Cold Plunge & Sauna: Do They Actually Help Recovery?

Everywhere you look, someone's sitting in an ice bath or sweating in a sauna.

Cold plunges are all over Instagram. Saunas are being installed in home gyms. Athletes, influencers, and biohackers swear by them for recovery.

But do they actually work? Or is this just the latest wellness trend that'll fade in a year?

After 13+ years of training clients and keeping up with the research, here's the truth: They work—but not for everyone, and not in the way most people think.

Cold Plunge (Ice Baths): What Actually Happens

Cold exposure—whether it's an ice bath, cold shower, or cold plunge—triggers a few physiological responses:

1. Reduces Inflammation

Cold constricts blood vessels, which reduces blood flow to the area and decreases inflammation. This is why athletes use ice baths after hard training sessions—it can help manage acute soreness.

2. Numbs Pain

Cold water literally numbs nerve endings, which reduces the perception of pain. You feel better temporarily because your nervous system is less sensitive.

3. Improves Circulation (After You Get Out)

When you get out of the cold, your blood vessels dilate rapidly. This rush of warm blood brings nutrients and oxygen to your muscles, which can aid recovery.

4. Boosts Mental Resilience

Sitting in freezing water is uncomfortable. Doing it regularly builds mental toughness and stress tolerance. The psychological benefits are real.

5. May Improve Mood and Energy

Cold exposure triggers the release of norepinephrine and endorphins, which can improve mood and give you a short-term energy boost.

The Problem With Cold Plunges for Muscle Growth

Here's where it gets tricky: cold plunges might actually hurt muscle growth if done at the wrong time.

Studies show that cold exposure immediately after resistance training can blunt the inflammatory response that's necessary for muscle adaptation.

When you lift weights, you create micro-damage in your muscles. Inflammation is part of the repair process. It's a signal that tells your body to rebuild stronger.

If you ice bath right after lifting, you suppress that inflammation—which can reduce muscle growth over time.

Bottom line: If your goal is to build muscle, don't do cold plunges immediately after lifting. Wait at least 4-6 hours, or save them for off days.

When Cold Plunges Actually Work

Cold plunges are most effective when:

• You're doing high-volume training: If you're training multiple times per day (like athletes), cold exposure can help manage cumulative fatigue.
• You need to reduce soreness quickly: If you have back-to-back hard sessions, cold can help you feel better faster—even if it slightly reduces adaptation.
• You're not focused on hypertrophy: If you're training for performance, endurance, or conditioning, cold therapy won't hurt you as much.
• You're doing it for mental health: Cold exposure has legit mood and stress-relief benefits. If that's your goal, go for it.

Sauna: What Actually Happens

Saunas work differently than cold. Instead of reducing inflammation, they increase blood flow and induce a heat stress response.

1. Improves Cardiovascular Health

Sitting in a sauna increases your heart rate and blood flow, similar to light cardio. Regular sauna use has been linked to lower risk of heart disease and stroke.

2. Promotes Detoxification (Kind Of)

Sweating helps your body eliminate some toxins, but it's not as dramatic as people claim. Your liver and kidneys do the heavy lifting. Saunas just help a little.

3. Increases Heat Shock Proteins

Heat stress activates heat shock proteins, which help repair damaged proteins in your cells. This can improve recovery and cellular health over time.

4. Enhances Endurance

Regular sauna use increases blood plasma volume, which can improve endurance performance. Endurance athletes have been using this trick for years.

5. Reduces Muscle Soreness

Unlike cold, heat promotes blood flow to sore muscles, which can speed up recovery without interfering with muscle growth.

Does Sauna Hurt Muscle Growth?

No. Unlike cold exposure, sauna doesn't interfere with the inflammatory response needed for muscle growth.

In fact, some research suggests that heat exposure might even support muscle growth by increasing heat shock proteins and improving nutrient delivery.

You can sauna after lifting without worrying about blunting your gains.

Contrast Therapy: Cold + Sauna Together

Contrast therapy—alternating between hot and cold—is popular in the recovery world.

The theory: cold constricts blood vessels, heat dilates them. Alternating creates a "pumping" effect that flushes out metabolic waste and brings in fresh blood.

Does it work? Maybe. The research is mixed. Some studies show benefits for reducing soreness; others show no difference compared to passive recovery.

My take: It feels good, and some people swear by it. If you have access to both, try it. But don't stress if you don't—it's not a game-changer.

How to Use Cold Plunge and Sauna for Recovery

Here's my recommendation based on your goals:

If Your Goal Is Muscle Growth:

• Skip cold plunges immediately after lifting
• Use cold on off days or 4-6 hours post-workout
• Sauna after lifting is fine—it won't hurt gains

If Your Goal Is Performance and Recovery:

• Cold plunge after hard sessions to reduce soreness
• Sauna 2-3x per week for cardiovascular and recovery benefits
• Contrast therapy if you have access and enjoy it

If Your Goal Is General Health and Longevity:

• Sauna 3-4x per week, 15-20 minutes per session
• Cold plunge 2-3x per week for mental resilience and mood

Cold Plunge Protocol

If you're going to do cold plunges, here's how:

• Temperature: 50-59°F (10-15°C)
• Duration: 2-10 minutes
• Frequency: 2-4x per week
• Timing: On off days or 4+ hours after lifting

Start with shorter durations (2-3 minutes) and work your way up. Don't force yourself to stay in longer than you can handle.

Sauna Protocol

For sauna benefits:

• Temperature: 170-195°F (traditional sauna)
• Duration: 15-20 minutes per session
• Frequency: 3-5x per week
• Timing: After workouts or on off days

Hydrate before and after. You'll sweat a lot.

Do You Actually Need These?

No. You don't need a cold plunge or sauna to recover or build muscle.

Sleep, nutrition, and smart training are 90% of recovery. Cold and heat therapy are tools that can add 5-10% on top of that—if used correctly.

If you have access to them and enjoy them, use them. If not, don't stress. Focus on the basics first.

The Bottom Line

Cold plunges: Great for reducing soreness and mental toughness, but can interfere with muscle growth if done right after lifting. Use them strategically.

Saunas: Excellent for cardiovascular health, recovery, and longevity. No downside for muscle growth. Use them freely.

Contrast therapy: Feels good, might help recovery, but not essential.

If you want to add these to your routine, go for it. Just don't let them replace the basics: training hard, eating enough protein, and sleeping 7-8 hours.

CJ Critney is a personal trainer and owner of FYTS Fitness in Westlake Village, California, with 13+ years of experience transforming clients through science-backed training and faith-driven discipline.