This HIIT workout will give you a good amount of high knees to get your heart rate up there then allow you 20 seconds of crunches to bring it down slightly before ramping it back up with more high knees.

This workout will have roughly a 2:1 work/rest ratio.

PERFORM PER ROUND:

• 40 sec – High Knees
• 20 sec – Crunches
• 40 sec – High Knees
• 20 sec – Crunches

Rest 1 minute between rounds.

NUMBER OF ROUNDS:

• Beginner – 6
• Intermediate – 8
• Advanced – 10

This HIIT workout is easily timed with your Gymboss Interval Timer.