8+9. adaptations

Question 1

adipose tissue adaptation to exercise

Answer 1

increased mitochondrial content

- same effect across different adipose tissue deposits

Question 2

markers for mitochondrial content in adipose tissue

Answer 2

COXIV protein content

citrate synthase activity

Question 3

liver adaptation to exercise

- markers

Answer 3

increased mitochondrial content

markers of this
- cytochrome C content

Question 4

skeletal muscle adaptation

• obese indv
• 8 weeks
• moderate intensity endurance training
• biopsies

Answer 4

increased

• CPT1 activity
• mitochondrial FA oxidation

Question 5

CPT-1 role

Answer 5

rate limiting step in FA oxidation

Question 6

effect of activation AMPK

Answer 6

induces GLUT4 and mitochondrial biogenesis

• protein phosphorylation

Question 7

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

Answer 7

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

Question 8

function of citrate synthase

Answer 8

initial enzyme in TCA cycle

- catalyzes acetyl CoA + oxaloacetate = citric acid

Question 9

HIIT training benefits/negatives

Answer 9

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

Question 10

time to fatigue associated with

- 2 ways to prevent this

Answer 10

initial muscle glycogen

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

Question 11

glycogen supercomposition

Answer 11

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

** must deplete first for supercomposition to occur

Question 12

traditional carb loading technique

Astrand

Answer 12

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

Question 13

problems with traditional (Astrand) carbohydrate loading

Answer 13

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

Question 14

Sherman method of carb loading in comparison to tradition astrand method

Answer 14

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

Question 15

why see weight gain with carb loading

Answer 15

glycogen stores 2.6 grams of water per 1 gram

Question 16

benefits of high fat, low carb diets

Answer 16

increase capacity for fat oxidation

• increase citrate synthase (CS)
• increase B-hydroxyacyl dehydrogenase
• indicators of mitochondrial content

increase exercise performace
** previously untrained individuals

Question 17

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

Answer 17

untrained

• additional stress of low carb
• more endurance gains faster

trained
- high carb able to train harder

Question 18

carb intake during exercise

- aerobic exercise effects

Answer 18

increase time to exhaustion 30%

- above normal and maintained plasma glucose levels

Question 19

glycogen resynthesis after exercise

Answer 19

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***

Question 20

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

Answer 20

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

Question 21

effects of caffiene on performance

Answer 21

“postulated” increase in fat oxidation and improve endurance performance

*unclear

Question 22

travel path of caffeine

Answer 22

• quickly enters blood

- crosses all body membranes (including blood brain barrier)

Question 23

half life of caffeine

Answer 23

4-5hr

Question 24

how much caffeine is used

Answer 24

5-9mg/kg body mass

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

Question 25

amount of caffeine in drinks

Answer 25

coffee 16oz grande - 330mg ``` redbull 250mL (8oz) - 80mg ```

Question 26

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

Answer 26

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

Question 27

effects of caffiene on exercise

Answer 27

large increase in time to exhaustion ex. 85% VO2max

Question 28

recent evidence of the mechanism of caffeine enhances performance

Answer 28

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

Question 29

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

Answer 29

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

Question 30

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

Answer 30

central and peripheral benefits | - ion Ca 2+ handling?

Question 31

caffeine on sprint exercise | - central vs peripheral

Answer 31

no benefit - purely anaerobic - single and multiple sprints

Question 32

side effects of caffeine

Answer 32

``` anxiety jitters insomnia inability to focus GI upset irritability etc ```

Question 33

amount of caffeine on side effects

Answer 33

mild effects - >6mg/kg body mass minimal effects - 3-6mg/kg body mass *highly variable between individuals

Question 34

active component of beet root juice

Answer 34

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

Question 35

physiological benefit of beet root juice

Answer 35

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

Question 36

beet root juice experiment | - benefits on exercise

Answer 36

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