The 28-Day HIIT Challenge – Day 28

Do each set three times. Rest for 30 seconds after each set. Total time: 45m Warm Up Work Out

The 28-Day HIIT Challenge – Day 27

Rest for one minute after each round. Squat Sprint Jump Lunge Tiger Push-Up Seal Jump Burpee X-Jack

The 28-Day HIIT Challenge – Day 23

Sprint Squat Cross-Country Seal Mountain Climber X-Jack Push-Up Jack Jump Lunge Grasshopper Tiger Push-Up Burpee

The 28-Day HIIT Challenge – Day 22

Perform each set three times before doing the next. Rest for 30 seconds between sets. Sprint X-Jack Seal Jack Mountain Climber Squat Reverse Lunge Squat Jump Jump Lunge Plank Punch Speed Skater Mogul Jump Star High Knees 1-2 Push Pike Double Cross

The 28-Day HIIT Challenge – Day 19

Sprint Cross-Country Seal Power Knee Mountain Climber X-Jack The Mummy Reach Burpee Squat High Knee Jump Lunge

The 28-Day HIIT Challenge – Day 18

Yelling, “I’m a star!” as loudly as possible is optional during this routine, but highly recommended! That brief moment of levity may make you forget how much your legs and legs are burning during this blockbuster workout. X-Jack Jump Lunge Star Cross Push

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