Taking the Plunge: Cold Baths After Training - Help or Hindrance?

Cold water immersion - whether it’s a 10-minute ice bath, cold plunge, or a post-run ocean dip, has long been part of the recovery toolbox for endurance athletes. From Ironman triathletes to marathoners and cyclists, the practice is seen as a way to bounce back faster, reduce muscle soreness, and prepare for the next hard session.

But recent research reveals a more complex picture. While cold exposure can support short-term recovery, it might also blunt long-term training adaptations, especially those related to muscle growth and strength when used immediately after resistance training.

So, should cold plunges be part of your recovery protocol? Or could they be counterproductive depending on your goals?

What Is Cold Water Immersion?

Cold water immersion (CWI) is the practice of submerging the body (or lower limbs) in cold water, typically between 10°C and 15°C (50–59°F) for 10–20 minutes, usually after training. It’s not new: elite athletes have been using CWI for decades to accelerate recovery and manage training load.

CWI is thought to:

• Reduce post-exercise muscle soreness (DOMS)
• Lower core body temperature
• Decrease inflammation and swelling
• Improve autonomic nervous system recovery
• Lessen perceived fatigue

With the explosion of wellness content and social media, “cold plunging” has gone mainstream but the evidence shows that timing and context are key when deciding if it’s a good fit for your training.

The Benefits: How Cold Can Help

When used appropriately, cold water immersion has several well-supported physiological benefits, particularly for aerobic athletes managing volume and frequency.

Known short-term benefits:

• Reduced muscle soreness after long runs, rides, or bricks
• Faster recovery between sessions
• Temperature regulation, especially in hot climates
• Decreased cardiovascular and metabolic stress
• Improved perceived readiness, which may support adherence and motivation

These benefits are especially useful during intense training weeks, races in hot conditions, or multi-day endurance events.

In a practical sense, many athletes report feeling “fresher” or “lighter” after a post-session cold plunge. This psychological recovery component shouldn’t be dismissed, improved perception of recovery can influence training quality and consistency.

 

The Costs: Where Cold May Hurt Progress

Recent studies raise concerns about cold water immersion immediately following resistance or strength training.

Key findings:

• A 2024 meta-analysis of 10 randomised control trials found that CWI reduced muscle strength gains when performed after resistance training.
• A 2023 meta-analysis in the European Journal of Sport Science reported that cold water immersion modestly attenuated hypertrophy (muscle growth) over time compared to training without cold exposure.

These reductions were small but consistent, regardless of:

• Participant training status (trained vs untrained)
• Program length (under or over 8 weeks)
• Frequency (2–3 strength sessions/week)
• Type of resistance training (single muscle group or whole-body)

This doesn’t mean cold plunging prevents muscle growth. Only that it diminishes gains slightly when used immediately after strength-focused sessions.

Why Does Cold Water Reduce Muscle Gains?

Muscle growth and strength gains depend on a cascade of physiological processes triggered by resistance training, including:

• Micro-tearing of muscle fibres
• Acute inflammation and swelling
• Blood flow and nutrient delivery
• Activation of anabolic pathways like mTOR
• Elevated muscle protein synthesis (MPS)

Cold water may interrupt this cascade by:

• Blunting inflammation needed for muscle repair
• Constricting blood vessels, reducing delivery of amino acids, oxygen, and hormones
• Suppressing anabolic signalling, which dampens MPS response

While this is not a concern for low-intensity aerobic efforts, blunting these pathways right after lifting could inhibit the muscle-building effect you're aiming for.

Does It Impact Endurance Athletes Differently?

The good news for endurance athletes is that cold exposure does not interfere with cardiovascular or mitochondrial adaptations. In fact, some evidence suggests it may even enhance key endurance traits.

For endurance-focused training:

• Cold water immersion does not inhibit VO₂ max improvements
• It may enhance mitochondrial biogenesis, improving aerobic efficiency
• It can reduce thermal strain, especially during back-to-back sessions or in tropical climates

That makes CWI a valuable tool for:

• Recovery from long aerobic sessions
• Cooling the body post-race or post-workout
• Supporting consistent training load

If your primary goal is to improve endurance capacity, strategic use of cold exposure can aid rather than hinder your progress.

Cold Exposure and the Nervous System

Cold immersion also appears to influence the autonomic nervous system, particularly the parasympathetic (rest and digest) arm. This may help accelerate post-exercise recovery and contribute to improved sleep, reduced stress, and better mood.

Emerging research also points to CWI’s role in:

• Lowering heart rate variability (HRV) more quickly post-exercise
• Stabilising cortisol levels
• Promoting better sleep when used earlier in the day

For athletes under high training or life stress, these effects may make CWI a valuable tool even outside of direct performance outcomes.

 

Practical Guidelines for Cold Water Use

To maximise benefits and minimise drawbacks, consider these science-based recommendations.

When to Use Cold Water Immersion:

• After long aerobic sessions, particularly in hot conditions
• During taper weeks to stay fresh without adding volume
• When managing training load spikes or soreness
• Between race stages or double-session days
• For nervous system reset (e.g., stressful days, poor sleep)

When to Be Cautious:

• Immediately after heavy resistance or hypertrophy sessions
• During off-season strength blocks
• When prioritising power or muscle mass gains
• If your nutrition and sleep are already suboptimal, which are more critical recovery factors

Timing Tip:

If you're committed to both strength and endurance, consider separating your cold exposure by at least 4–6 hours post-resistance training. This allows muscle-building signals time to activate before introducing the cold.

Alternatives to Cold Water Immersion

If you're hesitant to use CWI post-strength training but still want recovery support, consider:

• Compression garments for circulation support
• Active recovery like low-intensity cycling or swimming
• Contrast baths (alternating hot and cold)
• Optimising carbohydrate and protein intake post-session
• Sleep hygiene and stress management techniques

These tools can be effective without interfering with training adaptations, especially when combined with sound nutrition and a consistent routine. 

Should You Be Cold Plunging? A Grounded Conclusion

Cold water immersion is neither a miracle nor a mistake - it’s a tool. Used at the right time and for the right purpose, it can absolutely help endurance athletes recover faster, stay consistent, and reduce training fatigue.

But it’s not universally beneficial. If you’re lifting heavy and want to build strength or lean mass, cold exposure immediately after training could blunt those adaptations. In that case, let your body recover naturally, and save the plunge for later in the day or after endurance sessions.

Ultimately, the best recovery method is the one that supports your specific training goals, fits your routine, and aligns with your body’s signals.

 

 

 

References

Poppendieck W, Wegmann M, Ferrauti A, Kellmann M, Pfeiffer M, Meyer T. Does Cold Water Immersion Attenuate Post-Exercise Muscle Hypertrophy and Strength Gains? A Systematic Review and Meta-Analysis. Eur J Sport Sci. 2024.

Ihsan M, Watson G, Abbiss CR. What Are the Physiological Mechanisms for Post-Exercise Cold Water Immersion in the Recovery from Prolonged Endurance and Intermittent Exercise? Sports Med. 2016.

Roberts LA, Raastad T, Markworth JF, et al. Postexercise Cold Water Immersion Attenuates Acute Anabolic Signaling and Long-Term Adaptations in Muscle to Strength Training. J Physiol. 2015.

Fyfe JJ, Bishop DJ, Stepto NK. Interference between concurrent resistance and endurance exercise: Molecular bases and the role of individual training variables. Sports Med. 2014.