Palmar Cooling
Cooling the palms during exercise to extend training capacity and improve performance
Bottom Line
Palmar cooling is one of the most underrated performance interventions. Stanford research shows it can dramatically increase training volume - some studies show 144% more pull-ups over 6 weeks. The mechanism is simple: cooling glabrous (hairless) skin on the palms rapidly extracts core heat, delaying fatigue.
If you hit a wall during training due to overheating, this works. DIY options are nearly free. The effect is immediate and measurable.
Science
Key finding: Stanford research showed 144% more pull-up volume over 6 weeks with palm cooling between sets.
Mechanisms:
- Palms contain AVAs (arteriovenous anastomoses) for rapid heat exchange
- Cooling palms quickly reduces core temperature
- Lower core temp delays CNS fatigue response
- Muscle enzymes work better at optimal temperatures
Key studies:
- Grahn et al. (2012): 144% more pull-ups over 6 weeks
- Heller & Grahn (2002): Palm cooling matches whole-body cooling
- Grahn et al. (2005): Increased bench press volume
Effect sizes:
- Training volume: Large (when heat-limited)
- Strength gains: Moderate (via increased volume)
- Endurance: Moderate (in hot conditions)
Limitations:
- Only works when heat is limiting factor
- Less benefit in air-conditioned gyms
- DIY methods work nearly as well as $1,000 devices
Supporting Studies
8 peer-reviewed studies
View all studies & compare research →Practical Protocol
Critical: Use 50-60°F water, NOT ice. Too cold causes vasoconstriction and defeats the purpose.
Basic protocol:
- Cool palms between sets (not during)
- Use 50-60°F / 10-15°C water
- Hold 30-90 seconds per rest period
- Keep palm flat against surface
DIY methods:
- Frozen water bottle in thin towel
- Bowl of cool water + ice
- Metal dumbbell or barbell
- Wet towel from fridge
Common mistakes:
- Ice directly on palm (too cold)
- Cooling during sets
- Not cooling long enough
Risks & Side Effects
Known risks:
- Essentially none when done correctly
- Too-cold temps reduce effectiveness
Contraindications:
- Raynaud's disease
- Cold urticaria (cold-induced hives)
Interactions:
- None - compatible with all training
Who It's For
Ideal for:
- Anyone who overheats mid-workout
- High-volume training (bodybuilding, CrossFit)
- Hot gym environments
- Endurance athletes in heat
Skip if:
- Training in cold/AC environments
- Doing short, low-volume sessions
- Have Raynaud's disease
Best results with:
- Multiple sets per exercise
- Sessions 45+ minutes
- Compound movements
How to Track Results
What to measure:
- Total volume (sets × reps × weight)
- Reps on later sets vs baseline
- Subjective fatigue mid-workout
Tools:
- Training log or app
- Infrared thermometer for water temp
Timeline:
- Immediate: Same-session improvement
- 4-8 weeks: Strength gains from added volume
Signs it's working:
- More reps on later sets
- Less mid-workout fatigue
- Feel cooler despite high effort
Top Products
Best value: A $15 frozen water bottle works nearly as well as the premium devices. See heatdumping.com for product comparisons.
Premium devices ($900+):
- CoolMitt (~$995) - Stanford-affiliated, vacuum seal
- NICE ROCC (~$975) - USB-C rechargeable, 1.5hr battery
- Kühler (~$900) - No ice/water needed, week of battery
Mid-range ($50-300):
- Therabody RecoveryTherm Cube (~$199) - Hot/cold therapy
- Black Ice CulCan (~$50) - Portable aluminum, 60 min cooling
- The Narwhals - Passive cooling, no charging
DIY (equally effective):
- Water bottle (~$15) - freeze, wrap in towel
- Small cooler ($20) - keep water cold at gym
- Bowl + ice + water (free)
What to avoid:
- Ice packs directly on skin
- "Cooling gloves" without temp control
Cost Breakdown
Free:
- Bowl of cool water
- Metal gym equipment
Budget ($5-50):
- Frozen water bottles ($15)
- Small cooler ($20)
- Black Ice CulCan ($50)
Premium ($900-1,000):
- CoolMitt, NICE ROCC, Kühler
Start with a frozen water bottle. Premium devices are for pro athletes or those who want convenience.
Podcasts
Supercharge Exercise with Cooling
Cool your palms between sets to boost training volume by 50% or more. Stanford research showed...
Craig Heller on Temperature & Performance
Rising core temperature limits exercise performance more than muscle fatigue. Palm cooling...
Essentials: Increase Strength & Endurance with Cooling Protocols | Dr. Craig Heller
Cooling your palms between sets can double or triple your workout volume - but ice on the neck...
Essentials: Supercharge Exercise Performance & Recovery with Cooling
Andrew Huberman explains how temperature regulation is the most powerful variable for improving...
Discussed in Podcasts
Palmar cooling for performance: cool the palms between sets to extend exercise capacity
Glabrous skin on palms, soles, and face has special blood vessels for rapid heat exchange. Cooling palms between sets prevents core overheating, the real limiter of performance, extending work capacity dramatically.
Glabrous skin AVAs can accept warmer temperatures too -- discovered via anesthesia research
Craig Heller discovered that the special AVA blood vessels in palms and feet efficiently transfer both heat and cold.
Glabrous skin heat portals: palms, soles, and face have unique blood vessel shunts
Hairless "glabrous" skin on palms, soles, and face contains arteriovenous anastomoses (AVAs) that shunt blood directly from arteries to veins.
3 heat dump zones: face, palms, and foot soles have special blood vessels (AVAs)
Beyond core and periphery, three glabrous skin areas with arteriovenous anastomoses can rapidly dump heat from or bring cool into the entire body.
Palmer cooling prevents overheating, extends performance, and protects against hyperthermia
Heat raises heart rate via cardiac drift, leading to quitting.
Use caffeine before workouts, avoid NSAIDs: both affect body temperature regulation
Caffeine should be used before (not after) exercise.
Who to Follow
Researchers:
- Craig Heller, PhD - Stanford biologist, pioneer of palmar cooling research
- Dennis Grahn, PhD - Stanford researcher, co-developed cooling technology
- Andrew Huberman, PhD - Popularized the research widely
Synergies & Conflicts
Pairs well with:
- High-volume training
- Caffeine (offsets heat from stimulants)
- Hot environments
Timing:
- Between sets, not during
- Most valuable in second half of workout
Less useful when:
- Training in AC environments
- Low-volume strength work (1-3 sets)
What People Say
Reddit:
What people say:
Common complaints: