When a runner cramps late in a race, the explanation is almost always the same: not enough salt. Electrolyte drinks and salt tablets are sold as the cure. The reality is less convenient. Cramping is more closely tied to neuromuscular fatigue than to low salt.
What neuromuscular fatigue means
Late in a hard effort, the communication between your nervous system and your muscles starts to break down. Muscles that are pushed beyond what they are conditioned to handle become more likely to misfire. That is when cramps tend to appear: in the final miles, at a pace or duration the muscles have not been prepared for.
Why salt alone will not fix it
Electrolytes are not a universal cure for cramps. If the underlying cause is a muscle working past its conditioning, more sodium will not change that.
That does not make sodium useless. In long or hot efforts, sodium and fluids support plasma volume and fluid absorption. It is part of a fueling plan, not a cramp cure.
How to prepare for cramping
Condition the muscles for the demand. Race-specific work trains the muscles to hold the pace and duration they will face on race day.
Practice race-specific fatigue. Long runs with controlled race-pace segments and workouts that finish under fatigue prepare the neuromuscular system for the late stages of a race.
Prepare for heat. Heat exposure in training helps the body cope with hot race conditions.
Pace sensibly. Starting too fast spends what you need late in the race and pushes muscles into fatigue earlier.
Use sodium where it belongs. In long or hot efforts, as part of a fluid and fuel plan, not as the only defense.
How Catherine applies this
Catherine prepares you for late-race fatigue through race-specific workouts, sensible pacing, and heat preparation, and builds sodium and fluid into your plan for long or hot efforts. Cramping is treated as a conditioning problem first.