Calcium: “Getting enough calcium is important for all ages, but it's particularly important during adolescence and early adulthood, when bones are absorbing calcium,” says Heather Schwartz, MS, RD, a medical nutrition therapist at Stanford University Hospital and Clinics. Calcium and vitamin D are often paired in fortified foods such as milk. The reason: The body needs D in order to absorb calcium.
Having the proper footwear is essential for any workout, and for winter runs, that means sneaks with EVA (ethylene vinyl acetate), says Polly de Mille, an exercise physiologist who oversees New York Road Runner's Learning Series for first-time New York City Marathon runners. “Polyurethane tends to get really stiff and cold in the winter, which could increase your risk of injury.” Another important feature is a waterproof and windproof upper: Look for shoes made with Gortex, or wrap your mesh uppers in duct tape to keep feet dry and warm.
Fluids: Fluid needs increase as women age. The reason: Kidneys become less efficient at removing toxins. “Drinking more fluids helps kidneys do their job,” Schwartz says. “Unfortunately, thirst signals often become impaired with age, so people are less likely to drink enough water and other fluids.” Rather than fret about how many glasses to drink, Frechman says, check the color of your urine. "It should be clear or very pale colored. If it becomes darker, you need more fluid.”