“Walkers become too efficient from covering the same ground, at the same speed, day after day,” says Michelle Adams, spa and wellness director at the Woodstock Inn & Resort in Vermont. The result: the dreaded plateau.  The fix: “Trick your body past its plateau by walking at a harder intensity for short bursts,” says Adams, who designed this 1-month plan of attack. It wakes up your walks with interval training, hill climbing, and strengthening moves designed to crank up your calorie burn and—finally—help you shed stubborn pounds. Once you’ve reached your goal, you can resume your regular walking workout or continue with one of the plans that follow. (Burn calories and build muscle—all while boosting your mood—with our 21-Day Walk a Little, Lose a Lot Challenge!) Remember to do a 3- to 5-minute warm-up and cool-down before and after each walk, and don’t skip the rest days (two or three per week). Week 1: Build Your Base Too Easy Levels 1 to 3: Barely moving Sleepwalking Zone Levels 4 and 5: Strolling Rut-Busting Zone Level 6: Walking to work; Level 7: Rushing to work; Level 8: Late for work and out of breath Rarely Push Yourself This Hard Level 9: Racing to catch the bus (not doable for more than 90 seconds); Level 10: Racing to catch the bus you left your purse on (after 30 seconds, you’re toast) Monday: Grab a stopwatch and time yourself while you walk as fast as you comfortably can for 1 mile on relatively flat ground. (You can measure a route beforehand using your car odometer.) This is your target to beat. Walk a second mile at a leisurely level 4 pace. Tuesday: Walk for 10 minutes at intensity level 5. Walk an additional 5 minutes at level 6, and 5 more minutes at level 5. Total time: 20 minutes Wednesday: Rest day Thursday: Walk for 10 minutes at level 6. Now stop for a forward-lunge workout to firm up your thighs and butt. (Step your left foot 2 to 3 feet in front of your right. Keeping your left knee directly over your ankle, bend your left knee and lower your right knee toward the ground. Then press back up. Do 10 of these lunges, then switch legs.) Continue walking for 10 minutes at level 5. Total time: 23 minutes (Check out your body on walking.) Friday: Rest day Weekend: Walk for 30 minutes at level 6 on Saturday or Sunday. “Congratulations!” says Adams. “Your aerobic capacity should already feel stronger, and by adding lunges you’re strengthening your walking muscles, too.” Total time: 30 minutes MORE: Walk Off 5 Times More Belly Fat Week 2: Pick Up Steam Monday: Spend 1 minute speekwalking (level 8), moving as fast as you can. Recover for 2 minutes while walking at a moderate pace (level 5 or 6). Alternate between speedwalking for 1 minute and recovery walking for 2 minutes, 10 times. Total time: 30 minutes (See the incredible results you get from walking 30 minutes a day.) Tuesday: Walk for 10 minutes at level 6. Up the intensity to level 7 for 10 minutes, and finish with another 10 minutes at level 6. Total time: 30 minutes Wednesday: Walk for 15 minutes at level 6. Go for an additional 15 minutes at level 7. Total time: 30 minutes Thursday: Walk for 10 minutes at level 7, and another 10 minutes at level 8. Finish with 10 more minutes at level 7. You’ll burn up to 20% more calories this way than you would by staying at level 7 for the whole time, Adams says. Total time: 30 minutes Friday: Rest day  Time yourself as you walk as fast as you comfortably can for 1 mile, to see whether you’ve improved from Week 1. “If you haven’t gotten faster, push yourself a little harder for the next 2 weeks,” says Adams. Remember to take a second rest day. Weekend:  Week 3: Tackle Some Hills Walk uphill for 15 minutes as fast as you can. (No hills in your neighborhood? Use a treadmill on incline setting 7.) At the top of the hill, stop and do 15 forward lunges, then switch legs. Walk for another 15 minutes on flat ground at level 6. Total time: 35 minutes Monday: Tuesday: Find the steepest hill around (or use a treadmill on incline setting 9) and walk up it for 10 minutes as fast as you can. “If you’re running out of steam, visualize yourself standing at the top of the hill,” suggests Adams. “That sort of positive mental picture will get you to the top.” Return to flat ground and walk for 10 minutes at level 7. Find some smaller hills (treadmill incline setting 5) and walk for 10 more minutes as fast as you can. Finish with another 10 minutes on flat ground at level 7. Total time: 40 minutes Wednesday: Pick your own route, varying between hills and flats for 40 minutes. Remember to walk the hills as fast as you can and the flats at level 7. (Or use a treadmill and vary the incline every few minutes.) Total time: 40 minutes MORE: 3 Treadmill Workouts That Beat Boredom And Blast Calories Thursday: Walk uphill for 10 minutes (or use a treadmill on incline setting 7). Stop and do 2 minutes of backward lunges. (Start with feet together. Take a big step backward with your right foot and lower into a lunge. Press back up to the start position and repeat, alternating legs.) Walk for another 15 minutes at level 7 and then do 2 minutes of walking lunges. (Step forward, drop into a lunge, and then rise, bringing your back foot forward to meet your front foot. Continue walking forward, alternating legs as you do lunges.) Finish with speedwalking at level 8 for 10 minutes. Total time: 39 minutes Rest day Friday:  Weekend: You should feel in great shape by now. Walk 1 mile and see how much your time has improved. Savor another day off. MORE: Your 10 Biggest Walking Pains Solved Week 4: Mix It Up Monday: Walk at level 8 for 30 minutes. Walk up some small hills for 10 minutes (or use a treadmill on incline setting 5). Finish by doing 10 forward lunges with each leg. Total time: 43 minutes Tuesday: Rest day  Wednesday: Walk at level 8 for 45 minutes. Finish with 20 squats. (Stand with your feet hip-width apart, arms at sides. Bend your knees and hips, sitting back until your thighs are almost parallel to the ground. Let your arms come forward as you sit back. Then stand back up.) Total time: 48 minutes Thursday: Walk uphill as fast as you can for 10 minutes. Speedwalk (level 8 or 9) on flat ground for 1 minute, then recover by walking at level 5 for 2 minutes. Alternate between speedwalking for 1 minute and recovery walking for 2 minutes, 10 times for a total of 30 minutes. Total time: 40 minutes  Friday: Rest day Weekend: It’s race day! Walk for 1 hour as fast as you can and record your time. Make a note on your calendar so you can race against your time once a month.