BODY WEIGHT AND ATHLETES Michael Turnbull 30 th October 2005

OVERVIEW Body size, build and composition play major roles in determining athletic success.

OVERVIEW Primary concern is an athlete’s fat mass and fat-free mass. The ideal body type varies with each sport. Athletes using diets to lose weight is common.

OVERVIEW Focus on: –Body composition and sports performance –The significance of fat-free mass and relative body fat –Achieving your optimal weight safely –Unrealistic weight loss and medical problems.

TECHNICAL TERMS Body Type: –3 different body types: ENDOMORPH ECTOMORPH MESOMORPH

TECHNICAL TERMS Somatotype: –Classification of the three body types

TECHNICAL TERMS Body Size: –Height and mass (weight) –Categorized as tall or short, large or small, heavy or light. Body Composition: –The body’s chemical composition. –Two components: fat mass and fat-free mass.

BODY COMPOSITION AND SPORTS PERFORMANCE Relative Body Fat: –Studies have shown that higher body fat %’s impair performance. Leaner athletes generally perform better. –Females generally have a higher percentage of body fat, this is thought to be a major reason between differences in performance. –This is confirmed in a study comparing m&f runners who, when matched by 24km times, did not differ in relative body fat.

BODY COMPOSITION AND SPORTS PERFORMANCE Fat Free Mass –Should be concerned with FFM rather than total body size or weight. –To increase FFM, combine resistance training with CHO and protein ingestion during the recovery – Stimulates release of anabolic hormones. –Triathlon is an endurance sport, a too high FFM is an additional load that must be carried and can impair your performance.

BODY COMPOSITION AND SPORTS PERFORMANCE How is performance impaired? –Metabolic cost of exercise is increased –Maximal oxygen uptake is reduced –Time to maximal fatigue is reduced –Lower threshold points

ACHIEVING OPTIMAL WEIGHT LOSS Decrease Fat Mass and increase FFM A healthy diet and regular exercise is key A 100kcal reduction per day can lead to a 4.5kg loss of body weight in 1 year. Couple this with a regular training plan total weight loss can be 10 – 16kg.

ACHIEVING OPTIMAL WEIGHT LOSS Guidelines: –Lose no more than 0.5kg – 1kg per week until reaching the upper end of desired weight range. –Then 0.5kg per week until goal weight is reached. –Extreme rapid weight losses result in a loss of FFM –Recommended weight loss can be accomplished by reducing dietary intake by kcal per day when combined with a sound exercise program.

ACHIEVING OPTIMAL WEIGHT LOSS Bad Dieting: –Severe (very low calorie) diets lead to weight loss via water, not fat. Fad Diets (EG: Atkin’s) –Severe diets also limit CHO intake, thus depleting CHO stores. –Water is lost with CHO, exacerbating dehydration –Increased reliance free fatty acids can lead to ketosis (acidosis of the blood caused by production of Ketone bodies), again increasing water loss.

RISKS WITH SEVERE WEIGHT LOSS Dehydration Chronic Fatigue Eating Disorders Menstrual Dysfunction Bone Mineral Disorders

CONCLUSION Optimizing body composition can enhance your sports performance Fat-free mass and relative body mass can affect your sports performance In order to lose fat/weight, avoid crash and fad diets Resistance training promotes fat free mass For fat loss, moderate resistance and endurance training is most effective.