A few tweaks to your routine can make getting outside more comfortable this season.. With cold weather, icy streets and shorter days, it’s easy to find an excuse to stay inside during the winter months. That’s presumably why Americans on average get about half an hour less daily physical activity at this time of year.. But not everyone has a choice. Elite winter athletes and military personnel in northern postings stay active no matter how low the mercury drops — and the scientists who work with them continue to learn new things about how to do so safely, effectively and even comfortably.. Here’s what their latest findings can teach the rest of us about staying active outdoors through the winter.. You will get used to the cold.. The good news is that your perception of temperature changes with the seasons. “When we get that first bit of cold air, it feels awful,” said John Castellani, a physiologist at the U.S. Army Research Institute of Environmental Medicine in Massachusetts. “And then in March, you get that same temperature and it feels like it’s time to go play golf.”. These changes start happening within about ten days of exposure, Dr. Castellani said. But they’re only skin deep: You feel less cold, but for the most part you don’t get any better at keeping your core temperature up or your extremities warm.. Military researchers have gone to great lengths trying to help soldiers adapt to winter weather, with little success. A few people — the polar swimmer Lewis Pugh, for one — have demonstrated extraordinary cold tolerance, but they seem to be outliers. “I don’t dispute what they can do,” said Stephen Cheung, an environmental physiologist at Brock University in Canada. “But I don’t think there are lessons that we can learn from them and apply to ourselves.”. We are having trouble retrieving the article content.. Please enable JavaScript in your browser settings.. Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.. Thank you for your patience while we verify access.. Already a subscriber? Log in.. Want all of The Times? Subscribe.