\n\n\t\tAdvertisement - Continue Reading Below\n\t\n\nAsk any runner, and they\u2019ll tell you their favorite time of year to train. For most, it\u2019s the cooler months of spring and fall (hello, race season!), when all you have to do is throw on a tank and leggings or shorts and you can run comfortably for miles. But even when the temperature feels great\u2014some people love the crisp cold of winter or even the dry heat of summer\u2014variables like humidity, wind, and rain can throw off you wardrobe game, leaving you stressed about overheating or freezing your butt off before you even walk out the door. Remember, no matter what the temperature says, your body is going to heat up as soon as you start moving. A solid rule of thumb: Dress like it\u2019s 15 to 20 degrees warmer than it actually is. \u201cYou should be uncomfortable standing outside as you wait for your watch to sync,\u201d says Elizabeth Corkum, a master trainer at Mile High Run Club in New York City. \u201cIf you\u2019re fine simply standing outside, the odds are good you'll overheat once you warm up into your run.\u201d The ideal temperature for marathon running, by the way, is 45\u00b0F, according to research published in the journal PLOS One. \u201cIf you\u2019re going all out for that long at that temperature, you're generating so much heat that the cool air environment allows you to be the most efficient,\u201d says Doug Casa, Ph.D., Chief Executive Officer of The Korey Stringer Institute, which provides research on exertional heat stroke prevention. The less speed and intensity you have, the higher the temp (typically in the 50s or 60s) you\u2019ll feel most comfortable at. Take the guesswork out of getting dressed with this clever tool, which will recommend the right gear for you no matter what the conditions are outside. Not sure if you need that jacket or vest, or can\u2019t decide between a tank or tee? We\u2019ve got you covered, from sunglass recs right down to your shoes.