If its cold or rainy, she heads to the gym and hops on the treadmill. The truth is that both high-intensity interval training and steady-state cardio are effective in. Try these three quick and efficient HIIT workouts designed. calories in a short amount of time so you dont need to spend hours in the gym. Whether you want to see improvements in fitness or weight loss, add. interval training and a group doing steady-paced cardio workouts.