The original HIIT research papers studied the benefits of HIIT, but only when the participants were achieving Zone 5 (90-95 % of Max HR)
Are there exercises that lends well with the HIIT 20 seconds HIGH, 10 seconds LOW outside of Cycling and Sprinting?
Popular Google links on HIIT webpages show a bunch of easy workouts that seem very unlikely to hit Zone 5 in 20 seconds.
Is Zone 5 hard to achieve without Sprinting, Swimming or Cycling, or are there other workouts that will work?