8+9. adaptations Flashcards Preview

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Flashcards in 8+9. adaptations Deck (36):
1

adipose tissue adaptation to exercise

increased mitochondrial content
- same effect across different adipose tissue deposits

2

markers for mitochondrial content in adipose tissue

COXIV protein content
citrate synthase activity

3

liver adaptation to exercise
- markers

increased mitochondrial content

markers of this
- cytochrome C content

4

skeletal muscle adaptation
- obese indv
- 8 weeks
- moderate intensity endurance training
- biopsies

increased
- CPT1 activity
- mitochondrial FA oxidation

5

CPT-1 role

rate limiting step in FA oxidation

6

effect of activation AMPK

induces GLUT4 and mitochondrial biogenesis

- protein phosphorylation

7

effects of HIIT/SIT (sprint interval training) (4)

improves "aerobic" performance
increase mitochondrial enzymes and biogenesis
increase resting glycogen content
increase muscle FA transporters (total GLUT4)

8

function of citrate synthase

initial enzyme in TCA cycle
- catalyzes acetyl CoA + oxaloacetate = citric acid

9

HIIT training benefits/negatives

benefits
- improvement seen in 2 weeks
- less time commitment

negatives
- concern with heart patients
- some not enough motivation/skill to perform
- not as many calories burned

10

time to fatigue associated with
- 2 ways to prevent this

initial muscle glycogen

1. increase muscle glycogen stores
2. increase muscle ability to oxidize other substrates

11

glycogen supercomposition

deplete glycogen over a few days with intense exercise, then increase carb intake after

** must deplete first for supercomposition to occur

12

traditional carb loading technique
(Astrand)

- exhaustive exercise 7 days before event
- low carb for 3 days following (increases glycogen synthase activity)
- high carb remaining days with minimal training

13

problems with traditional (Astrand) carbohydrate loading

1. training difficult with low carb intake
2. irritable
3. muscle weakness and disorientation
4. exhaustive exercise at beginning have little training effect and can impair muscle glycogen resynthesis

14

Sherman method of carb loading in comparison to tradition astrand method

more gradual
- limit training 1 week before
- normal diet first 3 days (55% kcal from carb)
- high carb last 4 days (70% carb)

*same muscle glycogen
*better rested

15

why see weight gain with carb loading

glycogen stores 2.6 grams of water per 1 gram

16

benefits of high fat, low carb diets

increase capacity for fat oxidation
- increase citrate synthase (CS)
- increase B-hydroxyacyl dehydrogenase
*indicators of mitochondrial content

increase exercise performace
** previously untrained individuals

17

why untrained benefit from low carb / high fat while trained do not

untrained
- additional stress of low carb
- more endurance gains faster

trained
- high carb able to train harder

18

carb intake during exercise
- aerobic exercise effects

increase time to exhaustion 30%
- above normal and maintained plasma glucose levels

19

glycogen resynthesis after exercise

window = 30min to 2hr

4hr post exercise, glycogen synthesis reduced to 50% of capacity compared to right after exercise
- additive effects of insulin
- consume carbs immediately after workout***

20

effects of high fat diets on exercise performance (trained individuals)
- >45% kcal from fat

- enhances fat oxidation
- increases mitochondrial enzyme activity
- slight reduction in glycogen utilization
- no performance benefit (endurance events)

21

effects of caffiene on performance

"postulated" increase in fat oxidation and improve endurance performance

*unclear

22

travel path of caffeine

- quickly enters blood
- crosses all body membranes (including blood brain barrier)

23

half life of caffeine

4-5hr

24

how much caffeine is used

5-9mg/kg body mass

ex. 6mg/kg x 70kg = 420mg of caffeine

25

amount of caffeine in drinks

coffee 16oz grande
- 330mg

redbull 250mL (8oz)
- 80mg

26

original theory to caffeine mechanism of action
- T or F?

stimulates epinephrine release
- increase FFA's release from adipose
- increase fat oxidation
- spare glycogen, improve endurance

*NOT TRUE*
- when tested, no change in VO2 max, RER or muscle glycogen content

27

effects of caffiene on exercise

large increase in time to exhaustion

ex. 85% VO2max

28

recent evidence of the mechanism of caffeine enhances performance

central nervous system
- crosses all membrances including blood brain barrier
- increases arousal, wakefulness, alertnes, vigilance and mood

antagonist to "adenosine"
- binds and blocks adenosine receptors
- adenosine is an inhibitory neurotransmitter
- suppresses arousal and spontaneous activity

29

caffeine on high power output aerobic performance (20-30 min at 85% VO2max)
- central vs peripheral

large benefit (most studies)
- likely central, not peripheral effect

30

caffeine on intense exercise (4-8min)
- central vs peripheral

central and peripheral benefits
- ion Ca 2+ handling?

31

caffeine on sprint exercise
- central vs peripheral

no benefit
- purely anaerobic
- single and multiple sprints

32

side effects of caffeine

anxiety
jitters
insomnia
inability to focus
GI upset
irritability
etc

33

amount of caffeine on side effects

mild effects
- >6mg/kg body mass

minimal effects
- 3-6mg/kg body mass

*highly variable between individuals

34

active component of beet root juice

Nitrate (approx 400mg per shot)
- becomes Nitric Oxide

35

physiological benefit of beet root juice

NO2 = vasodilator
- more blood + oxygen to muscles
- lower oxygen needed

36

beet root juice experiment
- benefits on exercise

improved time-trial performance and power output
- at multiple power outputs
- O2 consumption lower

** signifcant benefits not seen in elite runners
- genetic variation
- elite runners have higher nitric oxide precursor levels