There are 101 wimpy excuses for not working out—and I know because I’ve used all of them. I’m tired. My favorite show is on TV. I’m hungry. I really should reorganize my kitchen cabinets. But when the weather is really nasty or you’re super-busy, you have a valid reason for forgoing exercise, right? Wrong. Here are 7 simple at-home workouts, many of which can be done in less than 20 minutes. Jumping rope “Jumping rope is amazing for your body,” says Samantha Clayton, personal trainer and co-star of YouTube’s Be Fit In 90. “All you have to do is look at a boxer’s tight, toned body to know it’s a major fat-blaster.” You’re toning your upper and lower body at the same time, while quickly boosting your heart rate. The result: a 160-pound person can torch more than 350 calories in 30 minutes. Check out this jump rope fitness guide for tips and workout ideas. Don’t have the room to swing the rope? Try “ghost jumping,” mimicking the movement without the actual rope. “This is just as effective in keeping your heart rate up,” says Clayton. To keep it interesting, try doing fast intervals with short recoveries in between, challenge your balance by jumping on one leg, double-dutch with the kids, or jump to the beat of your favorite songs. Body-weight workouts No barbells, dumbbells, or resistance bands? No problem. “Your own body is the best piece of equipment you own,” says Clayton. You can get an amazing workout in a small space by mixing and matching basic moves like lunges, squats, mountain climbers, planks, and push-ups. “Squats and lunges tone your legs and butt, and push-ups are great for your chest and arms,” says Clayton. Planks and mountain climbers are fantastic for your abs. Aim to do 3 sets of 10 reps for each move. To boost your calorie burn, keep rests between each move no longer than 20 to 30 seconds. To amp calories even more, add a 1-minute cardio blast—like jumping jacks—between each set. Kettlebells Photo by Barry Murphy/Getty Images “A kettlebell workout can be done in less than half the time of typical workouts and burns twice as many calories,” says Sarah Lurie, author of Kettlebells for Dummies. How many calories are we talking? Up to 20 per minute, according to a 2010 study, or up to 400 calories in a 20-minute session. Here’s why it works so well: “Most kettlebell exercises give you a cardiovascular workout and a full-body strength workout at the same time,” says Lurie. “The basic kettlebell swing works every major muscle group and taxes your cardiovascular system at the same time. Even adding just two kettlebell workouts a week into your routine will transform your body.” Check out our 20-minute kettlebell workout that delivers more fat-fighting and body-toning benefits than doing 30 minutes on the treadmill and 30 minutes of traditional weight lifting. MORE: Get Slim And Sculpted In 20 Minutes Suspension training Loved by personal trainers and hard-bodied fitness types (a former Navy SEAL is credited with their development), these versatile nylon straps hook to any stable anchor—think your bedroom door or a sturdy pole or beam—and allow you to use your own body weight as resistance for more than 100 different exercises. They’re perfect for at-home exercisers because they require minimal space, weigh about 2 pounds, and can be rolled up and stashed in a drawer or closet between sweat sessions. Because suspension strap moves require balance, your abs are constantly engaged, working your body from head-to-toe. To up your calorie burn, move through a suspension circuit quickly, resting only for enough time to adjust strap length between moves. Indoor cycling If you love logging miles on the open road, consider setting up your bike in your living room. “You can put your favorite TV show or movie on the TV and pedal away,” says Andrew Bernstein, gear editor for Bicycling Magazine. “The most common set up is a rear-wheel trainer, which locks onto the bike’s rear hub and elevates the back wheel a few inches off the ground,” says Bernstein. These devices use a resistance unit to simulate riding on a road. You’ll also need a “trainer block” to elevate the front wheel so that your bike is level. Whatever your setup, expect to sweat: A 175-pound person burns between 159 calories to 476 calories in 30 minutes of cycling. “We recommend you get a rubber trainer mat to put underneath you to protect your floors, especially if you’re spinning on carpet,” says Bernstein. Yoga Photo by Hero Images/Getty Images If you have room to unroll a yoga mat, you have enough space for a challenging asana session. To make yoga a great calorie-burner, focus on repeating moves that engage your largest muscle groups and get your heart rate up, says Tamal Dodge, RYT, star of the Element: Hatha & Flow Yoga for Beginners DVD. A few poses to try, in addition to the basic warrior I and II: Crescent lunge, chair pose, and extended side angle. Link them all by flowing through a vinyasa (lower from high plank to low plank, flow forward to upward facing dog, and then press back to downward facing dog). And try our fat-blasting yoga workout for even more burn. Barre work Long used by dancers to sculpt a lean, long body, barre work has become a staple in many exercise studios. The ballet-derived exercises are normally done using a stationary handrail, but you can do them with a chair, kitchen table, or even the back of your couch. Barre work strengthens your deepest ab muscles, pulling in your waist like a corset, while lifting your butt, trimming your thighs, and toning your arms. It also whips into shape your perfect-posture muscles, so you’ll stand straighter. Get started with this three-part video series. Created by Barre3 exercise studio exclusively for Prevention, it’s easy to do at home and you’ll see results fast! MORE: 10 Reasons Your Ab Exercises Aren’t Working