The optimal workout includes cardio, strength training, and flexibility exercises. But you don't have to start all at once -- instead, the Whole Body Action Plan lets you build up your exercise routine in small steps over four weeks.

Week 1
During Week 1, devote half an hour a day to gentle exercise -- yoga, stretching, or leisurely walking -- to rev up your circulation. You'll also use this week to assess your fitness so you can chart your improvement at the end of the month. 

Week 2
If you're a fitness beginner, use Week 2 to size up your schedule and pinpoint pockets of time you'll be able to devote to working out. Aim for 30 minutes of walking each day this week, even if it means squeezing in three 10-minute workouts: in the morning, on your lunch break, and at the end of the workday. 

If you're more advanced, amp up your workout during Week 2. Choose from one of the cardio options below, then incorporate intervals of intense activity followed by periods of lighter movement. Try alternating three-minute bursts of walking and jogging, for instance, or switching between three-minute intervals of tough pedaling and leisurely cycling on your bike. 

Cardio
(Calorie burn is based on a 140-pound person exercising for 30 minutes)

Walking: 127 calories

Jogging: 223 calories

Cycling: 159 calories

Swimming: 191 calories

Hiking: 191 calories

Climbing stairs: 191 calories

Rowing: 223 calories

Step aerobics: 191 calories

Dancing: 175 calories

Jumping rope: 255 calories

Elliptical trainer: 175 calories

Snowshoeing: 235 calories

Cross-country skiing: 255 calories

In-line skating: 223 calories

To estimate your calorie burn during other physical activities, use our interactive calculator.