Muscle cramps are an involuntary and painful contraction of muscles that can happen during prolonged effort. They often affect trail runners, especially uphill, downhill, or after several hours of effort. Several causes are identified:
- Electrolyte imbalance: excessive loss of sodium, potassium, and magnesium due to sweating.
- Dehydration: insufficient water and mineral intake during effort.
- Muscle fatigue: lack of preparation and endurance in the muscles used.
- Mechanical factors: an unsuitable stride, wrong shoes, or lack of muscle strengthening.
Hydration: the key weapon against cramps
Hydration is essential to avoid dehydration and compensate for electrolyte loss. Here’s how to manage your water intake properly:
Before the race
Drink 500 to 700 ml of water 1 to 2 hours before the start.
Add a pinch of salt or an electrolyte drink if you sweat a lot.
During effort
Drink regularly: 150 to 250 ml every 15-20 minutes, even if you’re not thirsty.
Alternate water and electrolytes to maintain a good mineral balance.
Watch out for excess! Too much water without sodium can cause hyponatremia (sodium deficiency).
After effort
Rehydrate with mineral-rich water (e.g., Saint-Yorre, Vichy Célestins).
Add a squeeze of lemon juice or baking soda to rebalance muscle acidity.
Nutrition: avoid cramps with the right diet
Nutrition plays a key role in preventing cramps. Here are the essential nutrients:
Essential electrolytes
- Sodium (salt): found in mineral waters and broths.
- Potassium: bananas, sweet potatoes, green veggies.
- Magnesium: almonds, dark chocolate, pumpkin seeds.
Nutrition strategy
- Before the race: meal rich in complex carbs (brown rice, sweet potato), with good hydration.
- During: natural energy bars, gels with sodium, dried bananas.
- After: recovery with a complete meal (protein + veggies + starches).
Training and muscle prevention
Good training drastically reduces cramp risk. Here’s how to adapt your prep:
Targeted muscle strengthening
- Plyometrics: jumps, lunges, squats to strengthen calves and quads.
- Proprioception: balance training on an unstable board to stabilize joints.
- Core work: strengthen your trunk to avoid early fatigue.
Intervals and endurance
- Work on lengthening your stride to reduce muscle tension.
- Progressive long runs to get your muscles used to prolonged effort.
- Alternate uphill/downhill to limit muscle fatigue.
Bonus tip: adopt active recovery (light stretching, massage) and test your strategies during training before an official race.
Want to go further? Find our tips to adapt your daily diet to your trail running by clicking here
