To pick up your pace, pump up the iron. In a recent Cornell University study, women who had low levels of the nutrient in their blood (but weren’t technically anemic) rowed more slowly than athletes with healthy amounts of it. “Aim to get 18 milligrams of iron daily,” says lead researcher Diane M. DellaValle, Ph.D., R.D. “Any less can decrease your endurance and affect how efficiently your body uses energy.” To perform at your peak, incorporate iron- rich foods like lentils (7 milligrams per cup), spinach (6.5 milligrams per cup, cooked), and lean beef (6 milligrams for 6 ounces) into your diet.
For maximum benefits steam or sauté your veggies— your body absorbs the iron in dark, leafy greens more easily when they’re cooked.