the wildly popular and hyperintense cardio workout has many faces: that guy sprinting full-tilt on the treadmill, the girl whipping ropes into the floor like a child throwing a tantrum.
It also encompasses kettlebell swings, kickboxing classes, burpees — and basically anything else that involves short bursts of brutally intense exercise followed by periods of lighter activity or rest.
It also encompasses kettlebell swings, kickboxing classes, burpees — and basically anything else that involves short bursts of brutally intense exercise followed by periods of lighter activity or rest.
leading movement in cardiovascular exercise for fat loss and
conditioning for more than a decade. Fuelled by claims of
faster fat loss, shorter workouts, and less monotony (along with exclamations such as “It kicked my arse” or “Made me puke”), HIIT has largely supplanted traditional aerobic training — of the just-go-out-and-jog variety — as the preferred conditioning method of gym-goers everywhere. But old-fashioned roadwork, the kind that Muhammad Ali and dozens of other champion athletes utilised, isn’t obsolete. In fact, it may actually be the more important style of cardio exercise for anyone looking to be in better, more well-rounded shape.
In 1996, a study was published that has perhaps done more
to buoy the current HIIT movement than any other. Japanese
researchers, led by Izumi Tabata, published the now-famous
Tabata study, which showed that well-trained young men
improved anaerobic endurance more in six weeks with interval training than a control group did by performing aerobic exercise. The experimental group performed intervals for only four minutes at a blistering intensity — 20 seconds on, 10 seconds off. Because of the remarkably short workout time, the study has been hailed as proof that HIIT is vastly more efficient than aerobic training. However, the findings have since been greatly exaggerated to suit the HIIT agenda, and experts argue that the study simply doesn’t apply to
the regular gym-goer. For one thing, results for the interval group began to level off after the third week. For another, the
interval group performed some aerobic training (30 minutes’
worth) in addition to the intervals, so it wasn’t a pure test of
HIIT. Furthermore, the “moderately trained” experimental
group performed its intervals at a staggering 170% of VO2
max, the maximum amount of oxygen the body can use
during exercise. Considering that 100% of VO2 max is enough to exhaust most people, you get a sense of just how fit these “moderate” subjects were.
Now consider a 2008 study from Medicine & Science in Sports & Exercise, in which eight obese men trained for four weeks at a moderate, constant pace (also known as “steady state”). Data were collected, and the men then performed another four weeks of intense interval training. On both programs, the subjects’ diets were set to avoid weight loss to allow for a pure test of the exercise protocols.
The workout length on both programs was the same, and so was the subjects’ average energy expenditure and body composition (remember, they never cut calories from the diet). Still, the men burnt a lot more fat on the steadystate protocol than with the intervals. In fact, the aerobic training yielded a significant jump of 44% in the amount.
