The workout + cold plunge combo doesn’t actually help gains, per new research

Not to throw cold water on anyone’s routine: but if you’re looking to build muscle, frigid baths immediately after a workout just ain’t it, according to a study recently published in the journal Medicine & Science in Sports and & Exercise.

Shrinking properties

As part of the study, the researchers had a dozen healthy young men perform a leg workout. Once finished, each participant immediately submerged one leg in a bucket of warm water (80°F) and another in a bucket of icy water (30°F) for 20 minutes.

• To test the gainz, the men were given a protein shake containing a biochemical tracer, which allowed the researchers to track the protein as it traveled in the volunteers' bloodstreams.
• Ultrasound imaging revealed that blood flow in the cold-plunged leg was considerably lower than that of the warm leg, and stayed that way for hours. This constriction cut off a lot of protein from reaching the strained leg muscles, reducing muscle-building.

But…The new research is a small study, focused specifically on strength gains (though it tracks with other data on this topic). It’s also unclear whether and how timing and other details matter—cold plunging hours after a workout instead of immediately, for example.

Zoom out: Previous research has shown post-workout cold plunges can provide beneficial anti-inflammatory properties for aerobic athletes like runners, soccer players, and swimmers, as well as small reductions in stress and improvements in sleep quality.