Sauna: What the Evidence Supports

The most robust evidence for sauna use relates to cardiovascular health outcomes, not acute training recovery. A 2024 review of passive heat therapy studies concluded that frequent sauna bathing is consistently associated with reduced cardiovascular disease risk and mortality, with evidence supporting a dose-dependent relationship. These benefits likely come from the way heat affects your body—helping blood vessels to relax and work better, keeping arteries more flexible, and increasing blood volume.

Together, these changes are some of the positive effects of doing regular cardio exercises.

For post-exercise recovery, the evidence is mixed. Sauna exposure increases heat shock proteins and improves circulation, which may help reduce muscle soreness, but measurable improvements in performance recovery are modest. The most reliable benefit is improved perceived recovery—feeling more relaxed and less stressed—which can still play a meaningful role in overall training consistency.

Sauna and Hypertrophy

One thing to keep in mind if your goal is building muscle: Using a sauna right after lifting might slightly reduce your body’s muscle-building response. The heat changes how your body directs blood flow and recovery signals, which can minimize that “growth window” after training.

Separate sauna sessions from a workout by a few hours (about 4 to 6) or use it on rest days instead. If the goal is more about heart health or general wellness, timing isn’t nearly as important.

Cold Plunge

Cold water immersion (CWI) has legitimate evidence for acute recovery from high-intensity or high-volume exercise in the context of back-to-back training days or competition. Research shows cold plunges can reliably reduce soreness in the 1 to 3 days after a tough workout and may increase performance sooner. The performance boost is usually small, but the soreness relief is real. This likely comes from the cold limiting inflammation, slowing blood flow, and temporarily dulling pain signals.

Cold Plunge and Strength Adaptation

This is where the evidence most clearly contradicts popular culture. Using cold plunges right after resistance training may slightly reduce long-term muscle growth compared to training alone. The effect isn’t huge, but it’s consistent enough to matter if your goal is maximizing size. This likely happens because the cold dampens inflammation and recovery signals that help drive muscle-building after a workout.

Practical Guidance

Cold plunging immediately after training can work against muscle growth and strength development. It’s best reserved for situations where recovery—not adaptation—is the priority:

• Back-to-back competition: Supports faster between-event recovery.

• Endurance athletes: Helps manage high training volume and frequent sessions.

• General wellness clients: Useful for relaxation without strength or hypertrophy goals.

Protocols Worth Knowing

• Cold plunge: 52 to 59 degrees Fahrenheit (11 to 15 degrees Celsius) for 10 to 15 minutes immediately post-exercise for recovery. Colder water adds discomfort without meaningfully improving results.

• Infrared sauna: Lower temperature, longer sessions. Typically, better tolerated, but with less robust cardiovascular evidence.

• Traditional sauna: 15 to 20 minutes at 176 to 212 degrees Fahrenheit (80 to 100 degrees Celsius), 3 to 4 sessions per week for cardiovascular benefits.

Sauna and Cold Plunge Recovery

Sauna and cold plunge are legitimate recovery tools, but they’re not shortcuts. The real foundation of recovery still comes down to sleep, nutrition, and well-designed programming. These modalities work best as add-ons, not replacements.

Apply sauna and cold plunges with intent:

• Prioritize timing if hypertrophy or strength is the goal.

• Use cold to manage soreness and high training demands.

• Use heat to support cardiovascular health and overall wellness.

Deepen your understanding of performance, recovery, and advanced programming with the National Academy of Sports Medicine (NASM) Performance Enhancement Specialization (PES).