My first experience with my calves cramping was way back in my teens. I'd jump on my 10-speed and pedal as fast as I could around Six Mile and Lake Saint Clair up in Ellsworth, Michigan. About a quarter of the way around, a calf would cramp. I'd get off the bike, stretch for a minute, and I was good to go. A couple rides later, I discovered that if I stretched a bit BEFORE I started riding, I didn't have the problem.
Decades later, with nary a cramp during all those years, suddenly I started cramping again. The first time was at the end of hill intervals. I'd spent about 25 minutes of work effort over about 10 intervals. Well satisfied with my effort, I started my easy warm-down ride back to the car. CRAMP! What the????? I jumped up and stretched my calf while still on the bike, alleviating most of the pain, then gingerly biked the rest of the way back. Within 10 minutes, the cramping was completely over.
The next couple rides were long slow distance rides, including one of 70 miles. No cramping.
Then it was the weekly Wednesday night King of the Hills ride with other Team NordicSkiRacer colleagues. Some king! I was definitely the pawn of the ride, roundly thumped by everyone. We made a hard run out and back over the hills at Kensington Metropark and I was off the back. Magnanimous as always, the torturers slowed down to let me catch up and catch my breath. We rode easily for a few minutes then CRAMP! And this was a big one! I don't ever remember agony like this. This one took a long time to go away and caused me to abandon the ride. Just 45 minutes of riding; I could feel tight calves for several hours. Luckily, nothing cramped overnight.
Googling the bike forums and talking to friends, I found lots of advice:
"Drink more water."
"Use an electrolyte supplement."
"Drink pickle juice."
"Do more interval days."
"Lower your bike seat."
There were no reasons behind any of the advice - it was all advice handed down from one friend to another. In a word, folklore.
A little more research provide list of potential causes of cramping:
Well, I certainly wasn't dehydrated, nor did I think electrolyte depletion was the issue. In both cases of cramping, the exercise sessions had been pretty short. (But I did start eating more bananas for potassium, just in case....). It wasn't a new activity. Poor conditioning? Maybe. Muscle fatigue? Maybe.
Wanting more, I searched for scientific articles. What I found surprised me:
Scientific evidence does not show a link between dehydration, electrolyte depletion and muscle cramping. Most of the research has severe methodological problems and the better research does not show a link. In fact, one study showed the reverse: athletes who cramped were slightly less dehydrated than the athletes who did cramp.
Thank goodness - I wasn't looking forward to carrying a water bottle of pickle juice on my bike.
The other three potential causes (doing a new activity, poor conditioning, altered neuromuscular control) all seem related to muscle fatigue. Fatigue can be caused by a number of factors including:
The research is fairly compelling: cramping seems to be neuromuscular in nature, and can be replicated in a laboratory setting. The growing evidence suggests cramping is from repetitive muscle contraction that results in muscle fatigue. (There's a complex cascading effect documented in the literature to explain the actually causes, but it's above my level of understanding. See "Causes of Exercise Associated Muscle Cramps (EAMC) -- altered neuromuscular control, dehydration or electrolyte depletion" (M.P. Schwellnus, 2008) for a review and citations to other research.
So we're my muscles fatigued to the point of cramping?
I bike 70 miles and have no problems. I ride hard for 30-40 minutes and cramp. What does the evidence show?
Linking the evidence: My foot was crunched because while riding hard, I was riding with my foot pointed down (and heel up). This put my calf muscle in a shortened position when applying pressure to the peddle. Because I'm not used to that position, it caused my calf muscle to fatigue more quickly, causing cramping. The suggestion to lower my saddle probably would have caused my heel to drop, putting me into a more fatigue-free position, thus reducing the chance of cramping.
Well, I did not lower my seat - that would really mess up my riding. But the next time I did hard uphill intervals, I focused on lowering my heel. The session was very hard - I was close to my max heart rate. I did several intervals, varying from a couple minutes to six. My legs were trashed when I was finished. I started my cool down ride back to the car and...
My story is anecdotal. I have yet to complete a second hard session to see if the results are replicated. I am feeling pretty confident, however, that my problem was not dehydration or electrolyte depletion, but muscle exhaustion caused by poor cycling technique.
Here's to less cramping and better training!