Training Calves: High or Low Reps?

by Sean Sullivan

Muscles are made up of thousands of tiny fibers. These fibers are broadly classed as either slow twitch, or fast twitch muscle fibers.

Slow twitch muscle fibers respond better to higher repetition work. They contract slowly, but can work for a long time without getting tired.

Fast twitch muscle fibers respond better to low repetition work. They contract and tire quickly.

Genetics determines the mixture of each type of fiber an individual possesses in any given muscle. On average, most muscles used for movement are made up of about 50% slow and 50% fast fibers. Individual variation is cause for why some weight trainers respond better to higher or lower reps for various muscle groups. A predominant amount of one type of fiber in a muscle can make an individual better suited for shorter, or longer duration activity (low reps or high reps in weight training). For example, Olympic sprinters have been shown to possess about 80% fast twitch fibers, a mixture that naturally leads them to excel in that type of short, fast burst activity.

Calves differ from other muscles in the body though. There are basically two muscles that make up the rear of the calves, the soleus, and the gastrocnemius.

The soleus contains mainly slow twitch muscle fibers. Therefore, it responds better to higher reps. In contrast, the gastrocnemius contains mostly fast twitch fibers and responds best to lower reps. Both high AND low repetition sets should be incorporated into a calf routine for the soleus and gastrocnemius to each get the stimulation they respond best to. Other muscles in the body could benefit most from one type of rep scheme or the other depending upon the individual’s mixture of fiber types, which is based on their genetics.