Let me start by saying this: if you’ve suddenly decided you want to start exercising but it’s been a long time since you’ve actually elevated your heart rate (other than running to catch a train or chase your child who’s running towards the road), I would most definitely recommend that you start by building a base of aerobic capacity. Anyone performing HIIT sessions will need an adequate level of fitness to begin with.
The reason why HIIT is so popular and guarantees to provide “more bang for your buck” is that, if performed properly, HIIT will produce EPOC (Excess Post-Exercise Oxygen Consumption). EPOC is the result of the body expending energy to recover from disruptions to homeostasis (the natural balance maintained by the body). What that actually means is, you will burn more calories at rest. For example, if you go for a jog you are burning more calories during the jog but a short time after you finish your metabolism returns to normal. If your training is hard enough to produce EPOC the oxygen debt is increased so the body needs to burn more calories to bring the body back to its normal resting state. This can last up to 38 hours post exercise.
Not only does HIIT burn unwanted body fat, it also promotes muscle growth as you are intensely stimulating those muscles only for a short period of time and then allowing time for recovery. This is very favourable for hypertrophy (muscle growth) compared to excessive aerobic activity which can decrease testosterone, increase cortisol (stress hormone) and not only stop hypertrophy but increase catabolism (muscle breakdown). In other words, the reason it supports muscle growth is unlike long steady state cardio, it will not burn your hard earned muscles. Take a look at the different physiques of marathon runners in comparison to sprinters to see the proof.
Guidelines! If your aim is fat loss the session should be short and intense, taking no longer than 30mins – including the warm up and rest intervals (if you are an athlete whose working on certainenergy systems, it would be completely different). If you are able to perform interval training for over 30mins you are not actually doing “high intensity” intervals! HIIT sessions are BALLS TO THE WALLS!! I’m talking flat out MAX effort!! Not just a rushed jog.
There are so many different ways to perform HIIT Sessions. Sprint intervals are a great. Also Tabata workouts (20s work/10s rest over 4 mins) are fantastic because they are so short in duration but can be done using almost any exercise (air squats, burpees, push ups, lunges etc) with little to no equipment needed. You can do barbell complexes, strongman intervals, the list is almost endless. The point is you go HARD! Then you have an adequate rest period before you go again. Honestly once you finish the session you should be pouring with sweat, out of breath and most likely have jelly legs or be laying on the floor wondering what just happened!? The most challenging part is being able to push yourself to this limit. If you have a trainer then great, they will push you. But training alone you have good and bad days so one day you might go all out then the next you slack off a bit. Having a training buddy is a good way to motivate you as you can get a little competitive and help to push one another.
HIIT should also be scheduled into your program only once or possibly twice a week. It is not something that should be included in your daily routine. The central nervous system (CNS) is primarily affected by HIIT and takes a MINIMUM of 48 hours to recover. If you are over using HIIT sessions it can lead to CNS fatigue, metabolic stress, mechanical tension and muscle damage. Needless to say that destroys all of the benefits.
Stay tuned for my next blog where I will go into more detail about overtraining.
Until then, stay strong!!
PS: I’d love you to follow my Facebook page by clicking here x