Research has shown a wealth of positive results from the ever-increasing number of studies on HIT in terms of performance and physiological measures, including aerobic capacity, carbohydrate metabolism and insulin sensitivity.
According to Professor Martin Gibala from the department of kinesiology at McMaster University in Canada, “HIT simply involves alternating high- and low-intensity efforts.”
Gibala first examined the effects of short blasts of effort on fitness in 2005. His subjects, who were active people but not athletes, cycled against high resistance on an exercise bike for 30-second bursts. Each effort was interspersed with four-minutes of rest or easy pedalling and repeated four to six times, three days a week. Within two weeks, the subjects had doubled the amount of time they could cycle at a pre-set intensity from 26 to 51 minutes.
“If we assess the effect of six weeks of HIT compared with as much as 20 weeks of traditional endurance training, the percentage gain in aerobic capacity is within the exact same range.” said Professor Jamie Timmons, the chair of ageing biology at the University of Birmingham in the United Kingdom.
Research at Heriot-Watt University in Edinburgh found that, after only two weeks of HIT, sedentary men experienced reductions in both glucose and insulin levels.
“HIT training addresses two of the major health benefits of exercise, insulin sensitivity and aerobic capacity, while simultaneously removing the time barrier to exercise,” said Timmons.
With lack of time often cited as a reason for not exercising, it is certainly appealing that you can complete your exercise regime in less time than your post-workout shower.
But Professor Paddy Ekkekakis, from the department of health and human performance at Iowa State University in the United States, said there was no evidence to suggest this meant a greater adherence.
There was also concern that for the totally inactive, HIT training was likely to be too uncomfortable or even dangerous. It was this that prompted Gibala to assess the effects of a modified form of HIT involving 10 one-minute efforts with one-minute recoveries.
However, Gibala said three sessions of 30 minutes a week is a far cry from the allure of three minutes a day and sounds a lot like the type of session many keen exercisers already embark on. For someone who is already active, does HIT present a way to improve your performance?
“For those already doing sprint training and weights as part of their regime, HIT will not add that much,” said Timmons. “But if your training is sub-maximal, then HIT could improve insulin sensitivity and promote muscle-mass gain.”
Darul Ihsan Media Desk