High intensity interval training (HIIT) is one of the best methods of exercise out there. You may know that HIIT is effective, but you might not know why. This month we will be exploring why HIIT training is superior to steady state cardio.
Many traditional exercise training programs focus on the use of steady state aerobic activity (long distance running) for the purpose of improving the efficiency of their energy sources so people can go further for longer. This makes sense because the longer the duration of an activity, the greater the amount of energy used at any time. However, research indicates that cardiovascular adaptations to exercise are dependent on how hard an exercise is and improvements in cardiovascular function via HIIT are superior when compared with more traditional methods.
HIIT has shown greater improvements in VO2max, blood vessel function, blood pressure and cardiac strength. This is important not only for possibly preventing the onset of cardiovascular disease but also in potentially reversing the risk of certain health issues for those suffering from cardiac and overweight disorders
While moderate-intensity steady state cardio (the ‘‘fat-burning zone’’) results in an increased amount of fat burned during a workout, total lipolysis (i.e., fat breakdown) is substantially greater in a HIIT routine. A great example is a study that compared two groups, an endurance-trained group versus a HIIT-trained group. Despite a significantly lower energy cost of the HIIT workouts, at the end of the study participants in the HIIT group experienced a 9 times greater reduction in skinfold thickness.
HIIT increases the body’s potential to use fat as an energy source, more so than steady state cardio. There’s also an increased growth hormone response attributed to HIIT due to the amount of lactic acid we produce. All this plus the fact that HIIT heightens the extent of excess post-exercise oxygen consumption which is the amount of energy and fat you consume after finishing and heading home!
HIIT is a very time-efficient form of training. As few as 6 sessions of HIIT over a 2-week period for a total of about 15 minutes of very intense exercise have been shown to increase muscle performance. 7 HIIT sessions performed over 2 weeks significantly heightened whole body and muscular capacity for fatty acid oxidation (fat burning) during exercise in moderately active individuals. For those who have limited time to workout, this makes HIIT one of the best options.
A recommended HIIT routine for beginners would be an exercise to rest ratio of 1:4, e.g. if you're doing 20 seconds of full on sprinting, have a minute's worth of rest time. If you feel you are more advanced in your ability and fitness then aim for a ratio of 1:1. Finally, if you're feeling REALLY ambitious/crazy/brave (delete as appropriate) try a ratio of 2:1!
As the exercise involved in HIIT is to be done to a high level, it may not be suitable for people with heart conditions. If you're unsure about whether it is right for you, come and see one of the Fitness Team.