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The science of ice plunges with Chris Ballard | ReThinking

Many people regularly plunge into ice-cold water to soothe soreness or boost energy—but for some, the plunge itself is a sport. As a sports journalist, Chris Ballard was reporting on cold water immersion when he got into ice swimming himself and ended up competing on the US team at world championships. In this episode, Adam dives into Chris’s book The Plunge, and the two discuss the psychology behind risk taking, endurance, and resilience in the face of discomfort. They explore why people seek out extreme challenges that push their minds and bodies to the limit, and separate myth from science about the health benefits of cold water immersion. Follow our podcasts! ReThinking with Adam Grant: https://link.mgln.ai/kdYcyx The TED Podcasts is a collection of podcasts for the curious. The TED Podcasts videos may be used for non-commercial purposes under a Creative Commons License, Attribution–Non Commercial–No Derivatives (or the CC BY – NC – ND 4.0 International) and in accordance with our TED Talks Usage Policy (https://www.ted.com/about/our-organiz...). For more information on using TED for commercial purposes (e.g. employee learning, in a film or online course), please submit a Media Request at https://media-requests.ted.com.

Chris BallardguestAdam Granthost
Jul 30, 202634mWatch on YouTube ↗

At a glance

WHAT IT’S REALLY ABOUT

Cold plunges explained: science, benefits, limits, and how to start

  1. Cold exposure appeals to different people for different reasons—extreme challenge, community bonding, and mental-health-focused stillness—often delivering a strong sense of presence and shared accomplishment.
  2. People’s reactions to cold vary meaningfully due to genetics and physiology (“warmies” vs. “coldies”), but acclimation can occur quickly with repeated exposure for many individuals.
  3. The strongest evidence-supported benefits Ballard cites are modest athletic recovery, a short-term mood boost and calm-alert state driven by neurochemicals, and potential resilience/mental health effects that may be confounded with community and outdoor activity.
  4. Ballard’s personal experience includes improved resting heart rate/HRV and better emotional regulation, which he attributes partly to repeated “daily tests” of controlled discomfort.
  5. Because rigorous research is limited and social media claims are inflated, Ballard recommends simple, strategic protocols (e.g., brief cold showers) and prioritizing safe, social, sustainable practice over extremes.

IDEAS WORTH REMEMBERING

5 ideas

Cold tolerance is partly innate, but often trainable.

Ballard describes “warmies” and “coldies” as a genetic/physiological split, yet notes many people acclimate within about a week of repeated exposure, moving faster through the unpleasant phase.

The ‘why’ isn’t just biohacking—it’s often social and psychological.

Beyond performance goals, Ballard saw strong community effects (“peer positive pressure” and a ‘shared crisis’ bond) and a mental-health draw: reliably creating stillness and a sense of self-efficacy.

The most defensible benefits are narrower than hype suggests.

Ballard’s reporting suggests evidence is strongest for modest soreness/recovery help, a short-lived mood boost, and a calm-alert state; broader claims circulating online outpace the research base.

Staying in ~90 seconds can shift panic into calm.

He reports that the initial fight-or-flight surge can give way to a calmer preservation mode after about 90 seconds, aligning with the ‘alert but calm’ experience many plungers describe.

Use cold exposure as ‘productive stress’—but only if dread doesn’t dominate.

Ballard notes some athletes enjoy it as eustress, while others’ anticipatory stress overwhelms any payoff; if fear/dread is too high, benefits may not be worth the emotional cost.

WORDS WORTH SAVING

5 quotes

And that experience was so cold, it could feel- ... like fire.

— Chris Ballard

One of the thermal physiologists I spoke to, he said essentially we're divided into what he called warmies and coldies.

— Chris Ballard

And, and that experience is part of what some of these people chase, is getting to that point where you've almost scrambled all your body's signals, and so there's a, a certainly a sense of you are fully in the moment. You are fully present because your body has no idea what's going on.

— Chris Ballard

It's a feeling of, "Here's something I can do that reliably makes me feel good about myself and reliably makes me feel good about the people I'm doing it with."

— Chris Ballard

It is not the confidence that leads to action, it is the action that leads to confidence.

— Chris Ballard

Ice swimming vs. cold plunging vs. cold showersGenetic/physiological differences in cold toleranceAcclimation and learned adaptationMotivations: challenge, identity, community, mental healthPhysiological responses: fight-or-flight, dopamine/noradrenaline, calm after ~90 secondsEvidence and limits of research on benefitsPractical regimen and behavior-change psychology (peak-end rule, sustainability)

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