (2015). Dietary nitrate supplementation reduces the O2 cost of low-intensity exercise and enhances tolerance to high-intensity exercise in humans. Journal of Applied Physiology, 107(4), 1144–1155. Glenn, J. M., et al. (2016). Acute citrulline malate supplementation improves cycling time trial performance in trained cyclists. Journal of Strength and Conditioning Research, 30(4), 1097–1103. Sureda, A., et al. (2010). L-Citrulline-malate influence over branched chain amino acid utilization during exercise. European Journal of Applied Physiology, 110(2), 341–351. Gonzalez, A. M., et al. (2018). Effects of citrulline supplementation on exercise performance in humans: A review of the current literature. Journal of Strength and Conditioning Research, 32(2), 385–391.

  • The Foundations of Performance Nutrition: Why Timing, Type, and Total Matter

    When it comes to enhancing performance whether in sport, exercise, or day-to-day energy demands nutrition is far more than just “eating healthy.” It’s a science-driven approach that focuses on fuelling the body in a strategic way to optimise energy, recovery, strength, and endurance. At the core of performance nutrition lies three crucial pillars: timing, type, and total intake. When these elements are aligned, they create a powerful framework to support physical performance and recovery. Let’s break each of these down.

    1. Timing: When You Eat Matters

    Nutrient timing is all about when you eat in relation to training or activity. Eating the right foods at the right times can enhance energy availability, reduce fatigue, and accelerate recovery.

    Pre-training: Fuel up with a mix of carbohydrates and a small amount of protein 1–3 hours before exercise to ensure glycogen stores are topped up and muscles are primed. During training: For longer sessions (especially over 60–90 minutes), intra-workout nutrition like simple carbs and fluids can help maintain energy and hydration. Post-training: Recovery nutrition is vital. Consuming carbs and protein within 30–60 minutes post-exercise helps replenish glycogen stores and kickstarts muscle repair.

    Ignoring nutrient timing can lead to under-fuelling, sluggish sessions, and prolonged recovery.

    2. Type: What You Eat Matters

    All calories are not created equal especially when it comes to performance. The type of macronutrients (carbohydrates, proteins, and fats) and micronutrients (vitamins and minerals) you consume plays a major role in how your body performs.

    Carbohydrates are the body’s preferred source of energy during high-intensity activity. Think whole grains, fruits, starchy veg, and sports-specific fuel like energy gels when needed. Protein is essential for muscle repair, growth, and overall recovery. Aim for lean protein sources like poultry, eggs, dairy, legumes, and plant-based alternatives. Fats, while often overlooked, are key for long-lasting energy and hormone function especially in endurance athletes. Prioritise healthy fats like avocado, nuts, seeds, and oily fish. Hydration and electrolytes are just as important as food without them, energy and focus can quickly drop.

    Matching the type of food to your activity and goals helps the body perform efficiently and recover faster.

    3. Total: How Much You Eat Matters

    Even with perfect timing and the right types of food, performance can still suffer if you’re under-fuelling or over-fuelling. Your total intake the quantity of calories and nutrients needs to align with your energy output and individual goals.

    Under-eating can lead to low energy availability, poor recovery, fatigue, and increased injury risk. Over-eating may cause sluggishness, weight gain, and reduced performance in sports that require speed or agility. Individual needs vary depending on training intensity, frequency, body composition goals, and metabolic rate there’s no one-size-fits-all.

    Working with a nutritionist or using tracking tools can help athletes find the sweet spot that meets their specific energy demands.

    Final Thoughts: The Big Picture

    Performance nutrition isn’t just about what you eat it’s a strategic combination of when, what, and how much you eat. These three pillars timing, type, and total are the backbone of effective fuelling for performance. Whether you’re training for a marathon, lifting heavy in the gym, or simply looking to feel more energised and focused in your daily life, getting these fundamentals right is essential.

    By fine-tuning these elements, you’re not just eating you’re fuelling with purpose.

  • Caffeine: Mechanisms of Action and Its Impact on Performance and Recovery

    Introduction

    Caffeine, a widely consumed ergogenic aid, is known for its ability to enhance both physical and cognitive performance. Its use is common among athletes aiming to improve endurance, strength, and recovery (Grgic, 2021). This article explores the mechanisms of caffeine action, its impact on endurance and resistance training, and its role in post-exercise recovery.

    Mechanisms of Action

    Caffeine exerts its effects through several key physiological mechanisms:

    Adenosine Receptor Antagonism:

    Caffeine blocks adenosine receptors (A1 and A2A) in the central nervous system, reducing fatigue perception and enhancing neurotransmitter release, particularly dopamine and norepinephrine (Ferreira, da Silva and Bueno, 2021).

    Calcium Mobilization:

    Caffeine increases calcium release from the sarcoplasmic reticulum in muscle cells, leading to enhanced muscle contraction and improved force production (Grgic, 2021).

    Phosphodiesterase Inhibition: By inhibiting phosphodiesterase, caffeine increases cyclic adenosine monophosphate (cAMP) levels, stimulating fat oxidation and preserving glycogen stores (Raya-González et al., 2020).

    Impact on Endurance Performance

    Caffeine is well-documented to improve endurance exercise performance by delaying fatigue and increasing time to exhaustion. Its ability to enhance fat oxidation and spare glycogen contributes to prolonged exercise capacity (Ferreira, da Silva and Bueno, 2021).

    Impact on Resistance Training

    Caffeine also has notable effects on resistance training:

    Muscular Strength:

    Research indicates that caffeine supplementation significantly enhances maximal upper-body strength, particularly in exercises like the bench press, though its effects on lower-body strength are less pronounced (Grgic, 2021).

    Muscular Endurance: Caffeine improves endurance in resistance training, increasing the number of repetitions performed at a given intensity (Ferreira, da Silva and Bueno, 2021).

    Movement Velocity and Power: Studies show that caffeine ingestion enhances movement velocity and power output, particularly in explosive resistance exercises (Raya-González et al., 2020).

    Impact on Recovery

    Caffeine’s influence on recovery is multifaceted:

    Glycogen Resynthesis: When consumed alongside carbohydrates post-exercise, caffeine can enhance muscle glycogen replenishment, expediting recovery (Ferreira, da Silva and Bueno, 2021).

    Pain Reduction: Its analgesic properties may reduce delayed-onset muscle soreness (DOMS), helping athletes recover more efficiently (Grgic, 2021).

    Sleep Disruption: Despite its benefits, excessive caffeine intake—especially later in the day—can negatively impact sleep, which is crucial for muscle recovery and adaptation (Raya-González et al., 2020).

    Conclusion

    Caffeine exerts significant performance-enhancing effects through its impact on the central nervous system, muscle contraction, and energy metabolism. While beneficial for endurance and resistance training, individual responses vary, and careful consideration of dosage and timing is essential to maximise benefits while minimising drawbacks.

    References

    Ferreira, T.T., da Silva, J.V.F. and Bueno, N.B. (2021) ‘Effects of caffeine supplementation on muscle endurance, maximum strength, and perceived exertion in adults submitted to strength training: A systematic review and meta-analysis’, Critical Reviews in Food Science and Nutrition, 61(15), pp. 2587–2600. https://doi.org/10.1080/10408398.2020.1781051. Grgic, J. (2021) ‘Effects of caffeine on resistance exercise: A review of recent research’, Sports Medicine, 51(11), pp. 2281–2298. https://doi.org/10.1007/s40279-021-01493-9. Raya-González, J., Rendo-Urteaga, T., Domínguez, R., Castillo, D., Rodríguez-Fernández, A. and Grgic, J. (2020) ‘Acute effects of caffeine supplementation on movement velocity in resistance exercise: A systematic review and meta-analysis’, Sports Medicine, 50(4), pp. 717–729. https://doi.org/10.1007/s40279-019-01211-9.

  • Understand HMB, Benefits, Mechanisms and Safety

    A former athlete I worked with popped up the other day asking if he should start taking HMB to increase muscle mass. I wish I could have given him a straight yes or no but generally if your aim is to lose body fat then HMB may help with preserving lean tissue. However, research is far from definitive in support of its efficacy.

    Beta-hydroxy-beta-methylbutyrate (HMB) is a metabolite of the essential amino acid leucine, recognized for its potential to enhance muscle health and performance. I will attempt to delve into the current scientific understanding of HMB, exploring its benefits, mechanisms of action, and safety profile.

    Benefits of HMB Supplementation

    1. Muscle Mass and Strength Enhancement

    Research indicates that HMB supplementation can lead to significant improvements in muscle mass and strength. An umbrella review of meta-analyses by Bideshki et al. (2025) found that HMB supplementation resulted in increases in fat-free mass and muscle strength index. These findings suggest that HMB can be particularly beneficial for individuals experiencing muscle atrophy due to various physiological conditions. 

    2. Attenuation of Muscle Loss in Clinical Conditions

    Loss of skeletal muscle mass and muscle weakness are common in various clinical conditions, leading to impaired physical function. A systematic review and meta-analysis by Rowlands et al. (2019) involving 2,137 patients demonstrated that HMB supplementation increased muscle mass and strength, although the effect sizes were small. This suggests that HMB could be a valuable nutritional intervention for preserving muscle health in clinical populations and athletic populations.

    3. Reduction of Exercise-Induced Muscle Damage

    HMB has been shown to reduce muscle damage associated with intense physical activity, thereby accelerating recovery. The International Society of Sports Nutrition’s position stand, as outlined by Wilson et al. (2013), highlights that HMB supplementation decreases post-exercise muscle damage and enhances recovery, making it beneficial across various sports disciplines, regardless of age or sex.  

    Mechanisms of Action

    The anabolic effects of HMB are primarily attributed to its role in protein metabolism. HMB stimulates protein synthesis while attenuating protein degradation in skeletal muscle, potentially leading to muscle hypertrophy and improved strength. Additionally, HMB supplementation has been associated with reductions in total cholesterol, LDL cholesterol, and systolic blood pressure, suggesting potential cardiovascular benefits

    Safety and Dosage

    HMB supplementation is generally considered safe for consumption. The International Society of Sports Nutrition’s position stand by Wilson et al. (2013) reports that a daily intake of 3g per day is well-tolerated without adverse effects on tissue health and function. However, individuals may experience mild gastrointestinal issues, and it is advisable to consult an SENr/AfN registered Nutritionist before starting any new supplement regimen. The combination of HMB with other supplements, such as vitamin D, creatine has also been explored for potential synergistic effects on muscle health, highlighting some positive results.

    Before you decide if HMB is worth adding to your nutrition strategy ask yourself, am I getting the fundamentals right? I.e consuming enough high quality protein, fuelling your training correctly, recovering efficiently? If you answer no to any one of those then HMB may not be for you until you address the fundamental gaps.

    Conclusion

    HMB emerges as a promising supplement for enhancing muscle mass, strength, and recovery, particularly in populations susceptible to muscle loss, such as older adults and those undergoing intense physical training. Its safety profile and potential additional benefits, including cardiovascular improvements, make it a valuable consideration for individuals aiming to optimize muscle health providing the fundamentals (Timing, Type, Total Amount) are maximised. As with any supplement, it is essential to consult with a SENr/AfN registered nutritionist to tailor interventions to individual health needs, conditions and trained status.

    References

    1. Bideshki, A., Bagheri, R., Rashidlamir, A., Motevalli, M. S., & Wong, A. (2025). Ergogenic Benefits of β-Hydroxy-β-Methyl Butyrate (HMB) Supplementation on Body Composition and Muscle Strength: An Umbrella Review of Meta-Analyses. Journal of Cachexia, Sarcopenia and Muscle, 16(2), 123-135. 

    2. Rowlands, D. S., Thomson, J. S., Timmons, B. W., Raymond, F., Fuerholz, A., Mansourian, R., Zwahlen, R., Metairon, S., Glover, E., & Tarnopolsky, M. A. (2019). β-Hydroxy-β-methylbutyrate and its impact on skeletal muscle mass and physical function in clinical practice: a systematic review and meta-analysis. The American Journal of Clinical Nutrition, 109(4), 1119-1132. 

    3. Wilson, J. M., Lowery, R. P., Joy, J. M., Andersen, J. C., Wilson, S. M., Stout, J. R., & Duncan, N. (2013). International Society of Sports Nutrition Position Stand: beta-hydroxy-beta-methylbutyrate (HMB). Journal of the International Society of Sports Nutrition, 10(1), 6. 

    4. Nissen, S. L., & Sharp, R. L. (2000). β-Hydroxy-β-methylbutyrate (HMB) supplementation in humans is safe and may decrease cardiovascular risk factors. The Journal of Nutrition, 130(8), 1937-1945.