I get asked all the time “What’s the best cardio for fat loss?” Science shows that high intensity interval training is the best for fat loss because you burn more energy overall. It also produces a training effect if done at sufficient intensities. The problem with high intensity interval training (HIIT) is that it is hard and most people don’t like doing it.
There is also the principle of diminishing returns at play. If you are athletic and highly training, you will have to work at extremely high intensities to get the same effect whereas someone of lower fitness levels will experience the benefits at lower workloads.
How to do HIIT:
Choose your weapon: Track, Stairs, cardio machine, swimming pool, etc
Choose your intervals: Anywhere from 10 seconds to 2 minutes, depending on your training goals.
Calculate your rest periods: Work-to-rest ratios of 1:2 or 1:3 work well for most people (so 1 interval =1min sprint + 2min jog)
Work it into your schedule once or twice a week to start.
Always do a good 5-10 min dynamic warm-up before you begin each workout.