The Calf Raise works both your calf muscles: the gastrocnemius and soleus. These muscles work together when you are running supporting ankle flexion and extension, as well as providing power in the push off of your stride. This is also a great exercise to maintain calf strength if you have ever had achilles tendinitis.
Position your feet on a step such that your toe knuckles are aligned over the edge of the step. From here lower your heels down to feel a stretch through your calf. Then powerfully push your heels into the air so that you are on your tip toes. Repeat working through the full range of motion.
Ensure that your ankles stay in line with your feet and legs and do not fall out to the side. If you are struggling to balance you can hold onto something in front of you or to your side.
We would recommend you start with bodyweight while you perfect the technique, before adding a weight if you feel comfortable.