A workout so intense that it worries some professionals is set to become the fitness trend of 2014. High intensity training (HIT) used to be the preserve of the most dedicated fitness fanatics but is heading into the mainstream, with one of the UK's largest gym companies capitalising on its popularity.
Fitness First is launching Tabata classes containing a four-minute form of HIT in 50 of its London gyms this month before rolling out the classes nationwide to its 180,000 members in the new year.
The chain claims the Tabata method has been "scientifically proven to be the most effective way to increase both aerobic and anaerobic fitness". Its website cites tests using the system which it says increased VO2 max – the maximum rate of oxygen consumption during exercise – by 13% in six weeks. It says a trial using 30-second "bursts of intensity" with two-minute rest periods was not as effective.
Japanese scientist Professor Izumi Tabata gave his name to the method while working with his country's Olympic speed-skating team. His routine consisted of a combination of 20 seconds of intense exercise, followed by 10 seconds of rest to a rotation lasting four minutes.
Fitness First's website states: "Professor Tabata's latest research shows that if [his regime] is followed correctly, the body will continue to consume more calories for up to 12 hours after the exercise class. These are additional calories to those consumed by the body at rest – so over and above the so-called RMB or Resting Metabolic Rate."
The dangers of HIT training, especially for people who are middle-aged, was highlighted this year when Andrew Marr said that the stroke which almost killed him occurred in the middle of an intense workout on his rowing machine at home.
Fitness First's online promotion does include an advisory note for anyone considering the Tabata class to consult a doctor before beginning the routines, especially if they have existing medical conditions. A spokesman said the 10-minute warm-up followed by a four-minute Tabata rotation "will reap the same benefits as an hour on an exercise bike cycling at moderate rate".
Cardiologist and fitness enthusiast Dr Aseem Malhotra questioned if HIT is the best form of exercise. "Although I don't object in principle to high intensity training, there is no long-term data into its benefits. People exercise for all different reasons," he said. "Some like to push their body to the limits, others do it competitively, but for the majority it's for improving overall health. No one can doubt the multitude of benefits of regular exercise, and as a regular gym enthusiast myself I know of the benefits as much as anyone. But, like anything, too much exercise can be a bad thing, with good data revealing that the greatest cardiovascular benefit for running was up to 20 miles a week at a moderate pace. If you ran more than this at a faster pace the benefits started to get lost."
A study of up to 10,000 former Olympic athletes published in the British Medical Journal revealed that in disciplines with high-intensity activity, such as cycling, boxing and rowing, competitors did not live longer than those at low-intensity sports such as cricket and golf. "In fact, those athletes who engaged in high intensity physical contact sports had a higher mortality than those in the lowest intensity," said Malhotra. "For the majority of the population, improving longevity and general health can be done by brisk walking for 20 minutes three times a week – and doesn't involve spending money joining a gym."
HIT's surge in popularity was highlighted by a recent survey of almost 30,000 people for the American College of Sports Medicine, which showed that, although once the workout of choice for twenty and thirtysomethings, older people and non-fitness enthusiasts planned to attempt the regime in 2014. Last year HIT did not appear in the top 20 of the ACSM's annual list predicting fitness trends, but this year it is number one.Professor Walt Thompson from the University of Georgia and lead author of the ACSM report said: "We've never seen something introduced to the market and catch on so fast."
