Applied Exercise Physiology Study Guide for body composition and heart disease risk Final exam date December 13 7 30am Chapters 28 body composition Chapter 30 exercise and weight control 1 Know and understand the principle of Archimedes and how it applies to the procedure of human body volume measurements The principle of Archimedes principle is based on specific gravity or body density It measures whole body density using the ratio of body mass to body volume Buoyant force an object s loss of weight in the water the weight of the volume of water that it displaces its specific gravity refers to the mass of an object in air divided by its loss of weight in the water This applies to the procedure of human body volume measurements because it is relating to the indirect measurement of hydrostatic weighing This is considered the gold standard for measurements being the most accurate when measuring body fat percentages Specific gravity weight of air loss of weight in water weight in air weight in water Measuring body fat percentage Siri equation 495 body density 450 2 Understand the differences and usefulness of different body composition and anthropometric assessment procedures discussed in the text and class What are the general assumptions used by indirect measures Body composition techniques Direct High accuracy Indirect Anthropometrics Hydrostatic weighing Bod Pod Dexa and BIA Anthropometric measurements an indirect measurement refers to using height weight circumferences and skinfolds to estimate the body s composition Standardized techniques eg Calipers tapes to quantify body size proportion and shape General assumptions for indirect measures not as accurate as direct measurements there is more room for error 3 What are the body composition differences between males and females Body comp evaluates the structural constituents of body muscle bone and fat expressed as the relative percentage of body that is fat and fat free tissue Males Avg 15 range 10 to 22 Overweight above 20 Females Avg 26 range 20 to 32 Overweight above 30 4 Understand the difference between essential and storage fat and the difference between FFM and LBM Essential fat consists of the fat in the heart lungs liver spleen kidneys intestines muscles and lipid rich tissues of the CNS and bone marrow sex specific fat o Gender Specific Fat Women have gender specific fat in the mammary tissue pelvic buttock and thigh regions Due to this necessary gender specific fat women have a larger of essential fat than men 10 13 vs 2 5 Hormonal differences may be a cause of extra essential fat needed for women compared with men Storage fat fat primarily in adipose tissue Adipose tissue energy reserve contains approx 83 pure fat 2 protein and 15 water Storage fat includes the visceral fatty tissues that protect the organs within the thoracic and ab cavities from trauma and the larger adipose tissue volume deposited beneath the skins surface o Subcutaneous Fat o Visceral Fat Fatty tissue directly under skin Fatty tissue amongst the visceral tissue organs FFM Fat free body mass represents the body mass of all extractable fat body mass fat mass LBM Lean body mass contains the small percentage of non sex specific essential fat equal to approx 3 of body mass 5 How does energy balance and weight loss affect body composition Energy balance refers to the amount of energy in vs the amount of energy out which is a direct measurement of weight change Energy input is the amount of protein lipids and carbohydrates consumed which leads to weight gain Energy output is the TEF thermic effect of food amount of physical activity and resting metabolism that leads to weight gain If you are having an equal amount of energy in and out then there will be no weight change More energy in than out will lead to weight gain and more energy out than in will lead to weight loss Weight change total energy intake total energy expenditure 6 Understand the potential impact of diet and exercise on obesity e g what are the differences of dieting alone as compared to dieting and exercise combined Body weight loss there is an equal amount of weight loss between only dieting and only exercising but combining diet and exercise together yields a slight increase in weight loss Body fat loss there is an equal amount of fat loss when comparing exercise alone and diet and exercise together but when dieting alone there is not as much fat loss Lean tissue gain exercise alone yields the most lean tissue gain Diet and exercise combined yields less than half the amount of lean tissue gain compared to exercise alone Diet alone leads to drastic lean tissue loss 7 Understand the concept of the energy balance equations Energy in Food Refer to 5 Energy out BMR TEM ACTIVITY 8 Know the changes that occur in fat cells during weight gain and weight loss Comparing obese vs non obese people obese people will only have more than double the amount of body weight and total fat but they will have a much larger cell size and cell number more than twice as much Because there is a reduction in the size of the fat cells but the number does not change it is suggested that hypertrophic individuals have a better chance of beating obesity During weight gain Adipose tissue can mass increase in 2 ways Fat cell hypertrophy fat cell hyperplasia There is an increase in both cell size and cell number but a much higher increase in fat cell numbers than size During weight loss Adipose cellularity size and body weight will decrease over time but number of cells will stay the same throughout weight loss 9 What is BMI What is the relationship of BMI to disease BMI stands for body mass index BMI body mass kg stature m 2 BMI is related to disease because a higher BMI leads to a higher risk of disease Body fat is associated with hypertension type 2 diabetes stroke heart disease and hyperlipidemia Classification of BMI underweight 18 5 kg m 2 normal 18 5 24 9 kg m 2 overweight 25 29 9 kg m 2 obese class 1 30 34 9 kg m 2 class 2 35 39 9 kg m 2 class 3 40 kg m 2 10 What are the common techniques used to assess body composition There are indirect and direct measurements to assess body composition Direct more accurate method although expensive Indirect Anthropometrics refers to using height weight circumferences and skinfolds to estimate the body s composition Hydrostatic weighing densitometry or UWW gold standard measures using specific gravity or body density DEXA dual energy X ray absorptiometry Bioelectrical
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