Actress Zendaya has stated she has no interest in the popular cold plunge wellness trend, preferring long, hot showers instead. This preference aligns with the advice of exercise physiologist Dr. Stacy Sims, who suggests that women may not experience the same benefits from immersing themselves in icy water as men do.
Cold plunging involves submerging oneself in water between 50 and 60 degrees Fahrenheit for one to five minutes. Proponents claim it can aid muscle soreness recovery by constricting blood vessels, potentially reducing swelling and inflammation. Some studies also suggest possible mental health benefits, such as reduced stress and improved focus, as well as preliminary evidence for immune system support.
However, Dr. Sims argues that cold water triggers a more significant stress response in women than in men. She posits that instead of promoting metabolic benefits, the shock can push a woman's body into a shutdown phase by activating the sympathetic nervous system. Sims attributes this difference to women generally having more body fat and a greater reliance on vasodilation and vasoconstriction for temperature regulation.
Research on gender differences in cold exposure yields mixed results. A 2020 study noted no significant differences in short-term thermogenic responses between young men and women, though some metabolic and hormonal changes appeared more pronounced in women, indicating a potential sex-specific reaction. A separate 2025 analysis found that men, but not women, reported improved sleep after cold baths.
Sims suggests that heat exposure, such as through saunas, might be a more beneficial approach for women. She notes that women tend to tolerate heat better and that their bodies respond to sauna heat by producing heat shock proteins, which can protect cells from stress and aid in cellular repair. These proteins may improve how muscles utilize glucose and fat for energy.
Furthermore, heat exposure can enhance blood flow to the brain and improve the efficiency of blood vessel constriction and dilation. This is particularly relevant as women approach perimenopause and may become more susceptible to high blood pressure. Women's bodies also regulate heat differently, widening blood vessels to release heat before sweating, which can allow for better adaptation to higher temperatures and potentially reduce physiological stress.
According to Sims, these physiological differences may explain why women can tolerate heat better than men. Regular sauna use, a minimum of 10 to 15 minutes twice a week, is suggested to offer cardiovascular health benefits, including improvements in blood flow, blood pressure, blood glucose control, and fat metabolism. Studies also indicate that combining regular exercise with sauna sessions may enhance cardiorespiratory fitness.