EP- Body composition Flashcards
Define body composition
the distribution of lean body mass and body fat mass
Define fat mass
the percentage of body weight that is stored fat
Define lean body mass
the weight of the rest of the body – muscle, bone, connective tissue, and organs.
What are the average body fat % for men (non-athletes)
12-18%
What are the average body fat % for men (athletes)
6-12%
What are the average body fat % for women (non-athletes)
22-28%
What are the average body fat % for women (athletes)
12-20%
Why are athletes typically heavier than average people
Because muscle weighs more than fat
Give the 5 body composition assessments
- BMI
- Hydrostatic weighing
- BIS
- Bodpod
- Skinfold callipers
What does BMI measure
measures an adult’s weight in relation to their height.
Their weight is divided by their height in metres squared
What is an acceptable BMI range for men and women
- 1 - 25 (men)
18. 5 - 24.8 (women)
What BMI number indicates someone may be obese
30+
Give 2 disadvantages of BMI
- BMI does not directly measure body fat.
- Not suitable for young children, pregnant women, the elderly, or athletes.
- Athletes higher proportion of muscle pushes them outside the normal range, despite their body fat being well within normal the range.
Why do we continue to use BMI
It has become the medical standard used worldwide and does have some value if you’re a standard adult.
Give the method for hydrostatic weighing
- Athlete is weighed on land
- Athlete is weighed totally immersed in water.
- The difference between the athletes ‘dry’ weight and the underwater weight indicates the athlete’s fat percentage.
- Fat floats – so the greater the body fat, the bigger the difference between the two weights.
Give an advantage for hydrostatic weighing
Most accepted and accurate measure of body composition.
Give 2 disadvantages for hydrostatic weighing
- Only an estimate of the density of fat-free mass- this varies from gender, age and race (not totally accurate).
- Not readily available to most people.
- Expensive
What does BIS stand for
Bioelectrical Impedance Spectroscopy
How does BIS work
- BIS scales send a safe, low electrical current through the body
- The current flows easily through the fluids contained within muscle tissue but fat impedes the flow of the current
- Having programmed in the athletes’ height and weight, the scales work out the body fat percentage.
Give an advantage of BIS
Accurate
Safe
Can be easily tracked over time
Give a disadvantage of BIS
- Affected by the hydration level of the performer (as it relies on the fluid levels of the fat-free tissue such as muscle).
- Uses average population fat-free tissue values to work out fat percentage– so not suitable for athletes.
- A number of factors can affect the accuracy of the test: Eating habits/alcohol consump-tion/exercise/time of day
Describe the method for skinfold callipers
- Skinfold callipers measures (in mm) subcutaneous fat (below the skin) from a number of sites on the body.
- The sum of the measurements is used to estimate body fat percentage.
- A number of tests are available, using different parts of the body (gender specific)
Give 2 advantages of skinfold callipers
- Most widely used method of assessment.
- Accessible, cheap and practical to use.
- Provide a good estimate of body fat percentage (multiple site/gender specific tests)
Give a disadvantage of using skinfold callipers
Testers need training, to ensure the specific sites are measured accurately
Give the method for BodPod
- Fitted clothing is worn and hair under a swimming cap
- Weight of subject is measured
- Bodpod is calibrated
- Subject sits inside twice for 50 secs
- Test results printed from the computer
Give 2 advantages of using bodpod
- Accurate
* Suitable for children
Give 2 disadvantage of using bodpod
- Expensive
* Difficult to access
What are the two sections to the energy balance
- Energy intake – food
* Energy expenditure – work/physical activity
What happens if energy intake exceeds energy expenditure
the excess is stored as fat
What happens if energy expenditure exceeds energy intake
weight will be lost in the form of fat
Define BMR
the lowest rate of energy expenditure to sustain the body’s essential physiological functions at rest
What’s the difference between BMR and RMR
RMR takes away the need to measure sleep
What is the thermic effect used to describe
the energy used in eating, digesting, absorbing and using food
What does MET stand for
Metabolic Equivalent Task
What are METs
the ratio of the activities working metabolic rate relative to the resting metabolic rate
Give 2 examples of METs
the resting metabolic rate is given a value of 1.
Slow walking on the flat would have a value of 2 METs.
Running at 6mph (10 min miles) has a value of 10 METs.
Define energy intake
The food we eat
What does a balanced diet consist of
- 10-15% protein
- No more than 30% fat
- 55-60% carbohydrates
- Vitamins, minerals, fibre and water.
Give 4 health implications of being overweight
- Increased risk of diabetes (particularly type 2).
- Increased risk of cancers.
- Increased risk of heart disease, deep vein thrombosis (DVT), stroke (resulting from long term stress on the CV system).
- Overloading joints impacting on posture and alignment – leads to musculo-skeletal pain.
- Psychological harm of stigma, bullying and low self-esteem.
- Low self-esteem leading to social difficulties.
- Under performance in physical and mental work.
Give 3 implications of being overweight for sport
- Overweight/obese performers will have an increased energy expenditure for a given activity than those whom are not.
- There is a greater load on the joints and risk of injury (through greater wear and tear or acute force trauma).
- Decrease in joint mobility/flexibility.
- Decrease in economy of movement.
- Decrease in fatigue resistance.
- Negative cycle – overweight/obese individuals have a negative view of physical activity.
- They are unlikely to take part due to the associated stigma of being overweight/obese - worry about how they are perceived by others.
What exercise intensity is needed for fat loss
- Duration should be at least 20-30 mins to allow the metabolism of fats.
- For optimum fat burning, exercise intensity should be lower.
- This encourages the usage of fats for energy instead of carbohydrates (glycogen/glucose)
