High-Intensity Interval Training (HIIT) is something of a buzzword at the moment – and rightly so. Highly popular* and results driven, the American College of Sports Medicine states that the benefits of HIIT include increased aerobic and anaerobic fitness, lowered blood pressure, improved cardiovascular health and insulin profiles, and a reduction in abdominal fat and body weight while maintaining muscle mass. And with new workouts and studios launching with increasing regularity, HIIT appears to be a trend that is still very much on the rise.
However, with many HIIT sessions offering not just a high-intensity but also a high-impact workout, there is a growing need within the industry for alternative, lower-impact options, as a means of providing suitable classes for clients of all fitness levels. It is also important to offer recovery-style classes that can be interspersed with HIIT, to include more variety, reduce injury risk and even add longevity to your career as a personal trainer or instructor, due to the fact your body will be subjected to fewer stress-inducing workouts.
‘If you’ve done a HIIT workout properly then your muscles will be ripped to shreds, so recovery is absolutely crucial,’ advises James Winfield, sports scientist, personal trainer and founder of ReboundUK.
‘You really can have too much of a good thing. If you over train and find you plateau or burn out with your HIIT sessions, this is a sure sign you need to switch it up, find an alternative high-intensity exercise, or intersperse with some other styles of workout.’
University of British Columbia state that ‘high-intensity “sprint training” may be gaining popularity at gyms, but if you are new to this form of exercise, the workout could do more harm than good. A study has found signs of stress in the muscle tissues of their non-athlete, untrained subjects after ultra-intense leg and arm cycling exercises. Perhaps more concerning, researchers reported the untrained subjects had a weakened ability to fight off free radicals, molecules that can alter DNA and harm healthy cells.’
‘Our study raises questions about what the right dose and intensity of exercise for the average person really is,’ said Robert Boushel, the study's senior author and director of the University of British Columbia's School of Kinesiology. ‘We need to be cautious about supporting sprint training in the general population.’
The study was carried out on a dozen male volunteers in Sweden, all of whom were in good health but self-identified as untrained or only moderately active. The men participated in high-intensity training over the course of two weeks that involved repeated 30-second all-out sprints, followed by rest periods.
On the flip side, then, it appears HIIT can place a huge strain on the body, especially for those clients are out of condition to begin with, or those who rarely mix up their HIIT sessions with other activities and workouts.
‘There are a lot of people out there who love HIIT training, and that’s great,’ says Winfield. ‘I just think for deconditioned people,