If you’re looking to lose body fat and work your muscles, this 45-minute workout designed by ACE-certified fitness instructor John Kersbergen is the place to start. It combines cardio with strength training moves, so aside from burning calories, it’ll also help you build muscle, which increases your metabolic rate and helps you burn more calories when you’re not working out. Essentially, this routine will help you effectively, efficiently lose weight without taking up too much time, but take this warning: it’s fast-paced and will leave you dripping with sweat! Before we get into the workout, a few quick reminders. This workout can help you build muscle when done consistently, but you’ll also want to eat a balanced, protein-filled diet and get adequate sleep to reach that goal. The same goes for losing weight; a consistent workout routine is key (including workouts like this one), buy so is eating a nutrient-dense diet and working towards a modest calorie deficit (burning more calories than you consume). It’s important to remember that some factors that you can’t control, such as your genes and hormones, will also impact your weight loss. With all that said, this is a Tabata workout, which is a form of high-intensity interval training (HIIT). It’s a good choice for weight loss, as studies have indicated that HIIT workouts may help diminish belly fat more effectively than steady-state cardio. Each four-minute section of this workout involves eight rounds of 20 seconds of work followed by 10 seconds of rest. What makes this workout so intense is that it’s long: 45 minutes total! You get a one-minute rest every 12 minutes, so soak it up, and remember that if you’re at your limit or just not used to this style of training, it’s OK to take a longer rest or complete your exercises at a slower pace. Drink some water, catch your breath, walk around a little, and then get ready to rev up the intensity once again. Related: Start Our 30-Day Beginner Bodyweight Challenge Today and Get Stronger Every Day! 45-Minute HIIT Workout For Weight Loss Equipment needed: jump rope (if you don’t have one, just pretend!), medium- to heavy-weight dumbbells (five to 20; here are more tips for choosing the right weight), and a clock, timer, or Tabata app to keep track of time. Directions: Start by completing the warmup circuit below as many times as you can in five minutes. Then, start the first block of the workout. Do 20 seconds of the first exercise, then rest for 10 seconds before completing 20 seconds of the second exercise. Rest for 10 seconds, then repeat the two-move circuit for four rounds total. Repeat this format for each block, taking a longer, one-minute rest where indicated. Cool down after the workout with full-body stretches. 0:00-5:00 Warmup Repeat as many times as you can in 5 minutes 10 jumping jacks 10 forward backward lunges (5 per side) 10 plank jacks 5:01-6:00 Rest 6:01-10:00 Cardio Repeat 4x 20 seconds jump rope, 10 seconds rest 20 seconds mountain climbers, 10 seconds rest 10:01-14:00 Legs Repeat 4x 20 seconds air squats, 10 seconds rest 20 seconds goblet squats, 10 seconds rest 14:01-18:00 Arms Repeat 4x 20 seconds triceps push-ups, 10 seconds rest 20 seconds dumbbell thrusters, 10 seconds rest 18:01-19:00 Rest 19:01-23:00 Core Repeat 4x 20 seconds plank with bunny hops, 10 seconds rest 20 seconds v-sits, 10 seconds rest 23:01-27:00 Cardio Repeat 4x 20 seconds jump rope, 10 seconds rest 20 seconds mountain climbers, 10 seconds rest 27:01-31:00 Plyo Repeat 4x 20 seconds burpees, 10 seconds rest 20 seconds split lunge jumps, 10 seconds rest 31:01-32:00 Rest 32:01-36:00 Back Repeat 4x 20 seconds superman lifts, 10 seconds rest 20 seconds plank with row, 10 seconds rest 36:01-40:00 Butt Repeat 4x 20 seconds jump squats, 10 seconds rest 20 seconds deadlifts, 10 seconds rest 40:01-44:00 Cardio Repeat 4x 20 seconds jump rope, 10 seconds rest 20 seconds mountain climbers, 10 seconds rest 44:01-45:00 Rest Keep reading for a description of each move. Related: Transform Your Abs With This 2-Week Crunch Challenge – It Takes Just a Few Minutes a Day!