HIIT not only provides a physical challenge but improves mental toughness, requiring you to dig deep and push to maximal heart rate to achieve optimal results.

Do each exercise for 20 seconds. Rest one minute after each round.

EXERCISE	WORK	REST
Sprint	0:20	—
Jumping Jack	0:20	—
Squat Thrust	0:20	—
REPEAT 5 ROUNDS	REST 1 MINUTE

trainer tip

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HIIT is all about maximal heart rate, so leave nothing in the tank. At the end of each set, you should be breathing hard and in need of rest. If you find the one-minute rest too long, cut it down to 30 seconds.

The change of elevation in this exercise forces your heart to work harder from battling the force of gravity. Remember: form first, speed second during this challenge. Good Luck!

Do as many squat thrusts as possible during each interval, followed by the specified rest. No rest between rounds.

EXERCISE	WORK	REST
Squat Thrust	0:30	0:15
Squat Thrust	0:30	0:30
Squat Thrust	0:30	0:15
REPEAT 2 ROUNDS	NO REST