This short how-to explainer with PDF download is an accompaniment to the recent article on Heat Training for Cyclists by Dr David de Klerk.
Heat Training For Cyclists
A simple S2S protocol for building haemoglobin mass
50min
DURATION
Zone 2
56-75% OF FTP
5x/week
FREQUENCY
Simple
EXECUTION
The Protocol
1
Indoor Setup
Set up your indoor trainer in a warm room. Wear full winter kit: thermal base layer, long sleeve jersey, thermal tights, and consider adding a rain jacket. Turn off all fans and close windows.
Pro Tip
A spare room or garage works well. The goal is to make it uncomfortably warm—think summer ride in full winter gear.
2
Set Your Intensity
Ride at Zone 2 (60-70% FTP). This should feel conversational if it weren't for the heat. The heat provides the training stimulus—not the intensity.
ZONE 2 TARGET RANGE
FTP × 0.60 to 0.70
Example: 250W FTP = Hold between 150W & 175W
3
Duration: 50 Minutes
Maintain steady Zone 2 power for 50 minutes. Start with a 10-15 minute warm-up, then 50 minutes of heat exposure, followed by cool-down as needed.
Important
Stop immediately if you feel dizzy, nauseated, or develop a severe headache. These are signs of heat exhaustion.
4
Frequency Schedule
Building Phase: 5 sessions per week for 5 weeks
Maintenance Phase: 3 sessions per week for 3 weeks
Maintenance Phase: 3 sessions per week for 3 weeks
Scheduling
These can replace easy endurance rides in your training plan. Don't add them on top of your existing volume without adjusting total load.
5
Hydration Strategy
Limit fluid intake during the session—controlled dehydration is part of the stimulus. Weigh yourself before and after. Aim for 2-3% body weight loss during the session.
Critical
Rehydrate fully after each session. Drink 150% of weight lost (e.g., 1kg lost = 1.5L fluid intake over next 2-3 hours).
6
Monitor Core Temperature (Optional)
If you have a Core sensor or similar device, aim for core temperature around 38.5°C (101.3°F). However, this isn't essential—controlled dehydration and elevated RPE are reliable indicators.
Alternative
Track RPE and sweat rate. You should be sweating profusely and feeling uncomfortably hot by minute 30.
7
Track Your Progress
Record: (1) Body weight before/after, (2) Average power and HR, (3) RPE for the session, (4) How you felt. Work with an S2S coach or qualified physiologist to analyse training response, track adaptation and fitness trends.
Success Indicators
After 2-3 weeks, the same session should feel easier. Your HR should be lower for the same power output.
Key Points to Remember
Heat ≠ Hard
Keep the intensity at Zone 2. The heat provides the training stimulus, not high power output. Going too hard defeats the purpose.
Dehydration Drives Adaptation
Controlled dehydration during sessions triggers plasma volume expansion. But always rehydrate fully afterwards—this is when the magic happens.
Altitude Alternative
Research shows 5 weeks of heat training increases haemoglobin mass by 2-4%, comparable to altitude camps. More accessible and easier to manage around life and training.
Manage Total Load
Heat training adds physiological stress. These sessions should replace easy rides, not be added on top. Monitor recovery carefully, especially in the first week.
Track Trends, Not Single Sessions
One hard session doesn't mean it's not working. Look for improvements over 2-3 weeks: lower HR, better heat tolerance, faster recovery.
Not for Everyone
If you have cardiovascular issues, blood pressure concerns, or heat sensitivity, consult a physician first. Always stop if you feel unwell.
