By Karyn Guidry, founder of Karyn Guidry Fitness
Hot weather workouts are not just uncomfortable, they push your physiology to its limit. As temperatures climb, your heart rate spikes, sweat pours faster, and your usual pace feels harder. The good news is that strategic heat acclimation can turn those challenges into performance gains. Below, I share my proven approach to heat adaptation so you can train smart, stay safe, and build resilience in the summer sun.
Why Heat Acclimation Matters
- More efficient sweating keeps you cooler.
- Lower core temperature during exercise.
- Improved blood flow to working muscles.
- Stabilized heart rate at a given workload.
- Reduced perceived effort in the heat.
Translation: the same workout will feel easier and more productive on a hot day once your body adapts.
Step-by-Step Heat Acclimation Plan
Week One: Controlled Exposure (twenty to thirty minute sessions)
- Train outdoors during cooler hours, early morning or evening.
- Keep intensity in Zone Two or conversational pace.
- Add a light jacket if conditions are mild to increase thermal stress.
Week Two: Increase Duration and Intensity
- Shift some sessions to warmer times of day.
- Extend workouts to forty-five to sixty minutes at moderate intensity.
- Add one or two short interval or tempo segments.
- Use perceived effort instead of pace; expect to slow slightly.
Week Three and Beyond: Match Race Conditions
- Train in peak heat once or twice each week.
- Rehearse fueling and hydration exactly as you will on race day.
- Balance hot sessions with cooler recovery workouts to avoid over-stress.
Hydration and Electrolytes
You cannot adapt if you are dehydrated. Follow these guidelines:
- Drink sixteen to twenty ounces of water one to two hours before training.
- Use electrolytes daily— LMNT, Liquid IV, or Nuun work well.
- For workouts longer than sixty minutes, sip four to eight ounces every fifteen to twenty minutes and take thirty to sixty grams of carbohydrates per hour.
Warning signs of dehydration: headache, dizziness, dark urine, muscle cramps, rapid heart rate. Stop and rehydrate if these symptoms appear.
What to Wear and Bring
- Lightweight moisture-wicking clothing (skip cotton).
- Hat or visor plus sunglasses and sunscreen.
- Cooling towel or ice bandana for long efforts.
- Hydration vest or handheld bottle for runs longer than forty-five minutes.
Mindset: Embrace Discomfort Without Burnout
Heat builds both physical and mental toughness. Use these reframes:
- “Today’s pace reflects the weather, not my fitness.”
- “Running slower now makes me faster later.”
- “Training outside gives me an edge while others stay indoors.”
When to Scale Back or Stop
- Nausea or chills.
- No longer sweating.
- Severe lightheadedness or confusion.
These signs signal heat exhaustion or heat stroke. Stop immediately, cool down, and hydrate, performance is never worth risking your health.
Boost Adaptation Without Extra Miles
- Post-workout sauna sessions enhance heat tolerance.
- Short hot yoga classes offer passive exposure.
- Recover with electrolytes, cold showers, and high-carb meals.
- Track heart rate and perceived effort to avoid overtraining.
Final Thoughts
Heat training is a powerful tool when applied intentionally. Build exposure gradually, fuel and hydrate wisely, and trust that every hot-weather workout is an investment in your endurance, speed, and grit.