The 10 Best At-Home HIIT Workouts, From 10 to 45 Minutes

Equipment needed: Optional mat.

This 10-minute HIIT ab workout is a little bit of core and cardio. In particular, this session will fire up your obliques, your rectus abdominis (aka your six-pack muscles), and your transverse abdominis (also referred to as the deep core). You'll do each exercise for 30 seconds, and take 10 seconds of rest between each move. There are five ab exercises total, including mountain climbers, side planks, and Russian twists.