How to build heat training into your training schedule as a runner
Running generates a lot of heat. If you heat up too much, you slow down. Runners know that intentional heat training helps them avoid overheating when it matters. They can maintain pace in hot weather, and even run intense treadmill intervals in an overheated gym. Runners also know that long-term heat training (5+ weeks) can give them hemoglobin gains similar to those found in altitude training.
CORE’s metrics make it easy to track your heat training.
- Heat Strain Index. Shows how hot you are in real time, and indicates when you’re in Heat Zone 3 (the ideal range for heat training).
- Heat Training Load. The cumulative amount of heat stress you’ve had each day.
- Heat Adaptation Score. Shows how well you’re heat adapted, from 0–100%
A sample runner’s schedule
CORE provides heat training schedules to boost your heat adaptation score in anywhere from 2–12 weeks. The gradual 12-week program is a favorite, as it’s easy to blend with your normal running schedule. You’ll need 2–3 heat sessions per week, each with a Heat Training Load averaging around 5.
Here’s what a 2-week block could look like. Blocks in red are when you do a heat session. This is easy to blend with a running schedule of less than 4 hours/week. Athletes running less than 40km (24 miles) per week may want to add more passive heat sessions.
| Monday | Tuesday | Wednesday | Thursday | Friday | Saturday | Sunday |
| Easy run. 50 minutes. Dress warm from the beginning. | Track intervals | Rest day | Tempo run. Start cool, then dress warm for 30 minutes while easy jogging. | Rest day | Easy run | Long run. Start cool, then dress warm for the last 75 minutes. |
| Easy run. 50 minutes. |
Track intervals. Run cool, then a 30-minute passive heat session. |
Rest day | Tempo run. |
Easy run. 50 minutes. Dress warm from the beginning
|
Rest day | Long run. |
Heat sessions in various workouts
Here are some details of how to build heat into each type of workout.
Easy run
To do a heat session during an easy run, overdress from the beginning. Because intensity is low, you’ll need to trap the heat you generate from the start of the workout. Expect to need 20–25 minutes to reach Heat Zone 3 (ideal heat training territory), depending on intensity and how warmly you’re dressed. During a 45–60 minute run, you can readily accumulate a Heat Training Load of 3–5.
Tempo/Intervals
During intense workouts, you’ll want to do the fast-paced work while your skin temp is cool, so dress lightly to not lose performance. You’ll generate a lot heat, and by the end of the intense portion, your core temp will likely have risen to over 38.3°C/101°F. Then, it’s a simple matter to add clothes to raise your skin temp and get into Heat Zone 3. Switch to an easy jog, and within 30 minutes you can pick up a Heat Training Load of 4–5. Or, on the treadmill, you can choose to increase the grade and do a steep, fast-paced walk while overdressed.
Long run
If your long run doesn’t have a pacing target, it can be a great way to incorporate heat. If you overdress from the start, you’ll need 20–25 minutes to reach Heat Zone 3. Spending an hour there will get you a Heat Training load over 7, and 1.5 hours will give you a Heat Training Load of 10. If your run is quite long, you can start cool and layer up part way through to get the desired heat dosage.
Sauna/hot bath
You can do some of your heat sessions ‘passively’ (in the sauna, hot bath, etc). Within 5–10 minutes of ending your run, hop into your favourite hot space. You’ll get a Heat Training Load of 5–7 within 30 minutes. But if you cool off first (or start from baseline temp), you’ll reach a much lower Heat Training Load. Be sure to take off your CORE sensor before entering the sauna/bath (it doesn’t work there). Use CORE’s Passive Heat Training Calculator to plan and record your passive sessions.