Played a lot of football, still do play and don't have any leg issues. Now that I'm boxing training seriously, I keep getting issues with either cramp, or cramp feelings in my calf.

I've had full blown cramp twice in 8 weeks and seem to have regular issues with the calf's in both legs, aching early in the session and I just can't stretch it out.

I'm sure its a common problem given the strain put on those muscles when boxing.

Any ideas? Lack of water, not enough something in my diet, simply not fit enough?