Levels Of Body Composition
The study of body composition historically has been driven by the availability of methods to measure or, more appropriately, to estimate it. Since the early 1980s, considerable progress has been made in the development and refinement of techniques to estimate the composition of the body, so that virtually all components of the body can now be measured. This progress has resulted in the modification of the models that provide the framework for studying body composition. Body composition can be...
Body mass FFM FM
The term lean body mass is occasionally used, but FFM is more appropriate. Lean body mass is a more anatomic concept that includes some essential lipids, whereas FFM is a biochemical concept. This model has had the widest application in the study of body composition, including many studies of athletes. FM is the more labile of the two compartments it is readily influenced by diet and training. A shortcoming of the two-component model is the heterogeneous composition of FFM it includes water,...
Spectrum of Menstrual Function
The 1997 Triad Position Stand included only the extreme end point of menstrual dysfunction ie, amenorrhea 2 . The proposed revised triad uses the term menstrual dysfunction to depict more accurately the spectrum of menstrual irregularities that can plague female athletes, including luteal suppression or shortened luteal phase , anovulation, oligomenorrhea, primary amenorrhea, and secondary amenorrhea 2,33 . In contrast to disordered eating and bone strength, menstrual irregularities do not...
Etiology of Disordered Eating in Athletes
Most eating disorder experts agree that there is no single ''cause'' of eating disorders among athletes, but rather that the etiology is multifactorial and encompasses a complex interaction between sociocultural, demographic, environmental, biologic, psychological, and behavioral factors 28 . Controversy currently exists whether athletes are at a greater risk for developing eating disorders than their nonathletic counterparts some research suggests that the prevalence of disordered eating is...
Matthew S Ganio MS Douglas J Casa PhD ATC Lawrence E Armstrong PhD Carl M
Human Performance Laboratory, Department of Kinesiology, University of Connecticut, 2095 Hillside Road, U-1110, Storrs, CT 06269-1110, USA Studies related to fundamental hydration issues have required clinicians to re-examine certain practices and concepts. The ingestion of substances such as creatine, caffeine, and glycerol has been questioned in regards to safety and hydration status. Reports of overdrinking hyponatremia also have brought into question the practices of drinking appropriate...
Hyponatremia
Hyponatremia has received attention in the media as a result of its occurrence in popular road running races 28 . Hyponatremia is a serious complication of low plasma sodium levels lt 130 mEq L 29 . The exact cause is likely multi-faceted and circumstantial 30 . Hyponatremia has been observed in exercising individuals who became dehydrated 31,32 , maintained hydration 32 , and became overhydrated 31,32 . Asymptomatic hyponatremia is the most common type of hyponatremia 32 and is defined as a...
Methylsulfonylmethane
Methylsulfonylmethane MSM is another dietary supplement that is taken for the treatment of joint pain from arthritis. Its benefits for patients with osteoarthritis were investigated in a randomized, double-blind, placebo-controlled trial with 50 men and women 40-76 years old with pain from osteoarthritis of the knee who were enrolled in an outpatient medical center 75 . The patients received MSM 3 g or placebo twice each day 6 g d for 12 weeks. The outcomes included the Western Ontario and...
Dietary Reference Intakes
The Dietary Reference Intakes DRI for all known vitamins and essential minerals for healthy individuals living in the United States were updated between 1997 and 2005 4-8 . Adequate Intake AI , Recommended Dietary Allowance RDA , Estimated Average Requirement EAR , and Tolerable Upper Intake Level UL all are under the DRI heading. The RDA is the dietary intake level that is sufficient for approximately 98 of healthy individuals living in the United States. The AI is a projected value that is...
Chemical Maturity
If the principles and methods for estimating body composition are to be accurately applied to youth, including young athletes, it is important to determine when during growth are adult values for the primary components of FFM attained. When adult values are reached, chemical maturity is said to be attained. The concept of chemical maturity was introduced by Moulton 37 ''The point at which the concentration of water, proteins, and salts minerals becomes comparatively constant in the fat-free...
Caffeine
Caffeine and its related compounds, theophylline and theobromine, have long been recognized as diuretic molecules 14 , which encourage excretion of urine via increased blood flow to the kidneys 15 . The recommendation that caffeine be avoided by athletes because hydration status would be compromised 6 is based on several studies examining the acute effects of high levels gt 300 mg of caffeine 16 . More recent studies have tested the credibility of this recommendation by re-examining hydration...
Controversy
The argument has been made that regular exercise, particularly in elite athletes with highly demanding training regimens, increases protein requirements over those for sedentary individuals. This argument is often based on nitrogen balance. Several well-controlled studies have shown that nitrogen balance in athletes is greater than in inactive controls 1,3,4,19 . Increased protein needs may come from increased amino acid oxidation during exercise 20-23 or growth and repair of muscle tissue....
Importance Of Accurate Dietary Intake Assessment
Although this article focuses on micronutrients, a total evaluation of an athlete's energy intake is necessary because even if an athlete is consuming the correct amount of micronutrients especially if he or she is supplementing with a vitamin-mineral supplement , if energy requirements are not being met, athletic performance still would be suboptimal. Clark and colleagues 9 examined the preseason and postseason intakes of macronutrients and micronutrients in division I female soccer players....
Core Temperature And Hydration
Proper hydration is important for optimal sport performance 1 and may play a role in the prevention of heat illnesses 2 . Dehydration increases cardiovascular strain and increases core temperature Tc to levels higher than in a state of euhydration 3 . These increases, independently 4 and in combination 3,5 , impair performance and put an individual at risk for heat illness 6 . Exercise in the heat in which dehydration occurs before 3 or during exercise 7 results in Tc that is directly...
References 5
1 Clegg DO, Reda DJ, Harris CL, etal. Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis. N Engl J Med 2006 354 795-808. United States Senate Committee on Health E, Labor and Pensions, Subcommittee on Aging. Centers for Disease Control's role in combating the burden of arthritis. Washington, DC Department of Health and Human Services 2004. Cotran RS, Kumar V, Collins T, editors. Pathologic basis of disease. 6th edition. Philadelphia Saunders 1999....
References 2
1 Wang ZM, Pierson RN, Heymsfield SB. The five-level model a new approach to organizing body composition research. Am J Clin Nutr 1992 56 19-28. 2 Wang ZM, Shen W, Withers RT, etal. Multicomponent molecular-level models of body composition analysis. In Heymsfield SB, Lohman TG, Wang ZM, editors. Human body composition. 2nd edition. Champaign IL Human Kinetics 2005. p. 163-76. 3 Roche AF, Heymsfield SB, Lohman TG, editors. Human body composition. Champaign IL Human Kinetics 1996. 4 Heymsfield...
Kevin D Tipton PhD Oliver C Witard MSc
School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, Birmingham B29 5SA, United Kingdom Protein nutrition for athletes has long been a topic of interest. From the legendary Greek wrestler Milo purported to eat copious amounts of beef during his five successive Olympic titles to modern athletes consuming huge amounts of supplements, protein intake has been considered paramount. Recommendations for protein intake for athletes has not been without controversy, however. In...
Prevalence of Low Energy Availability and Disordered Eating in Athletes
To date, no published studies have examined the prevalence of low energy availability among female athletes. Such research likely would prove difficult to conduct because it would necessitate accurately assessing energy intake and exercise energy expenditure. The limitations inherent in self-reported energy intake eg, food records and energy expenditure eg, activity records are well documented 20 , and the expense or lack of generalizability involved in more direct measures eg, metabolic...