Why Sauna Bathing Is Recommended After Workouts: What Happens to Your Muscles Inside a Sauna

When we first installed a sauna in our walk-in closet during the pandemic, I wasn’t thinking about stress management or overall wellbeing.

Honestly, I bought it as a tool to support my workouts. At the time, I had just started a new weight lifting routine based on Ben Greenfield’s recommendations—and one of his recurring tips was adding sauna sessions post-exercise to enhance recovery and boost performance. That alone got my attention.

But once I started incorporating sauna bathing regularly, I noticed something deeper. It became more than just recovery—it became a ritual, a reset, and a daily moment of clarity.

If you haven’t yet read our guide on what happens to your body during a sauna session, you can check that out here. This post is all about what happens to your muscles after working out inside a sauna, and why it works.

What Happens to Your Muscles After a Workout?

To understand the role of sauna bathing, we first need to understand what’s happening in your body after exercise—especially resistance training.

After working out, your body is:

• Inflamed: Micro-tears in muscle fibers trigger an inflammatory response

• Oxygen-deprived: Muscles that worked hardest need increased circulation for recovery

• Loaded with metabolic waste: Lactic acid and other byproducts build up in muscle tissues

• Undergoing protein synthesis: Muscles are rebuilding stronger—but this takes time and resources

What a Post-Workout Sauna Session Does

Performance experts recommend sauna use after exercise because it supercharges your body’s natural recovery mechanisms.

Here’s how:

1. Increases Blood Flow to Muscles

Heat exposure causes vasodilation, expanding blood vessels and sending oxygen-rich blood to your tired, inflamed muscles. This speeds up nutrient delivery and waste removal.

According to a study in the Journal of Science and Medicine in Sport, sauna bathing significantly increases plasma volume and blood flow to skeletal muscles.

2. Promotes Muscle Growth (Hypertrophy)

There is research showing that heat stress activates heat shock proteins (HSPs)—special molecules that protect and repair damaged muscle cells. This supports faster recovery and potentially increases muscle size over time.

A study published in Cell Stress & Chaperones found that repeated heat exposure stimulates HSPs, which in turn support protein synthesis and cellular repair.

3. Reduces Muscle Soreness (DOMS)

Delayed Onset Muscle Soreness is common after intense strength training. Infrared and traditional sauna use both help reduce soreness by boosting circulation and supporting anti-inflammatory pathways.

Greenfield often pairs sauna with other recovery tools like cold therapy, but notes that heat is ideal immediately after training, especially for flushing waste and relaxing tight muscles.

4. Boosts Human Growth Hormone (HGH)

Regular sauna use (especially in longer sessions post-workout) has been shown to increase HGH by up to 140% according to studies. This hormone supports fat metabolism, muscle building, and recovery.

Bonus: Cognitive & Hormonal Recovery

Post-exercise isn’t just physical—it’s mental and hormonal too.

Sauna bathing triggers a parasympathetic shift in your nervous system (rest-and-digest mode), helping lower cortisol and calm mental stress after a demanding workout.

Final Thought

If you're training regularly—whether you’re lifting, cycling, or doing HIIT—adding a post-workout sauna session can be a game-changer.

It’s not just about muscle repair. It’s about supporting your long-term performance, mental clarity, and metabolic resilience.

For me, it started with Ben Greenfield’s advice. But it’s turned into a non-negotiable part of how I take care of my body.

Want the full breakdown of what happens to your body during a sauna session?
Check out our article: What Happens to Your Body in a Sauna