BODY COMPOSITION

W HAT 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

A VERAGE PERCENTAGE FAT MASS SportMale %Female % Baseball Basketball Cycling Field Hockey Rowing Swimming Track – Runner Track – Jumper Track – Thrower Triathlon Volleyball

S IZE 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

B ODY 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

B ODY 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

B ODY 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

S KINFOLD C ALLIPERS SITEMETHODPICTURE TRICEP Take a vertical skinfold parallel to upper arm, halfway between the shoulder and the elbow SUBSCAPULA Take a diagonal skinfold across the back, just below the shoulder blade BICEP Take a vertical skinfold halfway between the elbow and the top of the shoulder on the front of the upper arm SUPRAILIAC Take a diagonal skinfold along the line of the iliac crest just above the hip bone

B ODY MASS INDEX ( BMI ) Measure of weight against height Weight in Kg’s / Height in Metres Squared Men range Women range 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 S CALE Below 18.5 Underweight Normal Overweight 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!

E NERGY 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

A N AVERAGE DAY 60-75% is RMR 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) protein No more than 30 fat Carbohydrate

C ALORIE I NTAKE 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

H EALTH IMPLICATIONS Diabetes Cancer Cardio-vascular disease Joint stress psychological harm Under performance

I NFO FOR EXTENDED QUESTIONS Huge increase in past 10 years Britons amongst heaviest in Europe By % 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

E FFECTS 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