If you usually head to the gym after work, take heed: Mental exhaustion can make you feel physically exhausted, even when you have plenty of energy, reports a Medicine & Science in Sports & Exercise study. When people played a brain-draining computer game before exercising, they reported a subsequent workout as being harder, yet their muscles showed the same activity as they did doing the same workout after an easy mental game. So if you think you can’t eke out those last 10 minutes on the rowing machine, remember: You can! [Tweet this motivation!]
A person's caloric requirement depends on his body size and exercise level. Sedentary people of both genders will keep their weight stable by taking in about 13 calories per pound of body weight each day. Moderate physical activity boosts this requirement to 16 calories a pound, and vigorous exercise calls for about 18 calories a pound. On average, a moderately active 125-pound woman needs 2,000 calories a day; a 175-pound guy with a similar exercise pattern needs 2,800 calories. And like women, men will lose weight only if they burn more calories than they take in.

As the table above shows, some of the best sources of calcium are dairy products. However, dairy products such as whole milk, cheese, and yogurt also tend to contain high levels of saturated fat. The USDA recommends limiting your saturated fat intake to no more than 10% of your daily calories, meaning you can enjoy whole milk dairy in moderation and opt for no- or low-fat dairy products when possible. Just be aware that reduced fat dairy products often contain lots of added sugar, which can have negative effects on both your health and waistline.

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.”