Lecture 8: Nanci Guest

Question 1

What is Nanci’s research on?

Answer 1

Do our genes modify the response to caffeine associated with athletic performance?

Question 2

Mechanism of caffeine

Answer 2

• block adenosine (a relaxing and calming NT)

- increase NT (dopamine, adrenaline, noradrenaline, serotonin)

Question 3

Effects of caffeine

Answer 3

• increase energy and arousal during exercise
• increase pain threshold
• decrease rate of perceived exertion (RPE)

Question 4

When does caffeine work best?

Answer 4

tired at the end of a race (last 30-60 min)

Question 5

What are responders and non-responders?

Answer 5

Responders: shows positive OR negative effect to caffeine

Non-responder: no effect in response to caffeine

Question 6

Negative symptoms to caffeine

Answer 6

• trouble sleeping at night

- overly stimulated

Question 7

What type of athlete is caffeine most effective for?

Answer 7

endurance (75% of endurance athletes experienced about 3% performance improvement with caffeine)

Question 8

What factors were examined in response to caffeine?

Answer 8

• Power
• Strength
• Anaerobic exercise
• Aerobic capacity

Question 9

Why are participants asked to maintain their regular diet and exercise regime?

Answer 9

Want to make sure that the differences observed are due to treatment, not other factors

Question 10

Purpose of VO2 Max test

Answer 10

Determine maximal aerobic capacity (ability to absorb, transport, and extract O2 by the muscle cells)

Question 11

Exercise tests and what they tested

Answer 11

• Vertical jump (power)
• Hand grip (body strength)
• Wingate (anaerobic capacity)
• Time trial, 10km cycle (aerobic capacity)

Question 12

effect of caffeine on lactate levels

Answer 12

caffeine increases lactate levels

Question 13

Function of vit C in the body

Answer 13

• anti-oxidant
• immunity
• aids iron and folate absorption
• collagen formation (muscle repair)
• keeps vessel walls firm

Question 14

Effect of too much / little vit C for athletes

Answer 14

• Too much -> decreased adaptations to training

- Too little -> oxidative damage, muscle repair, premature fatigue

Question 15

General recommendation for vit C

Answer 15

150-200 mg/day

Question 16

using vit c depends on ___ gene

Answer 16

GSTT 1

Mutation of this gene means there is higher risk for deficiency when not meeting RDA

Question 17

what does GSTT 1 gene do?

Answer 17

affects processing of glutathione

Question 18

Are antioxidants good or bad during exercise?

Answer 18

• Low levels of free radicals needed to stimulate mitochondria growth
• antioxidants blunted ROS-mediated processes
• blunted improved VO2 max

Question 19

Main function of PGC1-a

Answer 19

regulate mitochondrial biogenesis

• exercise upregulate PGC1-a
• maximize metabolic stress to increase mitochondrial and blood vessel stress -> increase lactate threshold

Question 20

PGC1-a pathways (3)

Answer 20

1) mitochondrial biosynthesis
2) angiogenesis / capillarization
3) increased fatty acid oxidation (spare glycogen)

Question 21

Nutritional interventions for adaptive training

Answer 21

• Fasting
• Caffeine
• Low antioxidants

Question 22

Mechanism of NO increasing performance

Answer 22

Vasodilation

• work harder without feeling like it
• lower O2 cost for exercise