COACHING INSIGHTS · CRAMP · JUNE 2026

Cramp is one of the most frustrating things that can happen on race day. Understanding the real cause — and having a plan — makes all the difference.

TeamCPNZ Coaches Resource  ·  June 2026

WHY ATHLETES CRAMP

Cramp is almost a rite of passage in endurance sport — Coast to Coast, triathlons, long trail runs. It derails races, breaks momentum, and leaves athletes wondering what they did wrong. The good news is that cramp is largely predictable, largely preventable, and very manageable once you understand what’s actually driving it.

It’s Neuromuscular

The most important thing to understand about exercise-induced cramp is that it is primarily a neuromuscular event — not simply a hydration or electrolyte failure, despite what most sports drink marketing suggests.

Here’s what’s actually happening: when an athlete goes harder or longer than they’ve trained for, more muscle fibres are recruited for a sustained period. Eventually the neuromuscular junction — where the nerve signal meets the muscle — becomes fatigued. When that happens, it starts firing extra impulses, causing the muscle to spasm involuntarily. That’s cramp.

KEY PRINCIPLE

Elite athletes at major events rarely cramp — not because they have better electrolytes, but because they are trained to operate at that intensity. Cramp is the body’s signal that it’s been asked to do something it hasn’t been prepared for.

This is why cramp almost never happens in training but shows up on race day. The combination of a taper (feeling fresher than normal), race-day adrenaline, and crowd energy means athletes go out harder than their training has prepared them for — even though it doesn’t feel that way at the time.

Race Day Is the Perfect Storm

Several things converge at once on race day to create ideal cramping conditions:

• The taper effect: A well-executed taper leaves athletes feeling significantly fresher than their normal training state. Perceived effort at a given pace is lower than usual — which makes it easy to go out too fast without realising it.
• More muscle fibres activated for longer: Going harder means recruiting more fibres. Do that long enough and the neuromuscular junction fatigues. The further into a race, the lower the threshold for cramping.
• Specific race formats: Events like Coast to Coast start with a hard run off the beach, followed by a long bike with repeated efforts, followed by a run. Each discipline compounds the fatigue of the last. Cramp on the mountain run isn’t just about the run — it’s about everything that came before it.
• Adrenaline and elevated heart rate: Heart rate is elevated even on the start line which illustrates the extra adrenaline and the activated sympathetic nervous system.  The loud start line vibes and energy from other athletes means a higher effort can be sustained at least initially – but this comes at a cost later in the race.

Prevention: Train for the Intensity, Manage the Pacing

The most effective cramp prevention strategy is also the most obvious: train at the intensity you intend to race at. Beyond fitness preparation, pacing discipline in the early stages is the single biggest lever:

• Prepare for the intensity: Most of us do a good job of simulating the terrain and going long but make sure that you add the intensity that you plan to go. 
• Simulate Race Day – The best simulation session is a practice race in your lead up so you can practice your pacing strategy in a race environment. 
• Cramping prior to your key event: If you do cramp in a training session or a practice race this is great feedback to adjust your pacing or training.  It also means that the affected muscle groups will heal and get stronger so will be in better shape at your key race.
• Use a power meter on the bike: Power doesn’t lie and isn’t affected by adrenaline. Know the target number and sit with it regardless of how good the legs feel. Going over it, even briefly on climbs or chasing a wheel, burns matches needed later.
• Use heart rate in the first hour: In the opening stages of any long event, heart rate monitoring keeps intensity honest. Once 60–90 minutes in, adrenaline dissipates and natural rhythm takes over — at which point perceived effort becomes more reliable.
• Treat the first section as an investment: Athletes who cramp in the final third almost always went too hard in the first third. A conservative start is not lost time — it’s a deposit on a strong finish.

WORTH NOTING

On race day it is entirely normal to feel like you can go faster than your training paces. You probably can — temporarily. The question is whether you can sustain it. Trust the number, not the feeling.

What About Salt and Hydration?

The relationship between electrolytes, hydration, and cramp is more nuanced than most athletes assume. Dehydration and low sodium can contribute — particularly in heat or for heavy sweaters — but they are rarely the sole cause, and addressing them alone won’t reliably prevent cramp if intensity isn’t managed.

• Salt matters more for some athletes than others: Sweat composition varies significantly between individuals. Athletes who are heavier sweaters or lose more sodium in sweat are more susceptible to electrolyte-related cramping and benefit more from targeted sodium replacement.
• Many gels have very little sodium: Many modern gels contain minimal salt. Check the sodium content of race nutrition and supplement with salt tabs or an electrolyte drink if total intake looks low.
• Work out your sodium target in training: Establish an approximate target for milligrams of sodium per hour based on personal sweat rate and conditions, and practise hitting it in long training sessions before the event.
• Environment affects the equation: Hot, humid conditions increase sweat rate and sodium losses dramatically. What works in a cool New Zealand winter race may not be sufficient for a summer or overseas event.

Managing Cramp When It Happens

Even with the best preparation, cramp can still occur. How an athlete responds often determines whether it ends the race or just slows things down briefly.

IN-RACE CRAMP MANAGEMENT •      Keep moving — stopping and stretching is one of the worst responses. The muscle needs blood flow, not static tension. Walking or easy movement is far more effective. •      Cramp comes in waves — it peaks, then dissipates. An athlete who keeps moving will often find it eases within a few minutes. Don’t panic, don’t stop. •      Shift the load — if a specific muscle is cramping, reduce its demand temporarily by adjusting gait, cadence, or position. Bring other muscle groups into play. •      Avoid dismounting to stretch on the bike — getting off and then trying to remount usually triggers the cramp again. Manage it while staying in motion if possible. •      Nutrition can help — fast-acting carbohydrates provide a rapid energy top-up that reduces neuromuscular fatigue. If gels are still available late in the race, take them. •      Cramp Stop products (tart/vinegar-based) deliver a sharp sensory stimulus that resets the misfiring nerve signal. There’s a plausible mechanism and many athletes find them effective. Worth carrying in a race vest or jersey pocket.

Strength Training: The Underrated Prevention Tool

Strength training is one of the most effective and most overlooked cramp prevention strategies. Athletes who do regular, progressive resistance work are measurably less prone to cramping for several reasons:

• Higher fatigue threshold: Stronger muscles can sustain effort for longer before the neuromuscular junction begins to fatigue. The cramping threshold effectively rises with improved strength.
• Better economy and form under fatigue: A strong core and supporting muscles allow an athlete to hold proper form deeper into an event. Collapsing posture and compensatory movement patterns late in a race dramatically increase cramping risk — particularly in the hip flexors, adductors, and hamstrings.
• Specific movement strength: For trail and mountain events, exercises that train large step-up movements, lateral stability, and eccentric load of descending are particularly valuable. Technical terrain requires specific strength preparation, not just aerobic fitness.

For Our Athletes

Cramp is a topic that often comes up the week before a major event, when structural changes are no longer possible. At this point go in with a clear plan rather than cramp anxiety:

• Respect the taper — stick to your plan: Feeling great at the start line is the taper working. It is not an invitation to bank time in the first hour. Stick to the plan.
• Trust the device, not the legs: Power meter and heart rate are objective. Perceived effort on race day is compromised by adrenaline. Use the number especially in the first 90 minutes.
• Have a nutrition plan with sodium in it: Know the sodium target per hour and have a product to hit it — especially in warm conditions.
• Carry Cramp Stop: Does it work?  potentially but the placebo effect is a real thing so if it feels like it works, it probably will.  It gives athletes something to do when cramp hits rather than just suffering through it. 
• Keep moving if it happens: Cramp is not the end. It peaks and passes. Keep moving, shift the load, take on fast carbs, and give it a few minutes before assuming the race is over.
• Focus on the process: If cramp does occur use this as a reminder to check in on the things you can control, how’s your posture, are you following your hydration and nutrition plan, how is your technique.  Focus on the things that you can control and allow that to take your mind away from your cramping muscles
• Review your strength sessions: If cramping is a recurring issue, review your strength training with the specific areas that are cramping on race day.

 

QUICK REFERENCE — CRAMP MANAGEMENT ESSENTIALS

Primary cause	Neuromuscular fatigue — going harder than trained
Race day risk	Taper + adrenaline = easy to go out too hard
Best prevention	Pacing yourself – use a Power, Pace or Heart Rate — trust the number, not the feeling
Electrolytes	Contributing factor but not the main cause — manage sodium per hour
If it hits	Keep moving — don’t stop and stretch
Cramp Stop	Tart/vinegar formula — sensory reset of the nervous system
Nutrition	Execute your nutrition plan.
Long-term fix	Strength training — raises the fatigue threshold
Simulation	Do a practice race close to help simulate race day intensity and excitement