Dietary Supplementation in Sport and Exercise : Evidence, Safety and Ergogenic Benefits

Dietary Supplementation in Sport and Exercise removes the myths associated with many dietary supplements. It provides an evidence-based approach to the physiological mechanisms related to popular supplements and examines the ergogenic benefits in both competitive and recreational athletes. This text covers a variety of supplements, including vitamins and minerals, carbohydrates, protein and amino acids, beta-alanine, creatine and guanidinoacetic acid, caffeine and probiotics, as well as emerging ergogenic aids. Information on dosage, ceiling effects and washout periods is discussed, along with safety and legality for different sporting organizations. The book also offers an insight into the efficacy of certain dietary supplements in unique populations, like children and the elderly. Dietary Supplementation in Sport and Exercise is an important resource for advanced undergraduate and graduate students on exercise science, health and nutrition courses, as well as strength coaches, athletic trainers, nutritionists and personal trainers, and medical professionals who consult with patients on dietary supplementation. Cover Half Title Title Page Copyright Page Table of contents List of Figures List of Tables List of Contributors 1 Dietary supplementation: Prevalence of use, regulation and safety Introduction Dietary supplement use in adolescents Nutritional supplementation use by grade Dietary supplementation use in adults Dietary supplement use by competitive athletes Dietary supplement use by military personnel Safety profiles and adverse events associated with dietary supplementation Contamination issues of dietary supplements Regulation of the dietary supplement industry Conclusion References 2 Vitamins and minerals Introduction Determining micronutrient requirements Multivitamin/mineral supplements Efficacy Important notes Vitamin D Efficacy Important notes Calcium Efficacy Important notes Iron Efficacy Important notes Antioxidants and polyphenols Efficacy Important notes Summary References 3 Carbohydrate supplementation: From basic chemistry to real-world applications Introduction Carbohydrate biochemistry Nomenclature Carbohydrate biochemistry and metabolism Carbohydrate digestion Insulinotropic effects of glucose Metabolism of glucose Glycogen metabolism Carbohydrate intake for performance Historical aspect of carbohydrate Muscle glycogen content in humans and muscle biopsy procedure Carbohydrate intake timing, form, replenishment Carbohydrate loading Classic versus modern approach Alternative carbohydrate strategies – transition to counterculture in modern times Carbohydrate intakes for various athletes Resistance training and the role of carbohydrate Signalling Anabolism and catabolism Insulin receptor substrate activation Endurance athletics and carbohydrate consumption Fuel utilization Central fatigue Mixed fuel/intermittent athletes Carbohydrate supplementation Nutrient timing (resistance training) Nutrient timing (endurance training) Activity 120 minutes Effects of glycaemic index and glycaemic load Supplement vector Sports drinks and gels High versus low insulinergic carbohydrates Multiple transportable carbohydrates Mouth rinse Summary References 4 Protein and amino acids Introduction Physiology of protein and amino acids Protein digestion and absorption Protein types and bioavailability Amino acid pool and protein turnover Efficacy of amino acids Protein timing, dosing and recovery Protein ingestion prior to sleep Safety of protein supplementation Conclusion References 5 ß-hydroxy-ß-methylbutyrate Introduction Metabolism and mechanisms of action Promotion of mTORC1 signalling and muscle protein synthesis Attenuation of muscle protein breakdown Ubiquitin proteasome system and apoptosis HMB effects on TNF-a Growth hormone/IGF-1 axis Cholesterol synthesis and membrane integrity Formulations, pharmacokinetics Dosing and supplemental strategy Muscle damage and functional recovery Immune response HMB chronic training effects Untrained individuals Trained individuals Effects of HMB on aerobic and anaerobic performance HMB in energy restricted states Clinical applications of HMB supplementation Sarcopenia and older adults Chronic muscle wasting conditions Safety and legal issues concerning HMB Summary References 6 Beta-alanine supplementation in sports, exercise and health Introduction Determinants of carnosine content in human skeletal muscle Beta-alanine supplementation Effects of beta-alanine supplementation on exercise performance Influence of exercise duration Influence of athletic status Influence on repeated-sprint and intermittent tasks Influence on strength and resistance exercise Beta-alanine and high-intensity training Safety of beta-alanine supplementation Paraesthesia Muscle taurine and histidine content Other Novel therapeutic effects of beta-alanine supplementation References 7 Creatine supplementation in sport, exercise and health Introduction Basic biochemistry and mechanisms of action Creatine supplementation Supplementation strategies Influence of initial creatine content and diet Influence of exercise Influence of carbohydrate Influence of caffeine Influence of different creatine formulations Effects of creatine supplementation on exercise performance Intermittent exercise Strength and resistance exercise Sport-specific exercise Summary Creatine and other tissues Creatine and the brain Creatine and bone Therapeutic use of creatine Older adults Patient populations Side effects and safety considerations Impact of creatine on renal function Dehydration and thermal dysregulation Generation of carcinogenic and cytotoxic by-products Other side effects (cramping, weight gain, gastrointestinal discomfort) Summary and conclusions References 8 Guanidinoacetic acid in health, sport and exercise Background Efficacy and safety of guanidinoacetic acid Early studies on guanidinoacetic acid Guanidinoacetic acid pharmacokinetics Performance-enhancing effects of guanidinoacetic acid An update on guanidinoacetic acid safety Guanidinoacetic acid versus creatine for tissue bioenergetics Co-administration of guanidinoacetic acid and creatine Open questions Conclusion Acknowledgements References 9 Nitric oxide precursors Introduction Nutritional precursors for the nitric oxide synthase-nitric oxide pathway Ergogenic potential of L-arginine supplementation Ergogenic potential of L-citrulline supplementation Nutritional precursors for the nitrate-nitrite-nitric oxide pathway Ergogenic potential of nitrate supplementation Safety considerations Conclusions References 10 Buffering agents: Sodium bicarbonate, sodium citrate and sodium phosphate Introduction Sodium bicarbonate Physiology of this group of nutrients Dosing patterns Efficacy relating to physical performance Combination of NaHCO3 with other supplements Sodium citrate Sodium citrate dosing patterns The efficiency of sodium citrate on exercise performance Potential health benefits associated with sodium citrate Sodium phosphate Underlying mechanisms and physiology Sodium phosphate and aerobic capacity Endurance performance Sprint performance Issues relating to safety and legality Conclusions References 11 Caffeine Introduction Pharmacokinetics of caffeine Mechanism of action Caffeine and strength/power performance Lifting performance Isometric/isokinetic performance Anaerobic capacity/power Caffeine and endurance performance Total work performed Completion time Time to exhaustion Current trends in caffeine research Caffeine in alternative forms Caffeine gum Mouth rinse and nasal/mouth aerosol sprays Time-release caffeine Caffeine metabolism Legality and safety Conclusions References 12 Energy drinks Introduction Ingredients in energy drinks Ingredients considered to be stimulatory in nature Evodiamine Hordenine Ephedra Ingredients focused on controlling appetite Garcinia cambogia Phenylethylamine Hoodia gordonii extract Green tea extract Yohimbine Tetradecylthioacetic acid 5-hydroxytryptophan Yerba mate extract Efficacy of combination ingredient high energy supplements Safety issues related to energy drink consumption Conclusion References 13 Probiotics Microbiota in the human body Probiotics Microbiota and exercise-immunological perspective The effect of exercise on microbiota Influence of probiotics and exercise on immune suppression Probiotics supplementation and exercise performance Conclusion References 14 Emerging ergogenic aids for strength/power development Introduction Betaine Phosphatidic acid Phosphatidylserine Phosphatidylcholine Phosphatidylethanolamine Krill Oil Summary References 15 Emerging ergogenic aids for endurance activity and weight loss Introduction Quercetin Carnitine L-alanyl-L-glutamine Citrulline Summary References 16 Incorporating dietary supplements with sports-specific training and competition Introduction The role of supplementation for targeted adaptations and competition Alterations to body mass and composition Reducing body mass and fat mass Muscle hypertrophy Anaerobic performance and training Aerobic performance and training Cognitive performance during training and sport Training and performance recovery The role of supplementation across the athlete’s training cycle Conclusions References Index This title removes the myths associated with many dietary supplements. It provides an evidence-based approach to the physiological mechanisms related to popular supplements and examines the ergogenic benefits in both competitive and recreational athletes. This text covers a variety of supplements, including vitamins and minerals, carbohydrates, protein and amino acids, beta-alanine, creatine and guanidinoacetic acid, caffeine and probiotics, as well as emerging ergogenic aids This evidence-based approach to the physiological mechanisms related to popular supplements reviews the ergogenic effects in both competitive and recreational athletes. Written by researchers who have published extensively in this field, the book offers an insight into the efficacy of certain dietary supplements in unique populations.