With Christmas less than a month away, many people assume it is too late or they are too busy to even contemplate starting (or even maintaining) a fitness program. However, with HIIT training you can squeeze in a significant amount of training to gain great results in a relatively short period of time. What more could you want this time of year?
Those who aren’t familiar with fitness acronyms may well be thinking the idea of a training session named HIIT could be somewhat dangerous or daunting, relax however, HIIT refers to High Intensity Interval Training and can be utilised by individuals of all fitness levels.
HIIT sessions have become a popular style of exercising in recent years due to the physiological impact it has on the body, the short duration in time and the versatility of the session. The key physiological effect of HIIT style training is the use of both the anaerobic and aerobic energy systems. By utilising the anaerobic energy system and reaching levels of 85-95% VO2 Max you increase growth hormone, testosterone, endorphins, adrenaline, noradrenaline, cortisol and aldosterone, which all have a positive effect on body composition and muscle anabolism. It is the higher levels of VO2 Max reached throughout the workout that creates a deficit in oxygen, resulting in what is referred to as Excess Post-exercise Oxygen Consumption (EPOC). The body has to replenish energy stores, repair tissue and balance hormones, resulting in elevated metabolism for a number of hours after a workout, leading to continual energy utilisation and thus the reduction in fat stores. This oxygen demand can be elevated for up to 6-48 hours post workout depending on the intensity of the intervals throughout the session and other physiological factors.
So, since HIIT sessions are so effective, how do you do a HIIT session?
Luckily it is very easy and often you need minimal or no equipment. As the name implies, HIIT is intervals of high intensity, where you exercise at a higher level (85-95% VO2 Max) and then recover with lower intensity moves (roughly 60% VO2 Max). This can be implemented into walking, running, riding a bike, swimming and most cardio activities (you can also add in strengthening exercises; however we will leave that for another article). The intervals and rest can vary on your fitness level and those with lower levels of fitness may need longer recovery. There are various standard types of training protocols such as Tabata which is 20 seconds low intensity followed by 10sec high intensity for eight rounds, however the intervals can be varied based on your fitness and capabilities. According to Mike Boyle it is a good idea to have a 3:1 time ratio of low intensity to high intensity exercise for beginners (for example you may do 1½ minutes low intensity followed by 30 seconds high intensity), however, for those accustomed to exercise it is more beneficial to use heart rate targets to maximise the effect of the session.
The other key bonus of HIIT training is the recommendation is to only engage in this style of training for up to 20 min, with a maximum of 2-3 times per week. So, no long drawn out sessions here, they are quick, intense and effective.
Overall the benefits of HIIT on your health include losing body fat due to the EPOC effect, strengthening of the cardiovascular system, improved fat and carbohydrate oxidisation in skeletal muscles and utilisation of fast twitch muscle fibres. This all leads to decrease overall fat and improved fitness, just in time to enjoy your Christmas dinner.