The 28-Day HIIT Challenge – Day 15

For all levels, repeat the set four times. Rest for one minute after each set. Sprint Plank Jumping Jack Plank Rotation Squat Burpee Push-Up Seal Jack Plank Punch Squat Jump Alternating Leg Lift Burpee 1-2 Push Star In-and-Out Abs Squat Pedal

The 28-Day HIIT Challenge – Day 14

High Knees Grasshopper Burpee Spiderman Star Ball Press Jump Lunge Reach Side Suicides Squat Pedal Ski Jump Sphinx Power Knee Squat Jump 1-2 Push

The 28-Day HIIT Challenge – Day 13

Rest for one minute after each round. Sprint Mountain Climber Cross Jack Crab Touch Side Suicides Tiger Push Up Skater Jump Russian Twist

The 28-Day HIIT Challenge – Day 12

Do each set three times. Rest for 30 seconds after each set. Squat Rotated Donkey Kick Lateral Sweep Reverse Lunge Rotated Donkey Kick Lateral Sweep Star Squat Pedal Grasshopper

The 28-Day HIIT Challenge – Day 11

Put your cardio endurance to the test with this routine that goes from high-energy cardio to explosive strength exercises. Remember: Train insane or remain the same! No rest between rounds. Sprint Squat Seal Jack Reverse Lunge Push Up Jump Lunge Cross Jack Squat Jump

The 28-Day HIIT Challenge – Day 8

Rest for two minutes after each round. Sprint Cross Jack The Mummy Mogul Jump Squat Pedal Spiderman Ball Press V-Up

The 28-Day HIIT Challenge – Day 7

Perform each set three times before moving to the next. Rest for 30 seconds between sets. Sprint Cross Jack Seal Jack Mountain Climber Squat Reverse Lunge Squat Hold Lateral Lunge Plank T-Stand The Mummy High Knees Push-Up Pike Bicycle Crunch

The 28-Day HIIT Challenge – Day 6

Each set in this workout is engineered to work as many muscle groups as possible, super-charging your metabolism. Remember form is especially important – quality trumps quantity! Sprint Cross-Country Seal X-Jack Mountain Climber Squat Reverse lunge Squat Jump Jump Lunge Power Knee Burpee Tiger Push-Up