Many of my clients have complained about leg cramps while exercising. Here is some sound advice from Fraser Quelch, Head Coach & Director of Programs and Development at Fitness Anywhere Inc.
Muscle cramping is generally a cause of inadequate electrolytes / hydration or simply our body’s way of shutting things down in an act of self preservation. It can also be caused by an inadequate recovery time between workout sessions which will bring on an earlier onset of muscle cramping than normal. If you have just increased your volume of exercise or are new to the exercise you are performing, muscle cramps are not uncommon. Make sure that you are adhering to good nutritional principles and that you are well hydrated prior to working out and give yourself adequate recovery times between workout sessions. If you get a cramp, pause and try to stretch things out before resuming but if it returns you need to move on to exercises that target other areas of the body or stop your session all together. Your body is telling you it has had enough. Be sure to focus on your post workout recovery nutrition and get lots of rest prior to your next hard strength session. Performing some low level recovery cardiovascular exercise will also aid in speeding your regeneration.
I hope that this helps