Question

We can burn various sources in our diet for fuel....which sources of fuel do we use for long term low energy exercise vs. short term, high energy exercise? Why? When we examine VO 2 max we can see that the capacity for an individual to use oxygen is very closely related to the type of muscle tissue that person has accumulated. Activities that include aerobic exercise and the deposition of oxidative muscle tissue will allow an athlete to use oxygen (higher VO 2 max) than an athlete that has focused on the use of anaerobic tissue. Define the term VO 2 max and explain how it differs in athletes based on their activity. Take a look at the differences between glycolytic and oxidative muscle tissue. Notice that there are three main types of muscle tissue. Define these muscle types and what differentiates them. Give a good description of each type of muscle tissue and be thorough in your explanation for how they differ. Your description should include the terms Type I, Type IIA and Type IIX, oxidative, glycolytic, mitochondria, myoglobin, blood vessels, and a discussion of the fuel sources for each type. Please do your best here. It is okay to make a first attempt and discuss gaps in your knowledge or areas you may need to research further. You will have a chance to revise your answer for full credit.

Answer 1

Muscles utilize different fiber types for various types of exercise. Slow oxidative (Type I) fibers are used for long-term, aerobic exercises, and have high VO2 max due to their abundance of mitochondria and myoglobin. Fast glycolytic (Type IIX) fibers are used for short-term anaerobic exercises but fatigue quickly, and fast oxidative (Type IIA) fibers are intermediate in characteristics and fuel use.

Step-by-step explanation:

Muscles use different types of fibers for energy during short term, high energy exercise and long term low energy exercise. For short bursts of high-intensity exercise, muscles primarily use anaerobic glycolysis with fast glycolytic (FG) fibers (Type IIX). These anaerobic bursts are powered without oxygen, creating a powerful force, but causing quick fatigue.

VO2 max is the measurement of the maximum amount of oxygen an individual can utilize during intense exercise. Endurance athletes who engage in aerobic exercises have a higher proportion of Type I fibers, allowing them to have a higher VO2 max. Muscle tissue with more oxidative capacity will be better at using oxygen and therefore have a higher VO2 max.

Fuel sources for each type of muscle fiber differ. Type I fibers predominantly use fatty acids as fuel during prolonged low-intensity exercise, while Type IIX fibers rely on glucose during short, high-intensity exercise. Type IIA fibers can utilize both depending on the duration and intensity of the activity.