Fasted workouts and low-carb diets are trendy, but they're the wrong strategy in this case, Gende says. Your muscles shiver in the cold, thereby increasing your body’s heat production five-fold—but to do it, you need carbs in your system. She suggests eating cereal, raisins, or a sandwich one to four hours before you head onto the water.
How much you'll need depends on several factors like exercise intensity and duration; at the very least, eat one gram of carbs per kilogram of body weight (59 for a 130-pound woman, 82 for a 180-pound man), per the American Academy of Sports Medicine. Pack high-carb snacks like granola bars or energy gels, too. "Use what you're familiar with and play around with volume to find your sweet spot," Gende says.
Move through a 10- to 20-minute routine until you're a touch out of breath and your skin is borderline moist, Gende says. Your flow will further prepare you for the activity if it activates the muscle groups and firing patterns you'll use on the water.
Before climbing on her paddleboard, Sykes builds heat through exercises like jumping jacks and arm swings. There’s no one-size-fits-all warm-up, but you could cycle through 1 minute each of those two moves plus high knees, push-ups, and burpees, completing 2 to 4 rounds. A light jog will also do, Gende notes.
When cold water splashes inside your ears, it can affect your equilibrium and make you more likely to lose your balance, Gende says. Some winter kayakers wear earplugs, though hearing is key for safety. She suggests a thick hat with full coverage instead.
In fact, keep your whole body as dry as possible; in cold water, you can lose up to 1.8 degrees Fahrenheit every five minutes. That’s seventy times faster than the heat loss you can experience in cold air. As much as possible, avoid rapids and unfamiliar waters. If you do get wet, dry off and change into fresh clothes immediately, then apply heat packs strategically. Speaking of...
Heat tends to escape from the groin, armpits, top of the head, and base of the neck. "That’s why you stick your hands under your arms to warm them,” Gende explains. Trapping heat in these regions with a heat pack or pad raises your body temperature overall.
While the heat warms your body from the inside, sugar powers your ability to maintain that higher temp, Gende says. You won’t get the second benefit from liquids like coffee, tea, or broth. Sykes balances a small camping stove and kettle on the end of her paddleboard for fresh hot chocolate, but an insulated Thermos also works.