Defined as workouts that high intensity exercise followed by equal or slightly longer periods of recovery.HIIT was first lauded for offering improvements in cardiovascular fitness similar to workouts that took twice as long.
There is a Caveat:HIIT demands exercisers workout at 90-100 percent of maximum effort.That means exercisers need to push their body to its physical limit each and every interval.This "lots of pain;lots of gain"approach to exercise isn't meant for everyone.In fact;during the early days of HIIT;research there was a caution that it might not be safe for anyone unaccustomed to intense exercise and it was definitely out of bounds for the obese and those trying to manage chronic disease.
But in the last few years there has been more talk that HIIT shouldn't be limited to helping the fit get fitter.New research suggests the time efficient benefits of HIIT can still be gained by performing intervals that aren't quite as demanding as first proposed.Instead of 30 second intervals executed at an all-out sprint like intensity intervals of one to three minutes at closer to 80 percent of maximum effort followed by up to five minutes of lower intensity exercise are now considered effective HIIT workouts.
We are talking about workouts relative to one's own level of aerobic fitness.For the unfit that would mean repeated bouts of fast walking followed by easy recovery intervals versus the Usain Bolt -like sprints that are more typical associated with HIIT.
What types of benefits are talking about?
Several studies have confirmed that HIIT workout improves cardiovascular fitness as effectively or more effectively than moderate intensity workouts that typically take twice as long and there is little doubt that the health benefits associated with improve fitness reduced risk of heart disease and metabolic disorders are also a byproduct of HIIT.B ut how does it measured against some of the other claims associated with this so called "miracle"workout.Does it get rid of unwanted fat and build muscle?In these two areas the jury's still out a recent meta analysis done by a team of French researchers investigated the effect of HIIT workouts on total abdominal and visceral fat on non athletic subjects.The results showed HIIT to be effective in reducing fat in overweight or obese subjects but not in so called "normal weight" exercisers.It also indicated that HIIT sessions involving running were more effective at reducing abdominal and visceral fat than cycling intervals.Also noteworthy is that higher intensity HIIT sessions were more effective at reducing overall fat stores. While lower intensity workouts were better at decreasing abdominal and visceral fat.
A final word of caution: Even though HIIT workouts are now considered safe for an increasing wider range of Canadians,those with uncontrolled diabetes or hypertension or with a history of cardiac events should stick with more moderate intensity workouts unless cleared by their physician.