What is a mechanism by which an ice bath can aid recovery?

• A. Increases swelling
• B. Vasodilation during immersion
• C. Raises lactic acid levels
• D. Vasoconstriction during immersion

Answer: (D)

Cold-water immersion helps recovery mainly by constricting the blood vessels in the immersed area. The cold lowers tissue temperature, which reduces metabolic rate and makes capillaries less permeable, so less fluid leaks into the surrounding tissue. This vasoconstriction limits swelling and inflammation, which can reduce pain and the risk of secondary tissue damage, helping the recovery process.

Sometimes, after you get out and the body warms up again, blood flow returns with a flush of nutrients and waste products being cleared more efficiently, but the immediate recovery mechanism during the ice bath is the vasoconstriction that reduces swelling and inflammatory responses.

The other ideas don’t fit with how cold immersion works: it doesn’t increase swelling or promote vasodilation during immersion, and it doesn’t raise lactic acid levels.