3: Body Composition Flashcards
What is body composition?
the body’s relative amounts of fat mass and fat free mass (bone, water, muscle, CT, organ tissues, and teeth)
What is somatotyping?
the human body is composed of:
- roundness
- muscularity
- linearity
- various sports require sport-specific body types for achieving optimal performance
What are endomorphs?
exhibit a round appearance and predominance of the gut and visceral organs
- common sports: wrestling, weihgt lfiting and throwing events
What are mesomorphs?
exhibit predominance muscle
- common sport: body building, swimming, decathlon
What ectomorphs?
predominance of linearity and tend to be tall and thin
common sports: marathon, basketball, horse racing, high jumps
What is Body mass index?
a measure of relative body weight correlating highly with more direct measures of body fat
How do you calculate BMI?
dividing the weight in kg by square of the height (metres)
Kg/m^2
What are the four categories of BMI
underweight (BMI < 18.5)
Normal eight (BMI 18.5 to 24.9)
overweight (BMI 25 to 24.9)
obese (BMI> 30)
What are the components of body compositions?
fat componenet (% BF) non-fat component (lean body mass)
What are absolute measurements?
kg, cm, 1/min
What are relative measurements?
%, x/kg, ml/kg/min
What are essential fat?
needed for normal physiologic function
- found within tissues such as muscles, nerve cells, bone marrow, intestines, heart liver and lungs
- about 3% of total weight in men, 12% in women
what are storage fat?
stored in adipose, mostly subcutaneous insulator to retain heat energy substrate for metabolism padding against trauma men= 12% = stored around weight women = 15% = stored in hips/thighs
What is overweight?
total body weight above a recommended range for good health
what is obesity?
over-fat; characterized by excessive accumulation of body fat; excess of body fat beyond some particular standard
carb loading
the longer you can spare your glycogen stores, the longer you can go
what are factors contributing to excess body fat?
- people underestimate portion sizes
- eating - compared to the past, americans consume more calories, more refined and simple CHO and eat out more often
- the environment
- PA declined
- Psychosocial factors include eating as a means of coping and cultural and family influences
What is glycogen
polysaccharide
full of glucose
What is creeping obesity?
obese individuals are often viewed as gluttonous, they generally do not consume large amounts of Kcal. Physically ative individuals shown to consume more kcal than obese idnviduals.
obesity is often the result of too little activity rather than over eating
result: of long term change in energy balance that results in gradual fat gain over a period of time
What are health implications fo overweight and obesity?
33% rise in type 2 diabetes,
400,000 premature deaths annually
- obesity is one of the 6 major controllable risk factors for heart disease
other health problems: coronary heart disease, stroke, hypertension, osteoarthritis, some cancer
weight loss of 5-10% in obese individuals can reduce the risk of certain disease
measuring body fat
skin fold calipers hydrostatic weighing body pod bioelectrical impedance DEXA
Skinfold thickness
several sites measured, should be taken on the right side
men: chest, abdomen, thigh
women: triceps, suprailium, tight
Hydrostatic Weighting
Calculate body fat, the following measurements are needed:
- body weight on land
- underweight body weight
- water density at the performed temperature
- residual lung volume
compare regular weight with under water weight
fat is more buoyant to get percent of fat
drawbacks: slow process, lung capacity, aquaphobic people
The bod pod- air displacmeent
utilizes sensors accuracy; air displacement and body volume
body density and percent body fat then determined
easy to use speed
not readily available - cost
efficacy in different populations to be determined size accommodations
Bioelectrical Impedance Analysis (BIA)
flow of electricity thorugh tissue/fat
related to level of body fat
influenced by hydration state
cost and accurarcy
Dural energy x-ray absorptiometry (DEXA)
used most frequently in medical facilities and research
very low dose x-ray
not readily available
measures: total body fat; fat distribution; bone density
Were is the energy in your body?
in triglycerides but theres a lot of water that comes along with that
What happens when energy intake = ouput
no change in body mass
How do you increase body mass related to energy balance equation
increase intake
how do you decrease body mass?
increase output
What are the components of total energy expenditure?
physical acitvity+ thermic effect of exercise (TEE) + thermic effect of food (TEF)+ resting metabolism (REE) = total energy expenditure
What is basal metabolic rate?
a measure of the amoutn of energy per unit of tiem enxessary to keep the body alive at compelte rest.
what is RMR?
resting metabolic rate
the amount of E required by the maintain a non-active, but later state
how many kcals is burned in 1 litre of 02 consumed?
5 kcal
What are genetic facotrs affecting REE?
- amount of metabolically active tissue possessed
- age
- sex
- natural hormonal activity
- body size and surface area
- body composition
What are the effects of body composition on REE?
- loading body weight generally lowers REE
- very low-calorie diets may significantly decrease the REE in obese individuals by lowering levels of thyroid hormones
- maintaining normal weight while reducing body fat and increasing muscle mass may raise the REE
the decline in the REE associated with aging may be partially due to…?
- physical inactivity
- muscle tissue loss (sarcopenia)
- accumulation of body fat
Environmental factors and REE
a. caffeine raises REE
b. smoking cigarettes raises REE
c. Climatic conditions that may raise REE
(heat;cold;altitude exposure)
Thermic effect of exercise (TEE) has a role in total daily E expenditure
a. REE 60-75%
b. TEF 5 - 10%
c. TEE = 15-30%
thermic effect of food (TEF)
what is it
energy required for the digestion and absorption of food
estimated to be 10% of total caloric intake for the day
proteins increase TEF more than CHO
effect of TEF on RMR is very small
Thermic effect of food (TEF)
a. highest about one hour after meal and lasts for about 4 hours
b. the greater the caloric content of the meal, the greater the effect
c. protein (25%), alcohol (15%) and CHO (8%) significantly increase the TEF whereas the effect of fat (3%) is minimal
d. increase REE about 8 - 10% percent from mixed meal
e. Accounts for approx 5-10 percent of total daily energy expenditure
f. studies report the TEF is significantly higher in lean subjects compare to obese
Physical Activity
any kind of PA requires energy expenditure above resting
increased by voluntary physical activities
can be influenced most readily and to be largest extend, the most variable
modifies resting metabolism!
Most important factor affecting TEE is intensity of exercise
- efficiency of mvt will affect caloric expenditure
- increases in air or water resistance increase caloric expenditure exponentially
- the heavier the load, the greater the caloric cost.
Two key determinants of Total energy expenditure: intensity and duration
Choose activities that use large muscle groups and are performed continuously
Walking
(1) Slow walking uses one-half the number of calories per mile as running
(2) Walk at a vigorous pace energy expenditure
(3) Climbing stairs makes walking more vigorous
(4) At given walking speed, hand weights will energy expenditure
Other aerobic activities and Energy expenditure
- Swimming a given distance takes about four times as much energy as running
- Bicycling costs one-third the energy to cover a given distance compared to running
- Running costs 1 C/kg/kilometer or 0.73 C/lb/mile
- In-line skating at twice the speed of running would use about the same Calories per mile
- Low-impact aerobic dance may use 9-10 C/min and is less likely to induce injuries to the legs
physical activity INCREASES muscle
- functional tissue!
- more active metabolically than adipose tissue-protein synthesis requires energy (to build and to maintain)
- emphasized when weight loss plateaus
- does not occur with dieting (opposite may occur)
1 lb uses ____ kcal per day?
35 kcal
What is the best way to increase muscle?
a combination of diet and exercise
lifestyle should focus on what to make changing in body composition
–Regular physical activity, endurance exercise, and strength training
–Moderate energy intake
–Physical activity is the key to long-term success
