Popsugar Health & Fitness Trainer Tips 45-Minute Full-Body Dumbbell HIIT Workout Build Muscle and Boost Your Heart Rate With This 45-Minute Dumbbell HIIT Workout 11 December 2020 by Maggie Ryan View On One Page Photo 2 of 4 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 2 Warmup Exercise 3: Jumping Jack Start standing with your feet hips-width apart and your arms at your sides. Jump your legs out as you simultaneously swing your hands out to the sides and overhead. Keep your core pulled in toward your spine and land softly as you jump. Jump back to the starting position. Continue for 30 seconds. Previous Next Start Slideshow Trainer TipsDumbbell Workouts45-minute WorkoutsIntermediate WorkoutsFull-Body WorkoutsStrength TrainingWorkouts