"We may not like to see sweat on treadmills or public speakers," say Drs. Roizen and Oz, "but we want to see it on YOU." Why? "Because the way to improve heart function is to sweat more than a kid in the principal’s office."

Cardiovascular activity lowers both the top (systolic) and the bottom (diastolic) numbers of your blood pressure. Cardio exercise may also help keep your blood vessels more elastic by forcing them to dilate.

In addition to 30 minutes of daily walking, aim for a minimum of 1 hour a week of sweaty activity -- ideally in three 20-minute sessions -- during which you raise your heart rate to 80% its age-adjusted maximum (220 minus your age) for extended periods of time.

Or try this: After warming up, go for maximum effort for 1 minute, and then slow down for 2 minutes. Then go to 80% of maximum for seven minutes. Then cool down.

Opt for low-impact activities like swimming, cycling, or an elliptical trainer to get your heart rate up without stressing your joints.