Joined: Aug 2008
Posts: 13,127
Likes: 2,154
From: Ann Arbor, MI
Bikes: 15 Kinesis Racelight 4S, 76 Motebecane Gran Jubilée, 17 Dedacciai Gladiatore2, 12 Breezer Venturi, 09 Dahon Mariner, 12 Mercier Nano, 95 DeKerf Team SL, 19 Tern Rally, 21 Breezer Doppler Cafe+, 19 T-Lab X3, 91 Serotta CII, 23 3T Strada
I know a few people who swear by Sportlegs pills as a prophylactic. I tried them once, before a workout, and didn't notice them to prevent cramping in that case, but in their defense, I did go a little under the prescribed amount (IIRC, it's one pill per 20lbs body weight).
Anyway, cramping is usually from working beyond your typical exertion range, so training will take care of them, but they are nasty enough when they strike that something like Sportlegs may be handy when you know you're going to be riding hard/long.