I just completed my first marathon after 5 months of pretty intense
training. At mile sixteen, my calves started to cramp up. This had
happened to me on a 1/2 marathon I had done in April. During the 1/2
marathon, I stopped and tried to stretch out the cramps and couldn't.
In the marathon, thinking the same would happen, I kept going,
determined that I would adjust my stride or change my posture until the
cramps took me down. Well, I was successful in the fact that I finished
the marathon running, but I was 3 minutes over my goal. I felt I had
managed the first part of my run well and could have beat my time goal
if it weren't for the cramps. I was well hydrated and ready to run. In
both of these instances I was running downhill. Are my calves just not
strong enough? What gives?
Hi Dan. It sounds like you ran out of gas. Muscle cramping is usually a function of absent blood sugar. You actually have three sources of energy -
- the aerobic system which makes endless energy in the presence of oxygen, burning fat and sugar to make ATP's slowly.
- the lactate system which makes less ATP, but does so quickly. This system burns sugar to make ATP in the absence of oxygen, and can only make seven minutes of ATP.
- the creatine-phoshpate system makes small amount of ATP super, super fast. The ATP originates in stored ATP and in the creatine P inside the muscle. It does not need oxygen, fat or sugar to make ATP, but it's out put can only last 10 seconds!
My suspicion is that you were not adequately trained. Probably your carbo loading program broke down, or you ran faster than you were used to at times, burning stored sugar (glycogen) earlier than you anticipated....Do you drink sugar drinks like gatoraide? You might try carrying a glucose tablet in your pocket, and around mile 18, eat it! Better luck next time.