Dead Horses and HIIT Junkies
The term HIIT has become synonymous with Gym Shark and Instagram - consequently it has been all over our feeds for the last 8 years. Scroll through any fitness influencer or blogger “home workout” and all they scream about is High Intensity Interval Training. Even newspapers like ‘“The Sun” and “The Daily Mail “ glorify HIIT.
I’m not here to shit on people doing burpees or lunges at home now the gyms are closed but it’s not the only way to get in shape - in fact it’s a limiting method in the long run.
HIIT is a science - science is fact and it yields results. If you don’t follow the science it’s not obliged to help you squeeze into your denims from 2004. HIIT requires work at maximal effort in zones 4 – 5, which is 88% to 95% of maximum heart rate each interval for most people. You can barely talk at this level of exertion.
If you can talk during any HIIT session you got your exercise or intensity selection wrong. Technically any exercises can be done at high intensity, even the bloggers favorites like mountain climbers, shoulder taps, burpees, or some sort of plank variation. However, all these examples are in the frontal plane of motion and work all the muscles you can see (Anterior chain) and none of the ones you probably need to strengthen (Posterior chain).
The low skill level of the above exercises mean you will have to do so many repetitions that you will create a muscle imbalance chasing your goal.
Let’s assume for a second that someone who has been doing HIIT classes isn’t reaching their goal. Could it be that these boutique gyms don’t adhere to any structured programming? Unfortunately that’s the reality - People are paying thousands for a trainer to program while ignoring all the (smart) principles of goal design:
S – specific
M- measurable
A – attainable
R – Relevant
T – time based
You can see straight away that the level of random is high in group exercise classes. More on that later.
The most famous type of HIIT model is called Tabata, invented by Dr Lzumi Tabata. He tested high intensity bursts of 20/10 seconds for 8 rounds against moderate intensity workouts and proved that his protocol can improve both aerobic and anaerobic capacity. It can also increases your EPOC (Post exercise oxygen consumption) - that’s when your muscles need more oxygen than normal and your metabolism rises and burns more calories post workout. Sounds pretty good? Train for 4 minutes and you’re done. Well it’s also about as fun as flogging a dead horse. Also, Dr Lzumi only compared his results against moderate intensity, not against HIIT being done as a saga over multiple sessions per week. So the claims are spurious.
Now, back to the London scene.
Gym owners in London looked at the successful models of Barry’s Bootcamp and Soul Cycle and were envious at the low overhead costs and the waves of cash they could make while charging people £500 a month for group fitness - and so they marketed it and rammed it down our throats.
I call it conveyer belt fitness. Turn the music up loud enough to numb people's senses, lift the incline on the treadmills to make people suffer, and then get some orange skinned steroid beefcake to scream “let’s go team” at them - cue stress response, fight or flight syndrome, and a dump of adrenaline & cortisol all dressed up as endorphins. Sounds bad, but why is that bad you ask?
Well, chances are that you work a stressful job like everybody else. You may have kids and a family. You may commute 2 hours a day. So you are already stressed - HIIT is the maximum stress you can put on your organs in 4 minutes and your adrenal glands feel like giving up because they have dumped its daily allowance of adrenaline to get you through the day.
High stress levels = high cortisol levels.
This messes with your body and its ability to regulate blood sugar levels and deal with inflammation. This in turn can lead to irritability, fatigue, headache, acne, weight gain, and slower recovery. That is basically the opposite of fitness and why you’re paying £500 a month for at the boutique gym.
The HIIT classes are an unsustainable way of treating our bodies unless the recovery is optimal and the training is part of a periodized program. There is a reason athletes train 4 hours a day and sleep for 12. High levels of training require high levels of recovery - and maybe not just sleep but massage, stretching, rolling, cryotherapy, infrared, and more.
So why aren’t these trainers and loyal followers very fit? In order to get people through the doors for extortionate prices they need to sell you an image of what you think a fit healthy dream bod looks like. Did you ever watch Geordie or Jersey shore? All shiny bodies pumped up on substances costing £200 a month. You see my point - we have been conned.
In various races I’ve competed in all over the world it’s the guy with no neck I’m least worried about. Muscles come at a cost and the bigger they are the more oxygen they need to function. When you run a Spartan Race( an event that tests all-round strength and endurance) these shiny glistening bodies don’t stand up to any of the elite wave of athletes on the start line. They lack the aerobic capacity to run short distances like 10km fast enough and their strength is limited to being under a class barbell.
You need - Movement before muscles, Mechanics before load, and to perform the basics like squatting, lunging, pressing, and pulling with no weight before adding it. Disco muscles don’t even come into it.
Measure - what you lifted last session/week/month against today. Work on your weaknesses. Turn yourself into a superior athlete by working SMART. Start training and stop the exercising. In class the randomised repetitions and movements of the instructor will see short term gains that may last a month. Beyond that you WILL plateau using HIIT methodology.
A much better training module would look like this.
Monday - 40 mins intervals at 60-75% bike/ run/ row working between zone 1 recovery and threshold zone 3 most people get aerobically fitter and increase their Vo2 Max with this simple formula
Tuesday - mobility class into accessory workout ( strengthening of weak parts) isolation of muscle with focus on movement quality
Wednesday - REST /active rest
Thursday - Squat/deadlift /clean/snatch large compound movement
Friday - Power session to try to now get the adaptation of yesterday's session. Box jumps sprints box squats cleans . movement performed quickly at lighter % of 5 rep max
Saturday - Row 5km 10km run 20km bike
Sunday - REST /active rest
Even with this slightly generic program you can see that it’s balanced whilst working on strength and endurance. One could argue this plan could take a person to some serious benchmarks like a 40 minute 10km run or a 100kg squat over 6 months provided the base of the trainee is good.
Tell me - have you ever been asked for your goals, exercise history, or had your movement assessed before you did an F45 class?
You have two boxers. Boxer “A” and Boxer “B” that will fight each other in 6 weeks time
“A” is 28 years old and works in the city for long hours but is full of energy and life.
“B” started boxing at the same time as “A” but is 12 years older.
“A” boxes hard for 7 days a week - loves sparring and the hard sessions and gives it his all every time.
“B” boxes 4 times a week at a slower steadier tempo works on his accuracy, head movement, and footwork.
3 weeks into each boxers camp “A” realizes he can’t maintain the level of power in the latter rounds and complains of heavy legs. He decides to reduce his training days to 5.
Meanwhile “B” feels fitter and stronger and decides to take some more rest days before his 4th wk starts.
With 2 weeks until fight night we have two boxers in two very different positions. One is lowering his volume of work because he feels tired (A) and he is deloading before his fight, signaling to his body to resist the high intensity adaptations. “B” is rested and in a position to add load and intensity to his base 2 weeks before the fight. His body is signaling that it can take more intensity and more load.
Fight night arrives.
Boxer “A” comes out swinging wildly and aggressively for the first 3 rounds. “B” rides the initial wave and steadies himself into the contest and now imposes himself on “A”. His superior technique and footwork allowed his older body more time in the ring. “A” only knows one way and that is to keep attacking. It’s a unanimous win for “B” as he is hardly touched. He takes a few weeks rest and schedules another fight in 5 months’ time , thus allowing a new base of conditioning and adaptation to take effect and enough time to work on his weakness as well as seeing his friends and family. “A” goes back to the gym telling friends he felt sick and tired before the fight. He decides Boxing isn’t for him.
Train with specificity whether that be for weight loss, strength, muscle mass, a 10km race, or a boxing bout. You don’t need a fake brand or its fake trainers telling you that HIIT their classes for 45 minutes of your day, 7 days a week will somehow help you to your goals. Resist anything written by a fitness blogger with less than 10,000 hrs in the field of coaching.
If you are still interested in HIIT use it sparingly - Add it once a week to a solid macro periodized program. Beyond that leave it to the park PTs and the pretenders.