SAUNA Use

overview

• Thermoregulation, Acclimation to Heat
• Thermoregulation, Heat Acclimation
• Myths & Safe Sauna Bathing
• Safety Issues
• Randomized Controlled Trials
• Scientific Evidence
• Future Research, Potential Cognitive Benefits
• Potential Cognitive Benefits

Thermoregulation

• Core Temp (37 C/98.6 F)
• Core Temp (37 C/98.6 F)
• Homeostasis, Hyperthermia
• Homeostasis, Hyperthermia, Key Players
• Critical Core Temp (39.5 to 40.0 C)
• Eccrine-dependent Cooling-System
• Critical Core Temp Limitations (39.5 to 40.0 C)
• Eccrine-dependent Cooling-System
• Acclimation (approx. 7 consecutive days)
• Acclimation (approximately 7 consecutive days)

ACUTE Circulatory Adaptations

• Increased blood plasma volume (>10%)
• Increased blood plasma volume (>10%)
• Reduced *diastolic BP
• Reduced heart rate (
• Increased cardiac output (3-5%)
• Increased cardiac output (70%)
• Reduced peripheral resistance (40%)
• Increased forearm blood-flow (15%)
• Endothelial function improves w/ heating

Hormonal Changes

• Noradrenaline: (+) alertness
• Arginine vasopressin: (+) constriction
• ACTH: (+) corticosteroids
• Cortisol: (+) blood sugar, (--) immune

Post-Acclimation, Heat regulation

• Improved ability to dissipate heat
• Improved ability to dissipate heat
• Toleration of heat load improves
• Toleration of heat load improves
• One can perform more work in heat
• One can perform more work in heat
• Sweat rate is enhanced (up to 15%) 
• Sweat rate is enhanced (up to 15%) 
• Core temp takes longer to rise
• Core temp takes longer to rise

Myths About Sauna USE

• Children, older adults ...
• Cardiac patients should avoid altogether

Populations that Should Avoid Saunas

• Anhidrotic Ectodermal Dysplasia
• Anhidrotic Ectodermal Dysplasia
• Hyperhidrosis
• Hyperhidrosis
• Cystic Fibrosis
• Cystic Fibrosis
• Multiple Sclerosis
• Multiple Sclerosis
• Acquired core Temp Dysregulation (anesthesia)
• Core Temp Dysregulation (anesthesia)

Safe Use of Saunas

• Requires sufficient fuel & water
• Requires sufficient fuel, water, & sleep
• Avoid supplements (diuretics, stimulants)
• Avoid excessive sauna-bathing 
• Avoid exercise over-training
• Avoid excessive sauna-bathing, over-training
• Avoid alcohol
• Avoid alcohol
• Aim to increase well-being, not weight loss
• Avoid transdermal drugs, antihypertensives

ACSM HYDRATION Recommendations

• 16-20 oz, 4 hrs prior to
• 16-20 oz, 4 hrs prior to
• 8-12 oz, 10-15 mins before
• 8-12 oz, 10-15 mins before
• 3-8 oz every 15-20 mins during
• 3-8 oz every 15-20 mins during
• 20-24 oz for every .lb lost, within 2 hrs after
• 20-24 oz for every .lb lost, within 2 hrs after

Stop Signs

• Feeling dizzy or light-headed
• Feeling dizzy or light-headed
• Muscle cramps
• Muscle cramps
• Upset stomach, diarrhea
• Upset stomach, diarrhea
• Severe skin irritation or rash
• Severe skin irritation or rash
• Inflammatory pain that returns

Randomized Controlled Trials

• Gayda 2012 - hypertension, 2x DS+
• Sauna
• Kihara 2004 - CHF, 14x FIRT
• Infra-red
• Masuda 2005a - depression, 20x FIRT
• Masuda 2005b - chronic pain, 28x FIRT+

Untitled Slide

HEAT & Cognition

• Exercise: (+) executive function
• Exercise, heat: (+) endothelial function 
• Heat stress: (--) cog performance
• Exercise + sauna = added benefit ?

HEAT & AEROBIC EXERCISE (HEAT) TRIAL

• 3-arm Pilot RCT
• 2-arm Pilot RCT
• 16, bi-weekly, 50-min exercise
• 16, bi-weekly, 50-min exercise
• 10-15 min post-exercise sauna vs. control
• 10-15 min post-exercise sauna vs. control
• Pre-post assessments
• Pre-post assessments
• VR-enhanced exercise

Sean Mullen, PhD


seanmullen.com
exercisetechlab.com
spmullen@illinois.edu