Exam 3 - chantel2 Flashcards
What is Fitness?
ability to perform routine physical activity w/o undue fatigue
How does exercise improve fitness?
Body will adapt to stresses placed on it (overload principl)
>Body won’t build mscl unless stress is put on it
»>Protein powder alone will not lead to mscl gain
What is aerobic exercise?
exercise that increases HR and requires O2 in metabolism
>Endurance exercises–jogging, swimming, cycling
>Uses cardiorespiratory system–delivers O2 and nutrients to cells
How does regular aerobic exercise help the cardiovascular and respiratory systems?
increases cardiorespiratiory endurance bc it
>Strengthens heart muscle
>Increases stroke volume (how much blood can be pushed out of heart w/ each stroke)
>Decreases resting HR
What is hypertrophy?
increase in muscle size and strength due to stress or overload during exercise
What is atrophy?
decrease in size and strength of mscl due to lack of use, e.g. when you break a bone are are casted
How do weight loss and weight maintenance compare in terms of exercise? Muscle vs fat?
> Need a lot more exercise to lose weight than to keep weight off
Greater proportion of muscle v fat (energy use)
»Individuals who are physically fit have a greater proportion of lean body tissue than unfit individuals of same body weight
Body composition, % of fat vs non-fat or lean tissue, is an indicator of health and fitness
What are effects of long-term exercise on weight? Role of physical activity in weight management?
*Lower set pt by increasing use of lipid for energy
»>Body now defends a lower weight
*Physical activity is critical for weight management – you will NOT keep weight off unless you exercise
Benefits of aerobic exercise on heart (cardiovascular health)?
Strengthens heart mscl, thereby decreasing BP and reducing risk of CVD
>Prevention of recurrence of heart disease
Effects of genetics and exercise on HDL levels?
Genetics-higher HDL bc use of fasting TG for energy
Exercise-does not increase HDL very much
How does exercise affect diabetes onset?
Prevention or management
>Prevents weight gain, which turns on type 2 gene
>Moves glucose into cell, despite insulin resistance
How does exercise affect bones?
Weight bearing exercise strengthens bone, decreases risk of osteoporosis
(Weight-bearing exercise can increase peak bone mass and prevent bone loss.)
How does exercise affect cancer risk?
can reduce risk by as much as 40%
How does exercise affect psychological health?
improves mood,
boosts self-esteem,
increases overall well-being,
**reduces stress
What is aerobic zone?
an activity is in aerobic zone if it raises HR to 60-85% of max HR
(max HR = 220-age)
What is ANaerobic metabolism?
short-term energy, absence of O2
>Full capacity at 30s after start
>Only glucose: end at 2 pyruvates + 2 ATP
>Used when O2 can’t be supplied quickly enough to tissues to support aerobic metabolism
What is aerobic metabolism?
O2 is used, exercising while able to carry a conversation
>Full capacity after 2 to 3 mins
>Can completely catabolize glucose, fatty acids and AAs
>Slower process but much more energy released bc you take advantage of other cycles
**Glucose = glycolysis
**Fatty acids = beta oxidation
**AAs = deamination, then TCA cycle
>Electron transport is final pathway: form CO2 and H2O to produce ATP
What happens when you haven’t eaten and you exercise?
You use LIPIDS!!
>Low insulin lvls
>Insulin blocks hormone sensitive lipase (HSL) at the adipose
»>HSL=enzyme that lets fat out of fat cell
»>If there’s low insulin, you get fat into blood bc HSL is unblocked
> Low/moderate intensity exercise, as you need to get sufficient O2 into blood for beta oxidation
»Use lipid for energy after 20-30 mins
When do you use protein for energy? Cons?
> End of endurance exercise if insufficient glucose
*You use fxnal protein—(lose skeletal mscl)
How does exercise intensity affect energy use?
> High intensity = more glucose (more anaerobic metabolism)
Lower intensity = enough O2 to mscls so can use both glucose and fatty acids—more aerobic metabolism
Intensity is individual/relative
Training decreases time to “use of lipid for energy”
What is VO2 (volume of o2) max?
Max volume of O2 consumed per unit time (usually mins)
>Varies by individual
>Can use to measure intensity
>Can increase w/ training
When does fatigue occur? Why?
?????
> At high intensity
> Depletion of glycogen (glucose)
Anaerobic: glycolysis → 2 pyruvates + NADH
Decrease in NAD (needed for glycolysis to continue)
Pyruvate + NADH → lactic acid + NAD
**Make lactic acid so glycolysis can continue when there’s no O2
How does training affect use of fat for energy?
> Decreases time to beta oxidation
>Increases size and # of mitochondria in mscl (so more O2 is present at any given time)
