Roscoe the Iron Intern had a big week.

He did a cold plunge after every lifting session and dropped the converted garage freezer temperature to a frigid 35 F since
1) he does not pay the electric bill,
2) he went on a YouTube Joe Rogan ice bath binge.
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He justified this as going more hardcore for “extra adaptation.”

I told him, as part of his education, to listen to my Expert Interview in the Phys Flex Cert with Dr Fuchs who has researched CWI and muscle hypertrophy in the lab and now Roscoe is fearful that his gainZ went down the drain.

Let’s unpack what is really going on here using……science beooootches!

CWI Vs GainZ

Submerge yourself in cold water right after training and microvascular blood flow to the muscle drops hard and stays down for up to a few hours.

What rides in that blood you ask? Amino acids, and every anabolic signal you just paid for under the bar. Chill your limbs and you throttle the delivery truck right as the construction crew clocks in.

The tracer research work here is not subtle. Fuchs and colleagues (2020) fed people labelled protein after lifting, then cooled one leg and left the other warm — same person, same session, same meal. The cold leg incorporated significantly less of that dietary protein into new muscle, and daily myofibrillar protein synthesis over two weeks came out lower in the cooled condition.

Roberts and colleagues (2015) ran a 12-week training study: the cold-water group gained less strength and less type II fiber size than active recovery, with blunted satellite cell and mTOR signaling.

Fyfe and colleagues (2019) found the same blunted hypertrophy after whole-body resistance training and CWI — though, interestingly, max strength mostly held.

Here is a crash course summary:

Strength findings are mixed.

Regular post-lifting CWI can blunt muscle growth.

Cold is not the villain.

Timing, dose, and how much of your body you shove into the cold all matter significantly as I cover in the Phys Flex Cert pillar 1 on temperature.

Roscoe confused colder, longer, and more with better recovery, which was an error.

Summary

If all-out maximal size is the goal for you or a client, keep cold exposure out of the post-lifting window.

If you love CWI, separate them by several hours (just know we do not have any data on this yet), or park ice baths on off-days and aerobic days, which is my preference.
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I personally love doing CWI and do it post aerobic sessions in the AM and did just that this AM once again.

Want cold for resilience, state control, or just to do one hard voluntary thing before breakfast?

Different job, and a legitimate one!

Here is what aiming it right looks like outside a lab.

Jocelyn Awe, a Director of Sports Performance, sent this to his team after they ran in the rain this week:

“Great job today. Having a mindset to take advantage of the people who shut down over things they cannot control is awesome. Imagine the AC goes out in a humid gym and the other team is complaining about the conditions instead of focusing on the game.
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From a physical standpoint we are creating Physiologic Flexibility. Ever wonder why grandma is always cold?
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People go from air conditioning to air conditioning and lose the ability to regulate body temperature.
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We put our homeostatic regulators to the test so they are robust. In return we recover better and handle more stress than those who live in perfect conditions all the time.”

That is the whole certification in a team huddle.

Stop living in perfect conditions.

Train the regulators.

Get harder to rattle.

Inside the cert, Dave “Iron Tamer” Whitely and I go deep on Wim Hof breathing, cold, and where it genuinely earns a place as he is one of several expert interviews in there in addition to the modules on the 4 pillars for Phys Flex.

You can split it into a much more manageable payment plan at checkout.

>> Phys Flex Certification << open now!

One more thing. The private 1-hour call with me is gone tomorrow night, Wednesday October 14 at 11:59 PM Pacific. It is the best bonus in the stack and the first to leave.

Much love and warm microvascular perfusion,

Dr Mike

PS — don’t just take my word, here is what Dr. Lars Stevenson, Physical Therapist and Trainer of Elite Athletes had to say:

“I have taken everything Mike offers, from the Physiologic Flexibility Certification to the Flex Diet Certification to his HRV course, and I keep coming back for more.

The Physiologic Flexibility Certification does something rare. It takes complex physiology and makes it approachable, and then it packs it into a simple system you can actually use. It is not theory for the sake of sounding smart in front of a client. It is exceedingly practical.

The biggest change in my practice is how I decide what to work on. I now score every option on two things: how much it will change the client’s physiology, and how willing they are to do it as described by his “coaching leverage” concept. A perfect intervention the client will not do is worth very little. A moderate one they will do every day is worth a lot. I run that calculation with every client I see, and I apply it to everything I have learned over the years, not just what Mike taught me (which makes it even more valuable).

What sets Mike apart is that he has real depth and he knows how to teach it. Plenty of people know less than they claim, and plenty of very smart people cannot walk you through the layers of understanding. Mike does both.

If you are a PT, strength coach or personal trainer, take it, especially if other courses left you without a system for putting things into practice. My only wish is that the material he had to cut was available somewhere, because I would take that too.” -Lars Stevenson, PT, DPT

Thanks Dr Lars!!

>> Phys Flex Certification << open now!

References

Fuchs, C. J., Kouw, I. W. K., Churchward-Venne, T. A., Smeets, J. S. J., Senden, J. M., van Marken Lichtenbelt, W. D., Verdijk, L. B., & van Loon, L. J. C. (2020). Postexercise cooling impairs muscle protein synthesis rates in recreational athletes. The Journal of Physiology, 598(4), 755–772.

Roberts, L. A., Raastad, T., Markworth, J. F., Figueiredo, V. C., Egner, I. M., Shield, A., Cameron-Smith, D., Coombes, J. S., & Peake, J. M. (2015). Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training. The Journal of Physiology, 593(18), 4285–4301.

Fyfe, J. J., Broatch, J. R., Trewin, A. J., Hanson, E. D., Argus, C. K., Garnham, A. P., Halson, S. L., Polman, R. C., Bishop, D. J., & Petersen, A. C. (2019). Cold water immersion attenuates anabolic signaling and skeletal muscle fiber hypertrophy, but not strength gain, following whole-body resistance training. Journal of Applied Physiology, 127(5), 1403–1418.

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Mike T Nelson CISSN, CSCS, MSME, PhD
Associate Professor, Carrick Institute
Owner, Extreme Human Performance, LLC
Editorial Board Member, STRONG Fitness Mag

Mike T Nelson is a PhD and not a physician or registered dietitian. The contents of this email should not be taken as medical advice. It is not intended to diagnose, treat, cure, or prevent any health problem - nor is it intended to replace the advice of a physician. Always consult your physician or qualified health professional on any matters regarding your health.

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