Hi, during my track practices I get random discomforts in my calves while running(or sprinting to be exact.) I'm usually accelerating about 30-40m before I feel something in my calf. My calf cramps up for no more than 1/2-1 second( or at least it becomes involuntarily tight- like a cramp) and then I stop running. I have had calf cramps, and I know how painful it is. But what I'm feeling is similar, but I'm not on the ground stunned and in pain for god-knows how long. Is it a pull, a strain or a cramp, or something else? Thanks. Another pain I feel is in my upper left leg. I'm not sure if it is in the quads or hamstrings because it is an internal pain. It isn't external and I can describe it as a sharp, but very mild pain I feel after slowing down right after a sprint drill For both cases, I usually just stretch it out for a few seconds, walk around a few minutes and resume training. Today I felt the same discomfort about 3 times( 2 times in my right calf.) I did the same procedure and ran again. What are they and how can I avoid them?