In the peak shift phenomenon, the peak performance shifts________________. to the training S+ b. to the training S- c. from the training S+ away from...

In the peak shift phenomenon, the peak performance shifts________________.

a. to the training S+

b. to the training S-

c. from the training S+ away from the training S-

d. from the training S+ towards the training S-

Can you also explain the peak shift phenomenon ?

Thank you