Successful calf development starts with an understanding of the anatomy and muscle fiber types involved, which directly influence the exercises, rep schemes, and loads used. The calves are made up of two primary muscles — the gastrocnemius + soleus.
- The gastrocnemius is effectively the biceps of the lower body. It’s the visible muscle that bulges out of any pair of killer calves, and conversely, is noticeably absent from toothpick legs. It’s composed of 2 different heads (medial and lateral) that together create a diamond shape when grown out.
- The soleus is a long, flat sheath of muscle tissue that runs down the back of the leg. It sits underneath the gastrocnemius and Achilles, and because of that, isn’t actually visible.
Aesthetically, it adds height to the gastrocnemius and helps it pop out of the legs with 3D-like effect. It also specializes in endurance-based activities (more on that in a second) and works synergistically to improve the strength of your lower legs, which directly translates to accelerated growth.
But there’s one key difference that has massive implications for calf training — muscle fiber types. The gastrocnemius is predominantly composed of fast-twitch fibers (FT), while the soleus is made up of slow-twitch fibers (ST). Translated for training purposes, FT fibers generate power and respond better to heavy loads; ST fibers are more conducive to endurance-based aerobic training and respond better to higher reps.
Combine the two effectively—leveraging their individual attributes—and you’ll see growth skyrocket. But don’t worry, we’ve done the heavy lifting for you.
- Straight-leg — all straight-leg exercises, usually done standing, primarily hit the gastrocnemius. They also hit the soleus, but to a smaller degree.
- Bent-leg — all bent-leg calf exercises, usually done sitting, almost exclusively work the soleus.
- Don’t use momentum or bounce — the recoil takes most of the emphasis off the calf muscles (it displaces it to your Achilles).
- Always aim to increase the weight over time — go HEAVY.