One Hour to a Healthier You

Got 10, 20, 30 minutes? See how much your well-being improves each time you exercise.

5 minutes
Boost your brain health. Among 1,740 adults age 65 and older, those who exercised for 15 minutes at least three times a week reduced their dementia risk by about one-third, says a 2006 study in the Annals of Internal Medicine.

Plus: 5-Minute Workouts

10 minutes
Biking for this amount of time daily can rev up your energy and brighten your mood, shows a 2001 study from Northern Arizona University. If you add a 10-minute workout to your day, you'll pump up your cardiovascular fitness by 4.2 percent, according to a 2007 study in the Journal of the American Medical Association.

20 minutes
Spice up your sex life. Hit the treadmill for 20 minutes and you may release a substance associated with increased sexual arousal, reveals a University of Texas at Austin report.

30 minutes
A half hour can do a great deal for your health. In a University of South Carolina study, those who maintained regular moderate exercise -- such as 30 minutes of brisk walking five times a week -- had a 30 percent lower stroke risk than their couch-potato counterparts.

A similar exercise dose provided protection against breast cancer, lowering risk by about 18 percent, reports a Fred Hutchinson Cancer Research Center study. A daily 30-minute walk may also thwart aging-related damage linked to Alzheimer's and Parkinson's disease, a University of Florida study indicates.

Plus: 20 Power Foods You Should Be Eating

40 minutes
Raise your HDLs ("good" cholesterol) and decrease your risk of cardiovascular disease with 40-minute workouts.

A meta-analysis published in a 2007 issue of the Archives of Internal Medicine showed that women who average 3.7 of these workouts each week can potentially reduce their risk of cardiovascular disease by 7.6 percent.

Moving for 40 minutes or more five times a week can also ease stress in pre- and postmenopausal women, according to Temple University research released this year.

45 minutes
Stay sniffle-free. Among the volunteers for a study published in the American Journal of Medicine, those who stuck to a 45-minute moderate intensity workout five days a week were more than three times less likely to develop a cold.

50 minutes
Trim excess belly fat by going for lengthier sweat sessions. In a 2006 study from the International Journal of Obesity, middle-aged women who exercised on a treadmill for 50 minutes three times a week flaunted smaller waistlines (on average, 4 inches slimmer) and dropped up to 23 pounds after 20 weeks.

Those workouts also shrunk their abdominal fat cells by about 18 percent, which could help prevent heart disease and diabetes, the study's authors report.

60 minutes
Bumping up your exercise to a full hour -- and including a few strength-training moves -- may keep your bones strong as you age, shows a study published in Osteoporosis International.

When 320 postmenopausal women took on an hour-long exercise routine that paired aerobic activity with weight lifting, they improved their bone mineral density by about 1 to 2 percent in key sites such as the spine and hips.

Plus:
The Best Snacks to Take to Work
Junk-Food Recipe Makeovers
The No-Sweat Workout
How to Curb Bad Snacking