Change the time or intensity

Sometimes, you may not be able to get in a full workout. You can still work toward your fitness goals even when life interrupts your best-laid plans, though. Consider:

• Breaking it up. It's great if you can get 30 minutes of continuous activity a day, but you can exercise in shorter bursts, too. Even short walks or breaks for activity count toward your daily exercise goal.

• Kicking it into high gear. If your activity sessions are vigorous, you only need to exercise half the time to meet the minimum weekly recommendations.

  Another option is high-intensity interval training, which involves short bursts of high-intensity activity separated by short periods of lower intensity activity. For example, you can exercise for 30 seconds at your maximum effort and follow it by one to two minutes of low-level recovery activity. Then repeat the cycle for about four to six times.

  High-intensity interval training generally takes between 10 to 20 minutes a session. This type of quickly alternating activity produces many of the same benefits of continuous moderate-intensity exercise in less time.