Lecture 8: Nanci Guest Flashcards
What is Nanci’s research on?
Do our genes modify the response to caffeine associated with athletic performance?
Mechanism of caffeine
- block adenosine (a relaxing and calming NT)
- increase NT (dopamine, adrenaline, noradrenaline, serotonin)
Effects of caffeine
- increase energy and arousal during exercise
- increase pain threshold
- decrease rate of perceived exertion (RPE)
When does caffeine work best?
tired at the end of a race (last 30-60 min)
What are responders and non-responders?
Responders: shows positive OR negative effect to caffeine
Non-responder: no effect in response to caffeine
Negative symptoms to caffeine
- trouble sleeping at night
- overly stimulated
What type of athlete is caffeine most effective for?
endurance (75% of endurance athletes experienced about 3% performance improvement with caffeine)
What factors were examined in response to caffeine?
- Power
- Strength
- Anaerobic exercise
- Aerobic capacity
Why are participants asked to maintain their regular diet and exercise regime?
Want to make sure that the differences observed are due to treatment, not other factors
Purpose of VO2 Max test
Determine maximal aerobic capacity (ability to absorb, transport, and extract O2 by the muscle cells)
Exercise tests and what they tested
- Vertical jump (power)
- Hand grip (body strength)
- Wingate (anaerobic capacity)
- Time trial, 10km cycle (aerobic capacity)
effect of caffeine on lactate levels
caffeine increases lactate levels
Function of vit C in the body
- anti-oxidant
- immunity
- aids iron and folate absorption
- collagen formation (muscle repair)
- keeps vessel walls firm
Effect of too much / little vit C for athletes
- Too much -> decreased adaptations to training
- Too little -> oxidative damage, muscle repair, premature fatigue
General recommendation for vit C
150-200 mg/day
using vit c depends on ___ gene
GSTT 1
Mutation of this gene means there is higher risk for deficiency when not meeting RDA
what does GSTT 1 gene do?
affects processing of glutathione
Are antioxidants good or bad during exercise?
- Low levels of free radicals needed to stimulate mitochondria growth
- antioxidants blunted ROS-mediated processes
- blunted improved VO2 max
Main function of PGC1-a
regulate mitochondrial biogenesis
- exercise upregulate PGC1-a
- maximize metabolic stress to increase mitochondrial and blood vessel stress -> increase lactate threshold
PGC1-a pathways (3)
1) mitochondrial biosynthesis
2) angiogenesis / capillarization
3) increased fatty acid oxidation (spare glycogen)
Nutritional interventions for adaptive training
- Fasting
- Caffeine
- Low antioxidants
Mechanism of NO increasing performance
Vasodilation
- work harder without feeling like it
- lower O2 cost for exercise
