Training for Long-Distance Running Causes a Significant Increase in

Multiple Choice

Training for long-distance running causes a significant increase in

A) the cross-sectional area of slow-twitch muscle fibers (cells) .
B) the number of myofibrils per muscle fiber (cell) ,increasing cell size.
C) the number of slow-twitch muscle fibers (cells) .
D) A and B apply.
E) All of the above apply.