Popsugar Health & Fitness Full-Body Exercises Indoor Cardio Exercises When It's Raining or Too Hot to Run Outside, I Do These 23 Indoor Cardio Exercises 22 June 2020 by Jenny Sugar View On One Page Photo 2 of 23 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 2 High Knees Run in place while lifting your knees high to the level of your waist. Engage your abs as the knee comes up. Pump your arms to warm up your upper body. Previous Next Start Slideshow Full-Body ExercisesCardioWorkouts