Your heart is the single most important muscle in your body, but keeping it in (36) doesn’t require a fancy gym membership or hours of tiring workouts. Squeezing a few brisk walks into your week is all it takes—and because heart disease is the (37) cause of death among women in America, you should get moving now. If you’re over 40, a walking program can reduce you (38) of heart disease by up to 40 percent, as well as (39) your blood pressure, make your heart pump blood more (40) , and improve your circulation. Studies show that regular aerobic exercise, like walking, also reduces stress and (41) fat, says cardiologist Nieca Goldberg, medical director of New York University’s Women’s Heart Program. Our plan is based on the latest (42) from the American Heart Association and the American College of Sports Medicine, which suggest two different walking (43) , depending on your fitness level, to help keep you healthy: walking moderately for 30 minutes, five days a week, or striding at a more (44) pace for 20 minutes, three days a week. First, take a fitness test, then pick the routine that’s right for you, and don’t forget to (45) with your doctor before starting this regimen or any new exercise program. A. lower I. confidentially B. recommendations J. burns C. final K. shape D. leading L. argue E. risk M. check F. normal N. effectively G. strategies O. increase H. vigorous