Current status of body composition assessment in sport: review and position statement on behalf of the ad hoc research working group on body composition health and performance, under the auspices of the I.O.C. In sports involving weight divisions (eg. You may be trying to access this site from a secured browser on the server. For example, in events that are dependent on muscle carbohydrate availability, meals eaten in the day(s) leading up to an event should provide sufficient carbohydrate to achieve glycogen stores that are commensurate with the fuel needs of the event. Your account has been temporarily locked due to incorrect sign in attempts and will be automatically unlocked in These changes appear to be a beneficial adaptation to aerobic training and do not negatively impact performance.79 There is no agreement on the serum ferritin level that corresponds to a problematic level of iron depletion/deficiency, with various suggestions ranging from <10 to <35 ng/mL.86 A thorough clinical evaluation in this scenario is warranted since ferritin is an acute-phase protein that increases with inflammation, but in the absence of inflammation, still serves as the best early indicator of compromised iron status. Since the rate of glycogen resynthesis is only ∼ 5% per hour, early intake of carbohydrate in the recovery period (∼1–1.2 g/kg/h during the first 4–6 hours) is useful in maximizing the effective refueling time.117 As long as total intake of carbohydrate and energy is adequate and overall nutritional goals are met, meals and snacks can be chosen from a variety of foods and fluids according to personal preferences of type and timing of intake.36,117 More research is needed to investigate how glycogen storage might be enhanced when energy and carbohydrate intakes are sub-optimal. Sports nutrition guidelines should also consider the importance of the timing of nutrient intake and nutritional support over the day and in relation to sport rather than general daily targets. Ivy JL, Res PT, Sprague RC, Widzer MO. The timing of carbohydrate intake over the day and in relation to training can also be manipulated to promote or reduce carbohydrate availability.36 Strategies to enhance carbohydrate availability are covered in more detail in relation to competition eating strategies. 19. 34. Eating Well with Canada’s Fod Guide. Bayonne ALIZÉE of Université de Rouen, Mont-Saint-Aignan (UR) | Contact Bayonne ALIZÉE Hawley JA, Schabort EJ, Noakes TD, Dennis SC. Public health guidelines such as the DRIs provide micronutrient intake recommendations for sports dietitians to help athletes avoid both deficiency and safety concerns associated with excessive intake. Phillips SM, Moore DR, Tang JE. 7. This paper is being published concurrently in Medicine & Science in Sports & Exercise® and in the Journal of the Academy of Nutrition and Dietetics, and the Canadian Journal of Dietetic Practice and Research. In: Maughan RJ, ed. Symptoms of heat exhaustion can include anxiety, dizziness, fainting. Altitude exposure (ie, daily or intermittent exposure to >2,000 m, > 6,600 ft) may be a specialized strategy within an athlete’s training program or simply their daily training environment.153 One of the goals of specialized altitude training blocks is to naturally increase red blood cell mass (erythropoiesis) so that greater amounts of oxygen can be carried in the blood to enhance subsequent athletic performances.112 Initial exposure to altitude leads to a decrease in plasma volume with corresponding increases in hemoglobin concentration. Carbohydrates for training and competition. Sundgot-Borgen J, Meyer NL, Lohman TG, et al. Of these, body mass (“weight”) and body composition are often focal points for athletes since they are most able to be manipulated. Position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and athletic performance. We should all aim to eat a healthy, varied diet based on the principles of the Eatwell Guide, and this is also the case when you are active.When physically active, your body will use up more energy (calories). Calcium intakes of 1,500 mg/d and 1,500–2,000 IU/day of vitamin D are needed to optimize bone health in athletes with low energy availability or menstrual dysfunctions.12, Antioxidant nutrients play important roles in protecting cell membranes from oxidative damage. Tipton KD, Rasmussen BB, Miller SL, et al. Furthermore, athletes’ supplementation practices are often guided by family, friends, teammates, coaches, the internet, and retailers, rather than sports dietitians and other sport science professionals.138. Maughan RJ. Some error has occurred while processing your request. 52. Hartman JW, Tang JE, Wilkinson SB, et al. Calcium supplementation should be determined after a thorough assessment of usual dietary intake. Methods: Protein ingestion during exercise and during the pre-exercise period seems to have less of an impact on MPS than the post-exercise provision of protein but may still enhance muscle reconditioning depending on the type of training that takes place. However, exercise-induced adaptations do not appear to maximize oxidation rates since they can be further enhanced by dietary strategies such as fasting, acute pre-exercise intake of fat and chronic exposure to high-fat, low-carbohydrate diets.3 Although there has been historical64 and recently revived65 interest in chronic adaptation to high-fat low carbohydrate diets, the present evidence suggests that enhanced rates of fat oxidation can only match exercise capacity/performance achieved by diets or strategies promoting high carbohydrate availability at moderate intensities,64 while the performance of exercise at the higher intensities is impaired.64,66 This appears to occur as a result of a down-regulation of carbohydrate metabolism even when glycogen is available.67 Further research is warranted both in view of the current discussions65 and the failure of current studies to include an adequate control diet that includes contemporary periodized dietary approaches.68 Although specific scenarios may exist where high-fat diets may offer some benefits or at least the absence of disadvantages for performance, in general they appear to reduce rather than enhance metabolic flexibility by reducing carbohydrate availability and capacity to use it effectively as an exercise substrate. Therefore, a more sophisticated approach is needed to integrate this training/nutrient interaction into the larger training program.33 Finally, while there is support for consuming multiple carbohydrates to facilitate more rapid absorption, evidence to support the choice of special blends of carbohydrate to support increased carbohydrate oxidation during training sessions is premature (Question #9). 135. Therefore, athletes should not be advised to restrict sodium in their post-exercise nutrition particularly when large sodium losses have been incurred. By encouraging athletes to consume a well-chosen diet focused on food variety, sports dietitians can help athletes avoid micronutrient deficiencies and gain the benefits of many other performance-promoting eating strategies. Various attributes of physique (body size, shape and composition) are considered to contribute to success in various sports. Factors that increase energy needs above normal baseline levels include exposure to cold or heat, fear, stress, high altitude exposure, some physical injuries, specific drugs or medications (eg, caffeine, nicotine), increases in fat-free mass and, possibly, the luteal phase of the menstrual cycle.2 Aside from reductions in training, energy requirements are lowered by aging, decreases in fat free mass (FFM), and, possibly, the follicular phase of the menstrual cycle.3. Lee JM, Kim Y, Welk GJ. Competition fluid and fuel. 110. The use of an evidence-based approach provides important added benefits to earlier review methods. Effects of preexercise feedings on endurance performance. Background: A key goal of training is to adapt the body to develop metabolic efficiency and flexibility while competition nutrition strategies focus on providing adequate substrate stores to meet the fuel demands of the event and support cognitive function. 2014 Female Athlete Triad Coalition Consensus Statement on Treatment and Return to Play of the Female Athlete Triad: 1st International Conference held in San Francisco, California, May 2012 and 2nd International Conference held in Indianapolis, Indiana, May 2013. 92. A recent study of NCAA Division 1 swimmers and divers reported that athletes who started at 130 nmol/L and received daily doses of 4,000 IU of vitamin D (100 μg) were able to maintain sufficient status over 6 months (mean change +2.5 nmol/L), while athletes receiving placebo experienced a mean loss of 50 nmol/L.97 Unfortunately, determining vitamin D requirements for optimal health and performance is a complex process. Typically, an intake of 30–60 g/hour provides benefits by contributing to muscle fuel needs and maintaining blood glucose concentrations, although in very prolonged events (2.5+ h) or other scenarios where endogenous carbohydrate stores are substantially depleted, higher intakes (up to 90 g/h) are associated with better performance. Rodriguez NR, DiMarco NM, Langley S; American Dietetic Association; Dietitians of Canada; American College of Sports Medicine: Nutrition and Athletic Performance. Bartlett JD, Hawley JA, Morton JP. 141. J Am Diet Assoc. Similarly, athletes may be hypohydrated at the onset of exercise due to recent, prolonged training sessions in the heat or to multiple events in a day.104,105,108,110. SiS Science in Sport. ), performance tests that are unreliable or irrelevant, poor control of confounding variables, and failure to include recommended sports nutrition practices or the interaction with other supplements.139,141 Even when there is a robust literature on a sports supplement, it may not cover all applications that are specific to an event, environment, or individual athlete. NIH Higher intakes may be indicated for short periods during intensified training or when reducing energy intake.26,39 Daily protein intake goals should be met with a meal plan providing a regular spread of moderate amounts of high-quality protein across the day and following strenuous training sessions. (Series Editor), Brown AC. Above all, the individual athlete should choose a strategy that suits their situation and their past experiences and can be fine-tuned with further experimentation. In: Maughan RJ, ed. 2000 Dec;100(12):1543-56. doi: 10.1016/S0002-8223(00)00428-4. Moore DR, Phillips SM, Slater G. Protein. Through a cascade of events, the metabolic heat generated by muscle contractions during exercise can eventually lead to hypovolemia (decreased plasma/blood volume) and thus, cardiovascular strain, increased glycogen utilization, altered metabolic and CNS function, and a greater rise in body temperature.104–106 Although it is possible to be hypohydrated but not hyperthermic (defined as core body temperature exceeding 40°C; 104°F),107 in some scenarios the extra thermal strain associated with hypohydration can contribute to an increased risk of life-threatening exertional heat illness (heatstroke). In: Deakin V, Burke L, eds. Grape polyphenols supplementation for exercise-induced oxidative stress. The past decade has seen an increase in the number and topics of publications of original research and review, consensus statements from sporting organizations, and opportunities for qualification and accreditation related to sports nutrition and dietetics. 126. 5. Application of this information in a particular situation remains the professional responsibility of the practitioner; the clinical treatments described and recommended may not be considered absolute and universal recommendations. EG has no conflicts of interest to report. It outlines the Academy’s, DC’s and ACSM’s stance on nutrition factors that have been determined to influence athletic performance and emerging trends in the field of sports nutrition. Rather, guidelines should be based around optimal adaptation to specific sessions of training/competition within a periodized program, underpinned by an appreciation of the larger context of athletic goals, nutrient needs, energy considerations, and food choices. A multivitamin/mineral supplement may be appropriate in some cases when these conditions do not exist; for example, if an athlete is following an energy-restricted diet or is unwilling or unable to consume sufficient dietary variety. 65. Carbohydrates and fat for training and recovery. Haymes E. Iron. 96. Mountjoy M, Alonso JM, Bergeron MF, et al. Science Sport Nutrition. There is a growing awareness that adequate dietary strategies are absolute key factors in optimizing exercise training and sports performance. Dietary protein requirements and adaptive advantages in athletes. There is also emerging scientific interest in the biomolecular role of vitamin D in skeletal muscle90 where its role in mediating muscle metabolic function91 may have implications for supporting athletic performance. -. Risks and rewards of dietary supplement use by athletes. Carbohydrate consumed in meals and/or snacks during the 1–4 hours pre-exercise may continue to increase body glycogen stores, particularly liver glycogen levels that have been depleted by the overnight fast.117 It may also provide a source of gut glucose release during exercise.117 Carbohydrate intakes of 1–4 g/kg, with timing, amount, and food choices suited to the individual, have been shown to enhance endurance or performance of prolonged exercise (Table 2).117,119 Generally, foods with a low-fat, low-fiber, and low–moderate protein content are the preferred choice for this pre-event menu since they are less prone to cause gastrointestinal problems and promote gastric emptying.120 Liquid meal supplements are useful for athletes who suffer from pre-event nerves or an uncertain pre-event timetable and thus prefer a more quickly digested option. There is little evidence that antioxidant supplements enhance athletic performance101 and the interpretation of existing data is confounded by issues of study design (eg, a large variability in subject characteristics, training protocols, and the doses and combinations of antioxidant supplements; the scarcity of crossover designs). Woolf K, Manore MM. 147. In some of these sports and others (eg, body building), there is an element of aesthetics in determining performance outcomes. ▪ Dehydration/hypohydration can increase the perception of effort and impair exercise performance; thus, appropriate fluid intake before, during, and after exercise is important for health and optimal performance. Magee MK, Lockard BL, Zabriskie HA, Schaefer AQ, Luedke JA, Erickson JL, Jones MT, Jagim AR. The available evidence suggests that the early intake of high quality protein sources (0.25–0.3 g/kg BW) will provide amino acids to build and repair muscle tissue and may enhance glycogen storage in situations where carbohydrate intake is sub-optimal. Sports nutrition is the study and practice of nutrition and diet with regards to improving anyone's athletic performance. Various tactics can be used to permit or promote low carbohydrate availability including reducing total carbohydrate intake or manipulating the timing of training in relation to carbohydrate intake (eg, training in a fasted state, undertaking two bouts of exercise in close proximity without opportunity for refueling between sessions).38. 152. Athletes should be discouraged from chronic implementation of fat intakes below 20% of energy intake since the reduction in dietary variety often associated with such restrictions is likely to reduce the intake of a variety of nutrients such as fat-soluble vitamins and essential fatty acids,9 especially n-3 fatty acids. 106. This position paper was prepared for members of the Academy of Nutrition and Dietetics, Dietitians of Canada (DC), and American College of Sports Medicine (ACSM), other professional associations, government agencies, industry, and the public. Spriet LL. ▪ A primary goal of competition nutrition is to address nutrition-related factors that may limit performance by causing fatigue and a deterioration in skill or concentration over the course of the event. Claims that extremely high-fat, carbohydrate-restricted diets provide a benefit to the performance of competitive athletes are not supported by current literature. 133. 149. Being appropriately hydrated contributes to optimal health and exercise performance. ASR has received grants to evaluate the efficacy of dietary supplements, serves as a scientific advisor for sports nutrition companies, and received remuneration from companies for presenting evidenced-based nutritional supplement and exercise research at professional conferences. In: Wilson T, Temple N, editors. In sports involving strength and power, athletes strive to gain fat-free mass via a program of muscle hypertrophy at specified times of the annual macro-cycle. 30. 24. ▪ Athletes should consume diets that provide at least the Recommended Dietary Allowance (RDA)/Adequate Intake (AI) for all micronutrients. Alcohol: impact on sports performance and recovery in male athletes. Dietary protein consumed in scenarios of low-carbohydrate availability128 and/or restricted energy intake53 in the early post-exercise recovery period has been found to enhance and accelerate glycogen repletion. 72. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. However, the previous warnings about caffeine as a diuretic appear to be overstated when it is habitually consumed in moderate (e.g. Wentz L, Liu PY, Ilich JZ, Haymes EM. First they should support or promote optimal performance by addressing various factors related to nutrition that can cause fatigue and deterioration in the outputs of performance (eg, power, strength, agility, skill, and concentration) throughout or towards the end of the sporting event. Adequate nutrition is essential to maximize the desired effect from altitude training or to support more chronic exposure to a high altitude environment. All authors report the following competing interests: CMK consults with and receives external funding from companies who sell supplemental protein, has received remuneration from companies for delivering scientific presentations at conferences and writes online, print and other media on topics related to exercise, nutrition and protein for related companies. More work is needed to elucidate the relevance and practicality of protein consumption on subsequent exercise performance and if mechanisms in this context are exclusive to accelerating muscle glycogen synthesis. eCollection 2017. Hawley JA, Burke LM, Phillips SM, Spriet LL. How to minimise the health risks to athletes who compete in weight-sensitive sports review and position statement on behalf of the Ad Hoc Research Working Group on Body Composition, Health and Performance, under the auspices of the IOC Medical Commission. Ruohola JP, Laaksi I, Ylikomi T, et al. 51. Sports dietitian roles and responsibilities. 115. Thirst sensation is often dictated by changes in plasma osmolality and is usually a good indication of the need to drink but not that the athlete is dehydrated.108 Older athletes may present with age-related decreases in thirst sensation and may need encouragement to drink during and post-exercise.104, Although skeletal muscle cramps are typically caused by muscle fatigue, they can occur with athletes from all types of sports in a range of environmental conditions104 and may be associated with hypohydration and electrolyte imbalances.
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