High-knee running is a vigorous cardio workout. It raises your heart rate while strengthening your lower body.
Butt kicks are a cardio workout, just like high-knee running. You can quickly burn calories within 30 minutes by doing butt kicks at a high intensity.
The mountain climber is a cardio exercise that doubles as a full-body workout. Since you need to use your entire body, you’ll burn a lot of calories in a short period of time.
Swimming is a low-impact workout that burns energy while improving muscle strength, blood flow, and lung and heart capacity.
If you have access to a stationary bike, try intervals of high-intensity cycling. As a vigorous cardio workout, stationary bicycling can burn a significant number of calories in 30 minutes.
Generally, running is the best calorie-burning exercise.