Metabolic Effects of Exercise Flashcards
What is the relationship between work and oxygen uptake (VO2)?
With increasing work, oxygen uptake will increase linearly until the body reaches its maximum capacity to uptake oxygen
How is maximum uptake calculated?
VO2=max output x max O2 difference in arteries and veins
VO2max=COmax - max a-vO2 difference
What is a physiologic name for maximum uptake?
aerobic power
What are three factors that can affect max VO2?
1) Level of training–sedentary persons can lose up to 30% of their VO2 capacity in as little as 3 weeks
2) Age–drops after 20 yoa
3) Post-pubertal sex–males produce more Hgb
How long can the body maintain activity with:
1) ATP stores
2) Creatine-phosphate
3) Anaerobic activity
4) Aerobic CHO use
5) Aerobic fat use?
1) ~1 second
2) `3-15 seconds
3) up to 5 minutes
4) 2-3 hours
5) longer periods of time
How does a muscle determine which fuel to use?
1) Level of intensity—if the intensity is high, carbohydrates tend to be preferred fuels
2) Duration–if duration is high, fats tend to be used more
3) State of training
What are the three types of muscle fiber? What is their proportional representation in skeletal muscle as a whole?
Type I (slow oxidative twitch)--50% Type IIa (fast twitch, glycolytic/oxidative)--25% Type IIb (fast twitch, glycolytic)--25%
What are some general physical characteristics about Type I muscle fibers? What neurons activate them and what kinds of workloads are they used for?
They tend to be smaller in size, have many mitochondria, have low glycogen stores and high triglyceride stores. They are activated by Aalpha2 receptors and tend to be used for low workloads
What are some general physical characteristics about Type IIa muscle fibers? What neurons activate them and what kinds of workloads are they used for?
They tend to be intermediate in size and have intermediate quantities of organelles and food stores. They are activated by Aalpha1 receptors and are used for higher work loads
What are some general physical characteristics about Type IIb muscle fibers? What neurons activate them and what kinds of workloads are they used for?
They tend to be large in size with smaller numbers of most organelles. They have lower triglyceride contents, but much higher levels of glycogen. They are activated by Aalpha1 receptors and are used for high workloads
What is Henneman’s principle?
Type I fibers tend to be recruited first, followed by various Type II fibers. The exception to this rule is if there is a high-velocity activity
What is the effect of strength training on muscle?
Mostly hypertrophy of both type I and type II fibers due to increased sarcomeres
What is the effect of anaerobic training on muscle?
An increase in muscular enzymes and proteins and better lactate buffering
What is the effect of aerobic endurance training on muscle?
No noticeable difference in muscle fiber size. Increased oxidative capacity, glycogen content, fat metabolism, capillary density, mitochondrial number. Decreased glycogen stores and lactate.
