Lateral Head of the Gastrocnemius

The lateral head is the outer head of the two gastrocnemius heads that are located at the rear of the lower leg. Gastrocnemius is Greek means ‘The belly of the calf’.

The gastrocnemius creates the distinctive shape of the calf and is an important muscle for overall leg development and symmetry.

The gastrocnemius is recruited during extension of the ankle, where the body is upright and there is no significant bend in the knees. It is important to work the gastrocnemius through its full range of motion (ROM), as it has been shown that the gastrocnemius is more active during the eccentric phrase of the extension of the ankle. For this reason, performing an exercise such as the calf raise is best done in a slow controlled way, reaching full contraction at the top, and a controlled eccentric phrase, with also a stretch at the bottom of the movement.

The gastrocnemius has a higher ratio of type ii fibres compared to that of the soleus, which has an abundance of type i fibres. Therefore, the gastrocnemius is best recruited when the load is increased so that the larger motor units in the gastrocnemius start firing to execute the lift, leaving the soleus more inactive.

Many trainers have the view point that emphasis can be shifted from one head to the other by shifting feet position during flexion of the ankle. 'Toes in' - working the lateral (outer) head, and 'toes out' - working the medial head.
Studies have shown that using a position where the toes are pointed in during the execution will lead to stimulation of both heads equally. So the view point that toes pointing inwards shifts emphasis on to the lateral head is untrue. It however has been discovered that pointing the toes outward during execution does seem to activate the medial head to a greater degree. So this viewpoint holds substance (Dr. Per Tesch MRI research).

8-15 reps will likely provide optimal time under tension for the gastrocnemius muscle, providing adequate stimulation for sarcoplasmic hypertrophy, and acute response to anabolic hormone concentrations, compared to that of lower rep ranges.