Your 20s and 30s continued...
In terms of your future health, nothing is more important than regular cardio workouts. You can reap benefits from just 20-30 minutes, twice a week, of an aerobic activity like running, swimming, biking, or even dancing, Carmichael tells WebMD: "You will reduce your risk of hypertension, high cholesterol, or even heart attack later in life."
And the sooner you incorporate fitness into your daily life, the more likely you will be to carry the habit into the next several decades.
"It's a lot easier to carry a behavior from one decade to the next, than trying to change a behavior in later years," Carmichael says.
Although she may still feel as powerful and energetic as she did in her 20s and 30s, by the time a woman hits her 40s, her body begins to change. One of the most significant changes is a decrease in hormones that not only affect bones and heart health, but also weight.
"This can help you build new muscle, which in turn will burn more calories and help control weight," says Calabrese. "It can also help put stress on your bones, which will encourage the growth of new bone cells."
She reminds us that "a woman loses at least 5 to 7 pounds of muscle every decade, and that loss begins as early as the 20s." Strength training is one of the only ways to compensate, she says.
Among the best strength-training workouts, she says, is lifting weights. And she advises you to do your lifting while standing, not sitting: "This gives you an added edge and turns a muscle-building exercise into a bone-strengthening exercise."
If you spend a lot of time in high heels, or if you're concerned about knee problems, your workout should include exercises to strengthen your thigh muscles, or quadriceps, says Litman, a rheumatologist.
"If you start in your 30s and 40s to keep these muscles aligned and strong, you will avoid many mobility problems in your later years," says Litman, a clinical assistant professor at Georgetown University in Washington.