Cold Immersion Is Even More Worthless Than We Thought? (New Study)

Israetel reiterates the well-established negative effect of cold immersion on muscle growth, citing previous literature. He explains that this is not new, but it serves as the foundational trade-off in the debate. The meta-analysis focuses on performance, but the hypertrophy blunting is a separate, robust finding. He frames the advice starkly: if you care at all about muscle growth, cold immersion post-workout is out. He suggests that if someone absolutely insists on cold plunging for psychological or other reasons, they should do it hours after training, but that is a compromise, not an endorsement. The overall message is that the practice directly opposes the training goal for hypertrophy-focused individuals, and now that the performance recovery justification is gone, there is no remaining upside to outweigh this harm.

This is the central protocol derived from the episode’s main argument. Israetel spends considerable time walking through the meta-analysis design and findings to justify this shutdown of the performance recovery narrative. He highlights that the studies included real sports scenarios, not just lab metrics, and that the null effect was consistent across temperature, duration, and immersion depth. He emphasizes that the rationale for cold immersion in elite sport—quick turnaround between games or events—is exactly what this data tested and found wanting. The protocol is blunt: stop using cold immersion for recovery. He acknowledges the psychological difficulty of letting go of a practice that ‘feels’ helpful, but insists that the science has turned. The only defensible use he now leaves open is for those who simply enjoy the feeling with no expectation of objective performance gain, and even then, only if they are not worried about hypertrophy.

Israetel makes a nuanced allowance for those who really love cold plunging. He acknowledges that the data do show less soreness, and if that helps someone feel better mentally, it’s not completely worthless. He repeatedly draws the line between ‘feeling less sore’ and ‘being more recovered,’ which many in the fitness industry have conflated. He uses the term ‘vibe’ to describe the practice when stripped of its performance claims. This protocol is for the individual who decides the psychological benefit is worth the hassle and the potential slight hypertrophy blunting (if timed poorly). He even jokes that it’s ‘for psychological punishment,’ hinting that it may serve a mental toughness or routine function. The key is to be honest about what you’re getting.

The speaker mentions this idea almost in passing as a way to accommodate the few people who refuse to give up cold plunging. He offers no guarantee it will preserve muscle gains entirely, but suggests it could at least avoid the immediate post-workout window where interference is strongest. Given his overall tone, this is less an active recommendation and more a damage-control measure for the cold-plunge faithful. There is no deep dive into timing specifics, so it remains a suggestion rather than a firm protocol.

The meta-analysis pooled 30 randomized controlled trials where participants either cold immersed or used a placebo/control after exercise, then measured performance outcomes like strength and countermovement jump height. The exercises tested were extremely varied—HIIT, conventional resistance training, endurance running, rugby, basketball, BJJ, 10 km downhill runs, even half marathons—covering a wide range of real-world athletic scenarios. The authors applied a publication bias correction, and while they initially saw a reduction in creatine kinase (a muscle damage marker), that effect mostly disappeared after correction. Subjective soreness was modestly reduced, but objectively, neither strength nor jump performance rebounded better than in control groups. Interestingly, partial or lower-body immersion performed just as poorly as whole-body immersion, underscoring that the intervention lacks a dose-response effect. The overwhelming majority of participants were male, so conclusions for females are limited. Dr. Israetel notes that individual responders may still exist, but the average null effect is robust enough to change practice. He explicitly states that this review marks the end of the practical justification for using cold immersion as a performance recovery tool.

Dr. Israetel directly addresses the cognitive dissonance: people knew cold immersion blunted hypertrophy, but they clung to the performance recovery story. He walks through the hypothetical use case—a soccer tournament where you play multiple games and want to stay loose—and says the meta-analysis shows that even in such situations, cold immersion does not meaningfully preserve strength or power. He admits that some individuals may feel better and maybe get a benefit, but the average data tells a clear story of no meaningful effect. This leads him to conclude that any recommendation to use cold immersion for performance recovery is now unsupported. He encourages listeners to rethink their habits and distinguish between a science-backed practice and a 'vibe' or psychological comfort ritual. He doesn’t rule out cryo chambers or local icing definitively, but given the mechanistic similarity, he’s skeptical. The take-home is unambiguous: if you’ve been cold plunging to recover for your next training session or competition, the rug has been pulled.

Israetel explains that the meta-analysis found a reliable small effect on reported soreness, but no improvement in strength or jump performance. The creatine kinase reduction, which could have hinted at less muscle damage, disappeared after statistical correction for publication bias, meaning we can’t even be sure there is less actual muscle damage. This uncouples the subjective experience from objective repair. He emphasizes that this is crucial for practitioners who equate feeling better with being ready to play. For sports with rapid competition turnaround, relying on cold immersion to stay fresh is likely a placebo at best. He doesn’t dismiss the value of feeling good—if psychologically it helps, fine—but cautions against expecting a real performance edge.