Josh

What about your wing chun club? There's an entire form for the use of butterfly knives!

This used to happen to me until I worked out what was going on .. my running technique was too tense, I would tense up my calves and sort of bounce on them like they were springs. Now that was an intense burn - its like sprinting long distance. So I just relaxed more, opened up my stride and the problem dissapeared. Now I can run my seven mile route at a good pace without pain in the muscles.