Keep on moving, don’t stop! On the coldest days, try this indoor workout.

Getting your blood pumping outdoors — even just a brisk walk around the block — can help keep you strong, healthy, and happy throughout the winter. But when the wind is whipping, the sidewalks are icy, and you feel truly stuck, resist the sofa’s siren song. This indoor cardio circuit from Cleveland Clinic fitness expert Ryan Sidak will jump-start your engine with no home gym required! Do the sequence below two to five times, depending on your fitness level.

High Knees: Standing upright, raise your right knee up toward your chest as high as you can. Return your right foot to the ground and repeat with the left knee. For more intensity, increase the pace so that you are running in place with high knees. Do 20 repetitions.

Mountain Climbers: Secure a chair by pushing it against a wall. Place your palms flat on the seat of the chair and extend your body straight back, in a line from the top of your head to your heels. Begin in a push-up position, hands directly below your shoulders. Now raise one knee, as close to your chest as you can, and return it to the starting positing. Repeat with opposite leg and continue alternating for 20 repetitions. If you’d like, when you’re ready, you can increase the pace for a more intense workout.

Lunges: Standing upright, lift your right foot off the ground and take a big step forward. While shifting your weight to the front right foot, lower the knee of the left leg toward the ground. Be careful that your right knee doesn’t extend beyond your toes. Maintain a good upright posture all the while, and press up through your right heel to the starting position. Perform 6 to 10 lunges, always leading with the right side and then repeating with the left.