Standing calf raise

Machine or dumbbells

With the knee straight, the gastrocnemius is in its strongest position, so it does most of the work of rising onto the toes.

What each muscle does in the standing calf raise

Muscle	Role	Action
Gastrocnemius	Primary	Plantarflexes the ankle and flexes the knee
Soleus	Secondary	Plantarflexes the ankle

Primary muscles are the prime movers; secondary muscles assist or stabilise. The balance shifts with grip, stance, range of motion and technique.