When life interrupts your exercise routine, it can be tough to get back on track: Once that big project at work is finished or a family crisis passes, suddenly you realize it’s been a month since you’ve worked out. “Underdo it at first,” advises Geralyn Coopersmith, M.A., C.S.C.S., a Scarsdale, N.Y.–based personal trainer and author of Fit and Female: The Perfect Fitness and Nutrition Game Plan for Your Unique Body Type (Wiley, 2006). Even if you were in great shape before your hiatus, doing too much too soon can shock your body and lead to another layoff, so follow these tips to ease back into fitness painlessly:

Weeks 1–2 Take a brisk 15-minute walk 3–5 times the first week to get your body used to moving again. Then add 5 minutes to each walking session the following week and another 5 minutes per session the week after. Continue this same pattern until you can walk for 45 minutes to an hour without being exhausted.

Weeks 3-4 Now work in weights twice a week, one exercise for every major muscle group (arms, legs, chest, abs, butt and back). A strength-training routine builds muscle mass and will help you reach your fitness and weight-maintenance goals faster. Use a moderate amount of weight and do 8–12 reps of each move; one move per muscle group should take you about 15 to 20 minutes to complete.

Before and after every workout Always begin with 5 minutes of low-intensity cardio, such as walking, and finish with at least 5 minutes of total-body stretching.

Tags: Aerobic exercise, Body for Life, Exercise, Geralyn Coopersmith, Health, Hospitality/Recreation, Human behavior, Muscle, New York, personal trainer and author, Physical exercise, Recreation, Scarsdale, Walking