Can Cold Immersion in Water Really Impede Muscle Growth?

Get your sweat on, bros! The hype around the icy slip 'n slide, aka cold plunges, is positively sauropod-sized in the fitness community these days. Athletes and self-proclaimed bro-gurus claim these frosty baths can amp up recovery and give your immune system a solid boost. You might've even spotted one overgrown in some dude's backyard, a la Steve Aoki's jacuzzi-jewel.

But the science gods just took a giant spray bottle of reality to this icy trend. A new study from the American College of Sports Medicine has thrown a cold blanket over its benefits, hinting that cold plunges could undermine your rocking gains.

First off, researchers gathered a dozen dudes aged between 20 and 28, pumped them full of iron, and had them straddle two waist-high barrels full of water—one icy and one warm. Then, they gave 'em a protein-carbohydrate beverage—rich in muscle-saving nutrients—both as a snack and with a special amino acid acting as a spy, allowing researchers to track how the nutrition move around their bodies.

Results? A chillin' 30% less nutrition ended up in the icy leg compared to the warm one. Frostbite? No, but cold plunges cause vasoconstriction, which means they shut off blood flow. This blocks nutrients from reaching muscles damaged during exercise, making it tougher for those muscles to repair and grow.

Sure, protein synthesis—muscle repair—continues over a day or two, but the hours right after a workout are peak time for muscle replenishment and growth, says study author Milan Betz from Maastricht University.

What's more, Betz reveals older research also finds that plunging after resistance training for 10 minutes decreased muscle growth after three months versus those who didn't plunge. So, if muscle gains are your goal, you might wanna put your parka away.

However, endurance athletes, like runners or rowers, huffing and puffing after a grueling workout might find that plunging helps them bounce back faster and hit the cutting edge the next day.

Plunging also has a calming effect on the mind, which is why some folks dive into chill waters for the serenity. And some claim cold plunging offers immune-boosting properties. But, let's be real, it ain't settled science.

Can you sip champagne at a world-famous wine tasting and enjoy every drop without getting sloshed? Translation: Can you plunge smartly to enjoy the benefits without negatively impacting muscle growth? Betz admits it might be possible, but there's not enough research to give us an exact number.

"Five minutes of icing can already cause a drop in muscle temperature that may result in some of the negative effects we saw in our study. I reckon one to two minutes won't cause clear issues, at least if muscle growth is your primary goal," says Betz.

So, if maximizing muscle growth is your goal, it's best to stay landlocked until your gains are solid. But if you're an endurance athlete, it might be a useful tool to aid recovery. Just remember, balance is key. Don't jump in like a live-action Looney Tunes scene and risk slipping into hypothermia. Keep it cool, keep it smart.

The new study from the American College of Sports Medicine suggests that cold plunges could undermine your muscle gains by causing vasoconstriction, which blocks nutrients from reaching muscles damaged during exercise.
Milan Betz, the study author from Maastricht University, states that protein synthesis, or muscle repair, continues over a day or two, but the hours right after a workout are peak time for muscle replenishment and growth.
Betz admits that it might be possible to plunge smartly to enjoy the calming effects on the mind and potential immune-boosting properties without negatively impacting muscle growth, but there's not enough research to give an exact number.
Endurance athletes, like runners or rowers, might find that plunging helps them bounce back faster and hit the cutting edge the next day, but it's best to avoid cold plunges if maximizing muscle growth is your primary goal to prevent possible negative effects.