Cramps on the bike aren’t an electrolyte problem (most of the time)

Cramps show up when you ask a tired muscle to do one more hard thing—often in a slightly different position, in worse heat, or at a higher relative intensity than you trained for. Sodium gets blamed because it’s easy. The timeline doesn’t always fit.

Key Takeaways

• Cramps usually track with fatigue + specificity (duration, surges, bike position), not just “low electrolytes.”
• Heat/humidity can be the real trigger—it raises perceived effort for the same watts.
• Noxious tastes (spicy/sour) can buy you time when a cramp is brewing. It’s probably a reflex, not “absorbing minerals.”
• Train the race demand, not just FTP: repeat surges late in long rides, or do hard intermittent work.
• Here’s the catch: cramp-proofing one muscle can just move the problem to another.
• I can’t verify which cramp theory is “the one.” The practical playbook still works without picking a side.

Mechanism: what’s likely happening (without pretending we’ve solved biology)

One reported idea is that cramps come from nervous-system mismanagement as fatigue builds: too much “contract” signal, not enough “relax” signal. Another reported idea points to the business end of the chain—fatigued muscle fibers and motor nerve terminals getting twitchy and failing to settle down.

Either way, two observations matter more than the theory:

• Stretching often stops a cramp in the moment. That suggests a neural component, not just chemistry.
• Spicy/sour shots can blunt cramps quickly. That’s hard to square with “I absorbed sodium into my bloodstream in 45 seconds.” It looks more like a reflex that dampens motor neuron drive.

So…no, I’m not tossing electrolytes in the trash. I’m saying they’re not the whole story, and they’re often the wrong story.

Application: how to actually reduce cramps (race-world practical)

1) Train the demand that triggers you.
If cramps only show up in races, your training probably doesn’t reproduce the late-race combination: long duration + repeated surges + mental tension + sometimes heat.

Two ways to approximate that:

• Hard intermittent blocks
  • Example: 15 sec on / 15 sec easy for 15 minutes, repeat 2–3 times.
  • “On” should feel like 8–9/10, not an all-out sprint you can’t repeat.
  • This is the kind of work that makes legs feel “locked up” early season—then oddly fine a few weeks later.
• Long ride + late “matchbook” section
  • Ride endurance for 90–150 minutes, then do repeated 30/30s or short climbs hard.
  • You’re trying to recreate the moment you usually cramp: tired legs, then intensity.

2) Make conditions less surprising.
If cramps cluster in hot, humid events (or travel from dry Colorado to a swampy race), treat heat like a skill. Short heat exposures are often easier to recover from than one “surprise sauna” race day.

3) Respect position specificity.
Switching bikes or changing position can recruit muscles differently. A mountain bike’s stance, saddle height, and pedal stance can make a “new” muscle group take the hit. Same rider. Different demand.

4) Keep pedaling when it starts.
Not hero watts—just motion. Stopping completely can let the cramp fully clamp down. If you can hold a reduced steady output while it threatens, you sometimes prevent the full lock-up.

The cramp “oh no” button: spicy/sour as a tool, not a lifestyle

People experiment with spicy shots (hot sauce packets, purpose-built products) or aggressive sour candy. The common theme isn’t sodium—it’s noxious.

A workable pattern:

• Use it at the “pre-cramp” feeling, not after you’re already seized.
• Small doses can be enough. You’re trying to trigger a reflex, not marinate your esophagus.

If you’re going the candy route: here’s the catch—it’s a choking hazard when you’re breathing like a shop vac. If you try it, treat it like a quick rinse/trigger, then spit it out. (Also: I can’t verify that sour candy works the same way spicy liquids do. It’s plausible. Not proven.)

Tradeoffs and catches you should expect

• Cramp-induction rides can wreck you. They’re not free fitness. If you do them, place them where fatigue won’t blow up your week.
• Fixing one muscle can expose another. Strengthening adductors might just make your quads the next weak link. That’s not failure—it’s the system rerouting stress.
• Electrolyte experiments get confounded fast. You add more sodium when it’s hot, then conclude sodium caused the cramp. Maybe. Or maybe the heat did the obvious thing.

Takeaway: a boring plan that’s actually useful

If you cramp late in races, assume it’s fatigue + specificity until proven otherwise.

Train intermittent efforts when you’re already tired. Get some heat exposure if heat is part of the pattern. Be skeptical of “more sodium fixes everything,” but don’t ignore fueling/hydration basics either.

And carry one small, slightly disgusting tool you can deploy when the warning tremor hits. If it tastes like regret, you’re probably in the right category.