#competitiveswimmer

At 6:45 a.m., with temperatures in the 30s, I step onto the outdoor pool deck at the Bethesda-Chevy Chase YMCA, a towel draped over my shoulders. The sky is adorned with pink streaks, and the moon is still visible. A layer of steam hovers over the heated water as I immerse myself and start swimming, the contrast of crisp air and lukewarm water creating a thrilling sensation.

To some, the idea of swimming outdoors in near-freezing conditions may seem crazy, but experts assure that winter swimming in a heated pool is safe and beneficial for health. For the dedicated community of winter swimmers joining me each day, there's nothing quite like the experience.

Massage therapist Valerie Campbell from Kensington, Md., who swims outside at the Y five mornings a week year-round, attests to the invigorating feeling: "It's a joy to feel so refreshed. We enjoy the sunlight, the mist over the water, even the brisk wind at times, which can cool the soles of our feet as we kick. Sometimes, indoor swimmers venture out, but they never last long."

Outdoor winter swimming can also be a spectacle. Financial analyst Robert Judson from Bethesda, Md., recalls a particularly memorable evening swim: "It was a bitterly cold night with the stars out. It started snowing lightly halfway through my usual leisurely mile. It was magical. Perhaps too magical. Maybe it was a dream."

While non-swimmers and even those who prefer indoor swimming may not fully understand the allure of winter swimming, they appreciate the enthusiasts. Professor Kate Macomber Harsh, who swims indoors at the B-CC Y, expresses gratitude: "I'm actually glad that there are so many nuts who love swimming outside. That makes the indoor pools much less crowded."

Despite the exhilarating feeling, experts note that, from a health perspective, swimming in a heated outdoor pool provides no additional benefits compared to indoor swimming. The calorie burn remains unaffected by cold air, but swimming in cold water can increase the calorie expenditure if shivering is added to the activity.

In the warm waters of the B-CC Y outdoor pool (usually maintained between 80 and 83 degrees), the risk of hypothermia is minimal when swimmers are in motion. Unlike in unheated outdoor waters, a swimmer's body fat percentage is less critical in heated pools.

According to Mike Tipton, a professor of human and applied physiology, shivering disappears during exercise at an intensity above "light activity." In the B-CC Y's outdoor pool, where the water is kept comfortably warm, there is little danger of hypothermia.

Swimmers should distinguish between water and air temperatures, as the cool air becomes a non-factor once submerged. Scott Trappe, head of the human performance laboratory at Ball State University, emphasizes, "You stay submerged. It's perfectly fine. It's fantastic, in fact."

Different swimmers have varying preferences for water temperature. Slower swimmers may find an 82-degree pool ideal, while faster swimmers like Anna Alberini, an economics professor, prefer water cooler than 80 degrees but not below 70.

When the water temperature drops into the 70s or lower, the risk of hypothermia increases. This is why many open water swimmers train in heated outdoor pools during the winter.

Swimmers should take precautions and acclimate gradually when the water temperature is below 70 degrees. Michael J. Joyner, a physiologist at the Mayo Clinic, advises, "If the temperature is under 70, get in for a few minutes today, then a few minutes tomorrow, and so on."

Both the B-CC and Silver Spring YMCA facilities offer year-round outdoor swimming. Lifeguards, dressed in warm clothing, rotate every half-hour and have a heated shack to protect them from the cold, wind, and rain. The pool closes when the temperature drops below freezing or the wind chill falls below 25 to prevent accidents on the icy deck.