Review Question - QID 6537

Endurance training primarily involves aerobic activities and results in different muscular adaptations compared with resistance training. The most important adaptation is a significant increase in the capillary density of active muscles. The respiratory capacity of mitochondria is increased, resulting in greater maximal oxygen consumption; however, there are no significant changes in the activity of glycolytic enzymes. With resistance training, initial gains in strength observed are caused primarily by an increase in the number of motor units recruited to execute a particular movement. After approximately 4 to 6 weeks, individual myofibers begin to exhibit hypertrophy. Other changes that occur with muscular resistance training include an increase in the number of type IIA fibers with a concomitant decrease in type IIB fibers.