If you're a young woman doing calf raises, bending your knees while lifting will make your soleus calf muscle swell up more right after the workout than keeping your legs straight. This happens because the bent-knee position targets that specific muscle more intensely during the exercise.

When young women do calf raise exercises until they can't do any more, doing them with bent legs makes the calf muscle grow about twice as much as doing them with straight legs.

Doing calf raises with your legs straight builds more muscle in the back of your lower leg right after your workout than doing them with bent knees. In a study of young women, straight-leg raises increased muscle size by nearly 9%, while bent-leg raises actually caused a tiny decrease.

Doing calf raises with your legs straight causes your calf muscles to swell up much more right after the workout than doing them with bent knees. In a study of young women, straight-leg raises increased calf thickness by 14.5% right away, while bent-leg raises only increased it by 7.0%.

When young women want to strengthen their soleus muscle (the lower calf muscle), doing calf raises with bent knees works better than doing them with straight legs.

When young women do calf raises until they can't do any more, doing them with straight legs makes the outer calf muscle grow about twice as much as doing them with bent knees.