You've probably done a HIIT workout or two in your time. Like running and weight training, it's a seriously popular way of getting a sweat on, with 83,500,000 Google results for the workout alone.
Loved by the likes of world-famous personal trainers Joe Wicks and Kayla Itsines, it's often regarded as one of the easiest simple home workouts you can do (no kit required). All you need is 15 minutes of spare time, a good sports bra, and a bit of motivation.
