I've been suffering bad cramp in my legs on rides for ages (3 cramp free rides this year so far). I'd been trying deep muscle massage, but after 5 sessions with no significant change the masseuse said I should see my GP. He took some blood to check electrolytes etc, and I got a letter today saying I these was nothing unusual apart from "a slightly raised creatine kinase level" which is characteristic of muscle damage and I have to avoid "hard exertion" for 10 days before another test
Anyone know anything about this apart from ad hoc web searching ?

