Welcome to day 7 of our challenge – things are about to get a whole lot tougher! We are increasing our timings to 50 seconds exercise/10 seconds rest. Starting with 3 rounds of squat jumps, mountain climbers, switch lunges and plank – 12 minutes in total. This type of high intensity training works both your aerobic and anaerobic systems boosting your metabolism, not just for the duration of the workout, but for up to 24 hours afterwards so push as hard as you can. Ready, Set, Go!