Using carbo-loading to increase the store of glycogen seems to benefit only those athletes who engage in aerobic activities that are ?

Using carbo-loading to increase the store of glycogen seems to benefit only those athletes who engage in aerobic activities that are -

Answer = more than 90 minutes.

Explanation:

well when looking at this if you think about it   negativley and positivley   react with each other and when the first layer gets full they add layers it starts with 2 on the first layer and it constantly goes on until the official number is there