Editor’s note: This protocol shows how to use a variety of heat sessions to incorporate heat training into triathlon training. It’s author, Tim Crowley, is a triathlon coach based out of Clermont Florida and owner of TC2 Coaching LLC. He is also the Head Strength and Conditioning coach at Montverde Academy, as well as an author and speaker at clinics and conferences.
Developed and written by Tim Crowley, TC2 Coaching
Intro
The goal of heat training is to create heat adaptation without sacrificing quality within the training process. This protocol outlines the heat training practices I have been using with myself and the athletes who I coach. Living in central Florida where the temperature is 90° F/32° C and humid for 6 months makes training a challenge and heat training essential. I also coach athletes from both warm and cooler climates. This requires adjusting the process to meet the training and racing demands of the athlete.
Heat Loading Days: 2 per week
These days are somewhat intense heat sessions, and they are usually done indoors to control clothing, intensity, and airflow.
Bike
Use the indoor trainer with clothing that may include thermal tights, base layer, windbreaker layer, thermal cycling jacket, and CORE suit.
- 10 – 15 minute warm-up
- Intervals at a 1:1 ratio with durations of 30 seconds to 3 minutes in length with an intensity level of 100–110% of FTP.
- Heat Strain Index should reach 3.0 by around the 30-minute mark.
- Intervals will continue until they are completed, usually 16–30 minutes of total work time or until the heart rate reaches about 10 beats above threshold.
- Intensity is then scaled down to about 50–60% of FTP for 15 to 20 minutes.
- The goal is to get 20-30 minutes at a Heat Strain Index of 3.0-5.0 or above.
Run
Typically wearing an extra layer of clothing to increase the heat load
- 15-minute warm-up which will include running drills
- Hill reps- 4×30 seconds or 3×1 minutes on a moderate steep grade with an easy jog back.
- Main set options
- Intervals or fartlek done outside on flat to rolling terrain with a total 15–20 min of high-intensity work. Adding an extra layer will increase heat load.
- Treadmill – overdressed where conditions can be controlled. Layers can be added or taken off to keep heat strain in planned range. Example- 10–20x 90 sec threshold pace/ 30 sec rest
- Steady-state run for 2–4 miles flat or slight incline.
- The goal is to get 20–25 minutes at or above 3.0 heat strain
Normal Training, Mild Heat Loading: 2–3 per week
These are normal planned workouts with no specific plan for heat loading. Depending on the athlete’s heat adaptation and the climate they are training in, extra layers can be added to obtain the desired Heat Strain Index. This is easy to during run workouts but not so easy with cycling sessions once moderately heat trained. Arm warmers and a thermal vest work well to bump up the heat strain without impacting workout quality.
At the end of the work out when heat strain is elevated, easy aerobic volume can be added to allow for increased heat exposure and adaptations. This can include walking or easy spinning on the bike at lower intensities until the heat strain lowers.
Passive Heat Sessions: 3–4 per week
Using a hot tub at 104° F/40° C or a sauna can be an effective passive heat training modality.
- Hot tub: 10–15 minutes in the evening creates a slight heat load but also allows for recovery and better sleep.
- Similarly, sauna can be used in the same way, typically used for 20–30 minutes in the evening.
Note that the CORE sensor does not give accurate data in the hot tub or sauna. Tracking heart rate can give a good indication of heat load (the higher the heart rate, the higher the heat load).
Heat Stacking: 2–3 per week
This is a method of using passive heat training immediately after a workout that ends with a Heat Strain Index above 2.0. The hot tub works especially well with hot water immersion above 104° F/40° C for 10–15 minutes. This is a large stress so be careful and get out if you feel lightheaded or nauseous. Tracking your heart rate can help avoid too much stress.
Another stacking method is using two passive heat modalities to create a longer exposure. This can be done by using the hot tub immediately before the sauna. The preheating in the hot tub makes for a more effective sauna session.
Heat Adaptation Score
With the Heat Adaptation Score on the CORE app it is easy to start to quantify and plan your heat training and adaptations. Although passive heat training methods are not able to be tracked in the app at this point in time, this may happen in the future.
The goal is to raise the heat adaptation score on the CORE app approximately 10% per week. If starting from zero, it will take 9 weeks to become fully heat adapted or a Heat Champion. This will allow for quality workouts to be done without lowering intensity due to heat stress. Once the athlete becomes a “Heat Champion”, which is maintaining a 90% Heat Adaptation Score or higher, the athlete can shift into maintenance mode by doing 2-3 heat sessions per week to maintain heat adaptation score of 90%, while allowing for higher levels of fitness.
At this point cooling strategies can be employed to figure out what works best for the athletes in non-heat training sessions. This can include indoor workouts using fans, cooling vests for pre-cooling to maintain a lower core temperature and heat strain.
In addition to heat training, passive heat training and cooling strategies, you can also see how well your body gets rid of heat by watching how quickly it returns to a Heat Strain Index of 1.0 post-workout when you return to normal house/air-conditioning temperatures.
I measure this after heat training workouts to see how quickly my body can return to normal heat strain. When highly heat trained, I can go from a 5.0 Heat Strain Index to 1.0 in less than 10 minutes. The body's ability to get rid of excess heat is a key adaptation to heat training.