There are several reasons for calf muscle pain. Most common reason is cramping either due to excessive sweating or infrequent water consumption. Drink at least 8 to 9 large glasses of water daily. Secondly, you could be having tight gastrosoleus muscle (calf muscle). Stretching exercises will help overcome pain from exertion. The most dangerous cause is blood clots,common in those who are over weight. However, the pain is excruciating and the calf will be swollen and warm to touch. It's more likely for venous blood congestion if you have a sedentary job.

Start with knee strengthening exercises. Sending you the link of the same below https://play.google.com/store/apps/details?id=com.technoherpes.kneepain Or you can search for " knee pain relieving exercises by kavin khatri " on google playstore