Check it out on Amazon
"High-Intensity Interval Training (HIIT) is the fastest way to drive your fitness to new heights.
This science-backed style of training features short, intense bursts of exercise followed by periods of recovery – allowing you to keep reaching your maximum training zone again and again, shocking your body and driving transformative change.
A true fitness game-changer, HIIT promotes fat burn, improves endurance and increases speed. Science shows it delivers phenomenal results remarkably fast."