9. Mountain Climbers
Mountain climbers are a great way to work on your upper body and core strength while adding cardio through the lower body. Start by stepping one knee in toward your chest at a time, then as you build up strength, you can run them in at a greater pace.
Start in plank position, shoulders directly over your hands and propped up on your toes. With your core engaged, bring your right knee forward under your chest, lifting your foot off the ground. Return your foot to the starting position and switch legs, bringing the left knee forward. Keep switching legs and begin to pick up the pace until it feels a little like running in place in a plank position. Continue running in your plank for 25-50 reps.Image Source: POPSUGAR Photography
