Aerobic exercise boosts breathing, circulation, and heart rate. It also shifts your metabolism away from storing to burning fat, and it’s been found to improve mood.

Just don’t rule out anaerobic, or resistance, exercise. Recent research shows that combining the two can significantly reduce the risk of cardiac events. One reason? Anaerobic exercise changes the composition and activity of muscle fibers, increasing the uptake of glucose into muscles and making muscle fibers more insulin sensitive (so they need less insulin to process glucose effectively).

Move Large Muscles

For cardiovascular benefits, start off using your large muscle groups: • front of your legs, or quadriceps • back of your legs, or hamstrings • gluteals, or buttocks. If you’re out of shape or have a health problem, check with your practitioner first. Begin with a 10-minute aerobic workout and gradually increase your exercise time.

Bicycling, jogging, running, stair climbing, swimming, walking, and water aerobics provide rhythmic, repetitive workouts that increase your heart rate and strengthen large muscle groups. “My favorite is walking, although I love tango dancing as well,” says Judith Sherman-Wolin, an American College of Sports Medicine (ACSM) fitness instructor. You can walk anytime, anywhere. It’s inexpensive (no membership fee, only sturdy, comfortable shoes), and best of all, walking burns, on average, 125 calories every half hour.

Strengthen All Your Muscles

An ideal exercise plan includes warming up (along with stretching), 20 to 30 minutes of aerobics, followed by 30 to 40 minutes of resistance training (calisthenics, Pilates, weight training), finishing up with stretching and cool down. In addition to toning muscles and improving body composition, anaerobic exercise can help increase bone density. That’s important when you realize that as many as 10 million Americans over 50 have osteoporosis (loss of bone density) and another 34 million are at risk for thinning bones.

As you begin resistance training—whether using free weights or machines—select a weight that you can sustain for 8 to 12 repetitions, or reps. Aim to perform these reps two to three days a week.

Healthy adults may increase the weight they lift by about 5 to 10 percent once they can perform a set by one or two reps above their prescribed or usual number. If you’re using 20-pound weights and can successfully complete 11 or 12 reps without feeling any strain, you’re ready to increase the weight. Next time try a 25-pound dumbbell.

Exercise only until you feel stress on your joints, however. Stop whenever your muscles begin to quiver or you feel pain. “Heavy exercise for more than 40 minutes at a time or exercise that burns more than 2,000 calories a week” can increase oxidative stress and raise cortisol levels, warns Vincent Giampapa, MD, basically canceling out the antiaging benefits.

Recent exercise research from the American College of Sports Medicine also suggests changing your workout routine from day to day. Varying your workout helps prevent muscle strain as well as boredom.

Aerobic versus Anaerobic Exercise

Intense weight training has been found to stiffen carotid arteries. But when performed simultaneously with aerobic workouts, moderate anaerobic training does not appear to harden arteries in healthy young men. Middle-aged and older adults might try rowing because it combines both endurance and strength training—while supporting elasticity in the central arteries.