220 likes | 865 Views
BODY COMPOSITION. What is body composition?. How the body is made up. Split into 2 components. Fat mass refers to a persons percentage of body weight stored as fat (within adipose tissue) Lean body mass , weight of the rest of the body (bones, muscles, organs, tissue )
E N D
What is body composition? How the body is made up. Split into 2 components. • Fat mass refers to a persons percentage of body weight stored as fat (within adipose tissue) • Lean body mass, weight of the rest of the body (bones, muscles, organs, tissue) • Height and weight are not always a good indicator of body composition
Size in relation to sport • Every sport has an ideal size for their requirement e.g. Compare high jump to sumo what are the needs of the competitors? • Weight is not that important its body composition that an athlete will be concerned about • Muscles weighs around 3 times more than fat so being heavier may not be a detriment
Body mass assessment Hydrostatic Weighing • Athlete submerged in water • Difference between dry and wet weight gives percentage fat • Fat is less dense and floats in water • Most common and accepted method • Most accurate but least available method • Only estimated density of fat which varies to age, gender, race
Body mass assessment Bioelectrical Impendence Spectroscopy (BSI) • Low safe electrical current passed through body on body fat scales • Fat gives resistance to current (impedance) • Results set against height and weight chart, scales then give % fat • Measurement is affected by hydration • It uses estimates of population so not appropriate for elite athletes with more lean muscles tissue
Body mass assessment Skinfold measurement • Skinfold callipers measure in mm the level of fat below skin from selected body sites • Sum of these measurements estimates fat % • Locations vary but usually, tricep, bicep, subscapular and suprailliac • Most widely used as cheap • Lots of measurements so accurate • Testers need to be trained and measure specific sites
Body mass index (bmi) • Measure of weight against height • Weight in Kg’s / Height in Metres Squared • Men range 20.1-25.0 Women range 18.5-23.8 • Does not directly measure fat but is correlated to body composition • Better estimate to overweight/obesity than other methods • Not suitable, for young, elderly, pregnant or athletes • Athletes heavy muscles mean this is disproportionate • Used a government standard test for health
BMI Scale • Below 18.5 Underweight • 18.5-24.9 Normal • 25-29.9 Overweight • 30-34.9 Obese • 35+ Very obese • Calculate this BMI • Weight 124 KGs Height 1.96 m 1.96 x 1.96 = 3.84 m2 124 / 3.84 = 32.3 BMI JONAH LOMU
OVERWEIGHT AND OBESITY • Occur as a result of an imbalance between energy intake and energy expenditure • If energy intake is greater than expenditure weight will increase • However increasing muscle mass will also will also increase weight!
Energy expenditure Basal Metabolic Rate (BMR) • The lowest amount of energy required for minimum energy expenditure at normal rest levels (after 8hrs sleep and 12 hrs fasting) Resting Metabolic Rate (RMR) • Does not include the measure of sleep so is generally used more frequently
An average day • 60-75% is RMR • 20-30 Physical activity • Rest energy used when eating, absorbing and digesting food (thermic effect) • Add all 3 to get Body's Total Metabolic Rate
ENEGY INTAKE • On average men 2550 calories, women 1940 per day. • Varies depending on? • Lifestyle, age, height, weight, activity, body composition. • A balanced diet looks like this (%’s) • 10-15 protein • No more than 30 fat • 55-60 Carbohydrate
Calorie Intake • Obviously the balance between energy intake and energy expenditure determines your total body weight • Balance of the 5 a day? Find these out • Depending on your diet calories can come from proportionally the 3 energy fuels, carbs, fats, proteins
Health implications • Diabetes • Cancer • Cardio-vascular disease • Joint stress • psychological harm • Under performance
Info for extended questions • Huge increase in past 10 years • Britons amongst heaviest in Europe • By 2050 60% men, 50% women clinically obese • Only 5% of children walk to school 80% 20 years ago • Cost of obesity to UK society by 2050 £50 Billion • Obesity causes 18 sick days per year
Effects of phys act. on body comp • Increase activity means increased number of calories burned • Increased calorie burn even when activity has stopped post-exercise • Increases lean body tissue which burns more calories • Exercise increases the mobilisation of fats as energy fuel • Therefore increase RMR when even at rest