Even the best runner is only as good as their weakest link. For many marathoners, including myself, that weakest link is their hamstrings. Over years of racing, I have many different obstacles, but the most frustrating problem for me has always been hamstring cramping during the latter stages of a marathon.
Many times I would feel amazing through 15–20 miles before being stopped dead in my tracks with uncontrolled spasming of my hamstrings. It usually starts as a light fluttering. It’s almost imperceptible but slowly it gets more intense and more frequent.
Athletes who have experienced it know the feeling, but the best way I can describe it is like the muscles are short-circuiting. If you have ever had electric stimulation done at the physical therapy office, it feels just like that. That is essentially what is happening: The muscles start firing at random in a short circuit.
photo: Justin Britton
Endurance, Not Electrolytes
Many athletes have been ingrained to think that cramping is caused by dehydration or electrolyte imbalance. That can certainly happen, but most athletes are prepared for that on race day. More likely the culprit is from fatigue that is overloading the nerves and causing a misfire to the muscle.
Just like the electrical stimulation you get at the PT office, your body sends electrical cues to your muscles. When you get out too fast in the early stages of the race or are unprepared for the pace you are running, it can leave you struggling to just keep one foot in front of the other.