what is bioenergetics?
- Study of energy transformation in living organisms
- convert food into a biologically useful forms
of energy
what is _________ work
1. mechanical
2. chemical
3. electrical
4. transportation
1.force production by skeletal muscle
- glycogen synthesis for energy storage
- protein synthesis - pumping ions to maintain voltage gradients across
membranes - circulation of gases & nutrients to tissues via blood
what is potential energy?
- this is stored energy
- endergonic reaction & proceeds.
what is kinetic energy?
- this is energy that is used.
- it is a exergonic reaction & process because energy is being used.
what is a direct calorimetry?
- direct measurement of heat energy
- useful in measuring pure substances
what happens with oxidation and energy (kcal)?
- every time oxidation occurs from after hydrocarbon, their is a loss in the energy of kcals.
how are dierct and indirect calorimetry measured?
DIRECT
- can be done for humans by directly measuring
temperature change in surroundings
– precise & accurate but technically difficult
– usually done for research only
INDIRECT
based on measurement of gas exchange
– Increases in O2 consumption and/or CO2 production are
proportional to increases in aerobic energy use
what is total energy expenditure?
- The sum of all energy required in a 24 hr period
what does TEE consist of?
- Resting metabolism 66%
- Thermic effect of food 10%
- Physical activity 25%
what is basal metabolic rate?
- This is the minimum amount of energy needed to keep the body alive during complete rest.
what is rest metabolic rate?
- The amount of energy required by the body to maintain a non-active, but alert state.
- Also known a resting energy expenditure
what Influences on RMR, not under voluntary control?
- Sex
- Age
- RMR decreases 1-2% each decade - Body
- Greater surface area = more heat loss= higher RMR - Hormones
- High thyroid hormone = high RMR - Genetics
what Influences on RMR, under partial voluntary control?
- Fat free mass
- Higher FFM = higher RMR
- Resistance training to increase lean mass
- Endurance training to increase energy expenditure - Self- restricted food intake
- Body adapts to starving within 48 hr
- RMR can reduce by 20% to protect lean tissue and fat
what Influences on RMR, under voluntary control?
- Temperature
- RMR increases in cooler climate - Altitude
- RMR increases at higher altitude - Caffeine & nicotine
- Increase RMR by 3-7% for 1-2 hr - Recent physical activity
- RMR increase after activity for 10-90 minutes
advantages and disadvantages of MSJ equation?
+ has factor for age
+ suitable for healthy sedanctary indiviudals
- Underestimate RMR of athletes
RMR = (9.99 x wt) + (6.25 x ht) – (4.92 x age) +/- (sex term)
advantages and disadvantages of Cunningham equation?
+ more appropriate for athletes
+ better for more lean individuals
- Requires estimate of body composition
- No age term
- RMR (kcal/day) = 500 +(22 x FFM)
- FFM = (total mass) – (total mass X %BF)
what is thermic effect on food?
- Energy that must be expended to digest and absorb food.
how does physical activity and TEE work together?
- All activity increases TEE above RMR
- Exercise increases TEE
- Elite endurance athlete can expand TEE upto 50% during competiton
what is a MET?
- Metabolic rate X intensity of physical activity
- Calculate RMR (kcal/h)
- Find MET level for activity
- (MET) X (RMR) X (TIME) = kcal expended
