I’m a regular six-day-a-week exerciser and a fan of strenuous cardio workouts along the lines of hill sprints, running, high-intensity interval training and jump rope. But I find it difficult to exercise when the temperature rises above 65 degrees Fahrenheit. I get too sweaty, overheated and sluggish.
Even the air-conditioned gym in my apartment building isn’t cool enough. I need to be surrounded by two floor fans to move hard the way I like to and crave chilly fall and winter days when I can exercise outside in 40-degree or cooler weather. Summer, needless to say, is my least favorite time to get my cardio fix in.
Over the years, plenty of people, including my husband, have told me that I’m eccentric. But there is some evidence that cool temperatures support an increase in exercise performance and fat burn.
Late last summer I started going to Brrrn, a Manhattan exercise studio where all the classes are held in a room kept at 50 degrees Fahrenheit, based on the idea that cool temperature exposure improves endurance and burns more calories than an ambient or heated environment.
An instructor known as Cake leads participants through cardio and weightlifting circuits.CreditDolly Faibyshev for The New York Times
The studio’s founders and owners, Johnny Adamic, who worked on Mayor Bloomberg’s obesity task force, and Jimmy Martin, a certified personal trainer and former college wrestler, said that the idea to open their cool temperature studio in 2013 came from Mr. Martin’s experience training a client. “We were in a gym where it was pretty hot, and she got faint and had to stop,” Mr. Martin said. “She told me that she was from Boston and loved exercising in cold weather because she found it easier.”
As a former wrestler used to competing in matches in non-air-conditioned settings, Mr. Martin had long thought that profuse sweat equaled a more challenging workout. “I was intrigued by her reaction to the heat and by what she said but started researching cold temperature workouts and found lots of evidence to support how she felt,” he said.
Dr. Ira Jacobs, a professor of kinesiology at the University of Toronto, for one, has researched the phenomenon of cold weather workouts and found that people can exercise for longer and harder, and thereby burn more calories, if they can slow down the rate at which their body temperature increases.
“When you work out, you produce heat, but your rate of perceived exertion is less when it’s colder, making exercise seem easier,” he said.
And a 2013 report in the Journal of Clinical Investigation, led by professors at Maastricht University Medical Center in the Netherlands, states that “regular exposure to mild cold may provide a healthy and sustainable alternative strategy for increasing energy expenditure.”
Ray Cronise, a former NASA scientist, has studied mild cold stress and health span and said that humans not only burn more calories while they’re exposed to cold temperatures, they continue to do so for hours afterward.
Harley Pasternak, a Los Angeles-based personal trainer who studied the impact of the environment on exercise when he worked as an exercise physiologist for the Canadian military, said that humans burn more calories in colder climates because the body has to work harder to create heat. “In a warm environment, your metabolism gets slower so that your core temperature doesn’t overheat,” he said.
Mr. Pasternak’s sprawling training facility in Los Angeles has a room with a treadmill where the thermostat is set to below 59 degrees. “When my trainers or I have clients on calorie-burning programs, we often have them go in there for cardio sessions because it’s not as much of a strain for them to really push themselves,” he said.
In his role as the global fitness adviser for Four Seasons Hotels and Resorts, Mr. Pasternak said that he is looking to incorporate elements of temperature manipulation in the brand’s gyms, which would mean having heated rooms ideal for yoga and stretching and cold rooms for fat burning.
Of course, some people like stretching and sweating in hot yoga studios, and may have trouble warming up to the idea of chilling.
Most gyms have their thermostats set to between 68 and 72 degrees. But Christopher Minson, head of the department of human physiology at the University of Oregon who has done numerous studies on exercising in high heat and heat acclimation workouts, said that this temperature range is too warm for endurance workouts such as intense cardio sessions. “It’s true that endurance performance diminishes in temperatures higher than 50 degrees,” he said.
“You might feel chilly when you start, but you will warm up fast,” he said. “If it helps you work harder, you will burn more calories.”
Stephen Kaminsky, a Chelsea resident who works in the finance industry, takes two to three classes a week at Brrrn and said that he can noticeably push himself harder, compared with when he is exercising in a warmer setting. “Instead of lifting 25 pounds overhead, I do 40 pounds,” he said.
Lindsay Koffler, a graphic designer who lives in the East Village, is a regular, too, and said that, thanks to the cold room, she no longer dreads doing burpees. “I used to despise them but now, I can get through 20 of them- twice as many as normal- and still feel energized after,” she said.