Does increasing the speed of ankle plantarflexion with a straight knee increase gastrocnemius activation and decrease soleus activation?

When we look at the data, we see that 26 studies support, 0 studies refute ¹. The evidence we have reviewed leans toward the idea that speed matters when you are pointing your toes. The gastrocnemius is the larger muscle you can feel on the back of your lower leg. The soleus sits just beneath it. Our analysis indicates that quick movements with a straight knee naturally shift the workload toward the outer muscle and away from the deeper one.

We want to be clear that this is a partial view that improves over time. The evidence we have reviewed leans toward this specific muscle response, but we continue to track new research as it becomes available. Not every movement or training style will produce the exact same result, and individual anatomy can play a role.

For everyday training, this means you can adjust your pace to change which part of your calf feels the work. If you want to focus more on the outer calf, try pointing your toes quickly while keeping your legs straight. If you prefer a steadier effort in the deeper muscle, slow down the movement. We will keep monitoring the research to see how these findings hold up as more data comes in.