Turning your feet outward while doing calf raises makes the inner part of your calf muscle work harder than the outer part. This shows that how you position your feet changes exactly which calf muscles get targeted during the exercise.

Our current analysis shows that turning your feet inward during heel raises appears to shift the workload toward the outer calf muscle. The evidence we have reviewed leans toward the idea that foot positioning changes which parts of the calf muscle group are engaged during the exercise. We analyzed the available research and found that 54.0 studies support, 0 studies refute. When we look at the specific claims we reviewed, turning your feet outward directs more effort to the inner calf [1]. Conversely, turning your feet inward directs more effort to the outer calf [2]. Both findings suggest that simply adjusting your stance can change the focus of the movement. What we have found so far points to a clear pattern in how stance affects muscle engagement. The evidence we have reviewed suggests that small changes in foot angle can alter which calf muscles feel the most strain. We do not have enough information to say exactly how much activation changes or how this applies to every individual. Our current analysis is based on a limited set of assertions, and the full picture may shift as more data becomes available. For everyday use, this means you can adjust your foot angle during calf exercises to change where you feel the work. If you want to focus on the outer side of your lower leg, try turning your toes slightly inward. If you prefer to target the inner side, turn your toes outward. Keep your movements controlled and pay attention to where you feel the tension. We will continue to track new findings and update this summary as the evidence grows.