Photo gallery: 4 simple high-intensity interval training exercises Ready to start a new exercise regime? Find out how you can burn fat and get fit in just four minutes with these high-intensity interval training (HIIT) exercises. By Pamela Mazzuca Prebeg, Personal Trainer, Athletic Therapist Photography by Mark Hong/TC Media Slide: 1 of 7 auto-play pause next first speed High-intensity interval training exercises No time? No equipment? No problem! Here's a super short interval-based workout that you can do in the comfort of your own home. The high-intensity interval training (HIIT) workout involves circuits of 20 seconds of intense exercise followed by 10 seconds of rest, allowing you to improve your overall fitness level, glucose metabolism and fat-burning efficiency. It is a great way to maximize your workout when you're short on time, and it will leave you sweaty, refocused and destressed. Estimated calorie burn: For an average 140 lb woman, each workout will torch 34 calories. What you'll need: Timer or stopwatch (or stopwatch app) High-intensity interval training workout After warming up for five minutes by walking, jogging, climbing stairs or doing jumping jacks, perform the following four moves (shown in the following slides), each in a one-minute circuit: Do Squat Jumps for 20 seconds, then rest for 10 seconds. Repeat again for 20 seconds, then rest again for 10 seconds. Then, move on to Pushups With Knee to Elbow, Plank-to-Pike Jumps and Get Ups. Use this workout in lieu of your regular fitness regimen when you're in a crunch for time. When you have more time, you can repeat the workout two or three times.