Cold Plunge vs Sauna: The Ultimate Recovery Cheat Sheet for Size, Strength, and Growth

You see it all over social media. Your favorite influencer’s plunging into ice baths like it’s a rite of passage. The next reel? A sauna selfie. Gotta film it or it didn't happen, right?

These days it seems like everyone’s doing something “biohacker-ish”: Cold plunges, saunas, cryotherapy, red light therapy, ice baths, and more. But the truth is many of them are chasing likes, not results. Concerned with the latest algorithm trends than what actually builds muscle.

And that's the problem.

Many are sharing valuable information but without the most important context: When it comes to heat and cold, timing is everything.

Use them at the wrong time, and you’re blunting your muscle growth and strength gains. Use them right, and you’ll recover faster, grow bigger, and come back stronger than ever.

Let’s break it down with a simple cheat sheet you can use to get the most out of these powerful recovery tools.

Heat or Cold? The Recovery Tools Many Are Using Wrong

Cold exposure and heat exposure aren’t fads. They’re legit performance tools used by elite athletes for decades. Both cold and heat exposure can improve your quality of life, but they work best when used strategically.

Let’s start with the cold.

Cold Plunge: Powerful For Growth, But Only When Used At The Right Time

Cold plunges reduce inflammation, speed up recovery, and make you feel like a savage. But they also blunt the muscle-building signal if you use them too soon after training.

When NOT to Cold Plunge:

Immediately after resistance training. Why? Because cold exposure dampens mTOR signaling, the same process your body uses to trigger hypertrophy.

And we've known this for years. A 2015 study showed that cold water immersion attenuated (reduced) long-term gains in muscle mass and strength. It also blunted the activation of key proteins and satellite cells in skeletal muscle up to 2 days after strength exercise⁽¹⁾.

When to Use Cold:

• On rest days to reduce systemic stress.
• Later in the evening to help with sleep and nervous system recovery.

PRO TIP: If you’re going to do a cold plunge on a lifting day, wait at least 4–6 hours after your session to avoid blocking the anabolic response.

Now let’s talk about heat.

Sauna: The Undervalued Muscle Builder?

Heat exposure may actually amplify hypertrophy, especially if timed right.

Why It Works:

• Sauna bathing increases production of heat shock proteins⁽²⁾, which play a key role in muscle repair, mitochondrial health, and growth.
• It elevates growth hormone and improves insulin sensitivity, both of which support recovery and muscle preservation.
• It helps flush metabolic waste, improving circulation and nutrient delivery.

Best Time to Use Sauna:

• Post-lift (20–30 minutes after training) to boost blood flow and speed up recovery.
• On off-days for improved cardiovascular health^(3,4,5), stress management⁽⁵⁾, and potential cognitive benefits and muscle preservation.
• Before bed to help lower cortisol and improve sleep quality⁽⁶⁾.

The Hybrid Protocol (Elite Recovery Stack)

Want the best of both worlds? Try this (if you have access):

1. Post-workout: Skip the ice, hit the sauna. A 2021 study evaluated the effects of 12 high-temperature (100 °C/212 °F) sauna baths on body composition of 23 healthy young men and found that the sauna group increased muscle mass, bone mineral content, and bone density⁽⁷⁾.
   
2. 4–6 hours later: Cold plunge or cold shower. Now you can hit the cold plunge to reduce inflammation and calm the nervous system without affecting muscle growth.⁽⁸⁾

These Recovery Tools Are Powerful, But Timing Matters When It Comes To Muscle Growth and Strength Gains

Saunas and cold plunges aren’t magic. They’re not shortcuts. They’re not status symbols. They’re tools, and they work best when you know exactly when to use them.

Get the timing wrong, and you’re stealing gains from your future self, blunting hypertrophy, slowing strength adaptations, and undoing the hard work you just did. But get the timing right and you recover better, lift more, and grow faster.

That’s the edge.

That’s what separates people who train for Instagram from those who train for performance.

But here's the deal.

After you've hit the gym, the sauna, and the cold plunge, the most important factor in your recovery toolbox is sleep. Deep, uninterrupted, muscle-building sleep.

Sleep isn’t a luxury. It’s your #1 growth tool. Without it, you’re not growing, you’re not recovering, you’re just spinning your wheels. So if you’re serious about progress, you need to focus on getting good sleep.

RESTED-AF is formulated to help kick your body into recovery overdrive while you sleep. The kind of recovery that builds muscle, sharpens focus, and resets your system for another round of war. With two delicious flavors to choose from, we're sure you'll find one you love!

Train Hard. Recover Better. Wake up Refreshed.

References:

(1) https://pmc.ncbi.nlm.nih.gov/articles/PMC4594298

(2) https://www.mdpi.com/2813-0413/2/2/14

(3) https://www.sciencedirect.com/science/article/pii/S0531556521002916

(4) https://pmc.ncbi.nlm.nih.gov/articles/PMC8122786/

(5) https://pubmed.ncbi.nlm.nih.gov/32814462/

(6) https://www.mdpi.com/1660-4601/18/3/1105

(7) https://www.tandfonline.com/doi/epdf/10.1080/22423982.2024.2419698?needAccess=true

(8) https://examine.com/research-feed/study/0mjwe9/?srsltid=AfmBOoqv2gh6sj2-9BtHY5sYA4WDh5oD35x-tJfGJ_HG8iBgXI5zztrf