What separates the two approaches
HIIT (high-intensity interval training) alternates short bursts of intense effort with recovery periods; steady-state cardio maintains a consistent, moderate effort level for a sustained duration — genuinely different physiological demands.
Where HIIT has a clear advantage
Time efficiency is HIIT's biggest strength — a 20-minute HIIT session can provide a cardiovascular and calorie-burning stimulus comparable to a considerably longer steady-state session, useful for time-constrained schedules.
Where steady-state has a clear advantage
Lower joint stress, easier recovery between sessions, and a more sustainable, less mentally demanding experience for many people — steady-state can be done more frequently without accumulating the same fatigue as regular HIIT.
A reasonable combined approach
Most people benefit from including both — one or two HIIT sessions for efficiency and cardiovascular challenge, alongside a couple of steady-state sessions for lower-impact, easier-to-sustain activity like walking.