They probably picked cycling because it's easier to measure and there's less variation. And there's much more literature on it (e.g. Tabata/HIIT protocols). I f

They probably picked cycling because it's easier to measure and there's less variation. And there's much more literature on it (e.g. Tabata/HIIT protocols). I feel squats properly done would be even better as more muscles are involved. With the added benefit of not needing equipment.