Exercise Physiology: Theory and Application to Fitness and Performance 9th Edition by Scott Powers, Edward Howley

Exercise 8

What is the effect of training on the responses of epinephrine, norepinephrine, and glucagon to the same exercise task?

Step 1 of 2

Epinephrine and norepinephrine mainly function in mobilization of liver glucose and free fatty acids from adipose tissue, during an intensity exercise. However, endurance training causes a very rapid decrease in the plasma epinephrine and norepinephrine to a fixed bout. Compared to epinephrine, the concentration of norepinephrine is higher in trained individuals.

The decrease in the plasma concentration of these two hormones with endurance training is due to the reduction in glucose uptake by muscles. It also suggests that physical training increases the capacity of individuals to respond to extreme challenges.