Workout trends come and go, and one of these that is getting a lot of attention is High Intensity Training (HIT). The attention, such as that in television shows like Catalyst and Michael Mosely’s ‘The truth about exercise’ (claiming that 6 minutes of exercise per week is all that we need) is largely well deserved, but as with anything, there are always two sides to the story. Let’s start with some definitions and then make sure we end up with a balanced and informed perspective!
HIT (High Intensity Training)
High Intensity Training (HIT) is the umbrella term given to a number of different high intensity training modalities. The measures used to determine the level of intensity are typically Heart Rate, or a Rating of Perceived Exertion (RPE). To qualify as high intensity, Heart Rate needs to be be over 70% of maximum heart rate (if you don’t know what yours is from personally testing it, it can be calculated by substracting your age (in yrs) from 220); and the exercise needs to be considered to be ‘hard’, or around 5-6 on an RPE scale, where 1 is “very, very easy”, and 10 is “maximal”.
HIIT (High Intensity Interval Training)
HIIT involves alternating short periods (Intervals) of work and rest over the duration of a session. The intervals can be programmed in different ways, with their length and actual intensities varying to meet the desired demands. For example, the lengths and intensities of the ‘work’ intervals can range very widely, to address either the anaerobic threshold, or maximal anaerobic power. Similarly, the rest period can be performed as active or passive rest.
HIRT (High Intensity Resistance Training)
A close member of the family, HIRT is based on the well researched varieties of cardiovascular based HIT training, but is performed largely with ‘weights’. So the work intervals may be made up of exercises that you may be more used to seeing in a gym floor, such as squats, lunges, presses, kettlebell swings, etc.
So, why would we bother with these types of training, and how do they compare to more traditional training methods?
Studies consistently show that HIIT improves metabolic health markers and fitness measures. For example Irving et al. (2008, Med Sci Sport Exerc) found that after 16 weeks of exercise, women with Metabolic Syndrome lost twice the amount of weight and fat mass, and four times the amount of fat around the abdomen when compared to those who did the same amount (isocaloric) of low intensity training. These type of studies strongly show that when it comes to energy in, or out, the amount of calories (or kilojoules) themselves are less important than the hormonal response that is created; with suggested mechanisms to explain this difference including improved insulin sensitivity and cortisol levels. More on the hormonal effect on energy in and out on weight management on a blog coming out soon!
High intensity training has been shown to reduce the risk of dying prematurely by up to 17% compared to those who do no HIT (Tanasescu et al, 2002, J Am Med Assoc), and after only one training session a week! Other often cited benefits include: reduce subcutaneous fat; improved insulin sensitivity; total body mass; aerobic fitness; blood pressure and glucose regulation; improved lipid profiles; and greater tolerance to stress! phew, great list!!
In addition, different varieties of HIT may be seen as more attractive exercise options, due to the opportunity to gain greater health benefits in less time. For those who lack motivation it may be a more enticing option than the prospect of continuously exercising for an extended period of time.
Bartlett (et al. 2011) found that the ratings of perceived enjoyment (yes, “enjoyment”) after HIIT were higher when compared to moderate intensity training. Considering that ‘lack of time’ remains the most commonly cited barrier to regular exercise participation, this seems too good to be real, right?! Well, perhaps.
There’s certainly some things that we need to be aware of:
While the physiological effects are evident, the duration of most studies is very short, with very short follow-ups, and largely in unhealthy populations. The long-term effect of has not been well established and if I was to take a guess I would say that eventually there would be a decreased return on investment. A yet to be published (large scale) study looking at physical activity trends in Australia shows that more Australians are performing vigorous physical activity; but less low-moderate physical activity; and the amount of sedentary time continues to increase. It appears that while HIIT is certainly more time efficient, the less time we spend moving the more opportunity we allow for sedentary time. This might help explain the increasing rates of Type II diabetes and Cardiovascular Disease, as it is well accepted that the negative physiological effects of sedentary time can cancel out and even outweigh the physiological benefits of exercise.
In addition, by its very nature, high intensity exercise carries a greater risk of injury, particularly for those new to exercise, so careful and guided progressions are recommended!
To conclude, other than the imbalance that is created between active and sedentary time, by shortening exercise time, I believe there is another significant issue with the way that research on HIT training is communicated to the public. The type of reporting seen in the media only reinforces the mindset that exercise is like some nasty medicine that we need to take, so we are best off pinching our nose and getting it over and done with as fast as possible! Surely the message should rather be one of promoting an active lifestyle, and that HIIT training can be a fantastic adjunct to that? Our body is the machinery that we have to go out and experience the world in and with, and the broader and deeper our physical capabilities, the wider the range of experiences we can potentially have. While High Intensity Training can certainly help us improve some specific health measures, does it help us live our lives more fully?
Written By Max Martin
Sixteen years ago as a work experience student I had my first exposure to a gym. I was looking for something that I was vaguely interested in, and thought exercise was cool so I ended up at my local workout centre. My lasting memory from this time is of men and women doing bench presses and bicep curls in front of mirrors. They watched their chests and arms intently, admiring their shapes. The moves that they performed were mechanical and repetitious, and required little thought. I suppose this simplistic type of routine allowed attention to be directed towards the appearance of one’s body under exertion.
Then, on every wall, were large pictures of male and female icons. It was as if these were to serve as a constant reference as to how we should LOOK. The problem as I saw it was that these people were in pursuit of an aesthetically based ideal that had been determined by somebody else (and their airbrush, perhaps). In reality, what was genetically, functionally, metabolically and specifically ideal for them may have actually looked quite different.
The pursuit of aesthetics through exercise is disappointing. It minimalises the amazing and complex processes that occur within our bodies when we move, and lands us in a realm where ultimate satisfaction is rarely acheived or maintained. Exercise with intent breeds internal intelligence. It challenges and alters the paradigm of exercise, and opens a world of possibilities that lay beneath what we can see in the mirror.
Here’s some scary stats for you:
- 80% of the Australian population has suffered from low back pain at some stage in their life.
- 25% is suffering from it right NOW!! – there’s a good chance that this may be you as you read this. And one in four people that you walk past tomorrow will be suffering from low back pain… wow… maybe we can understand the serious face!
- A recent study by the Chiropractors Association of Australia (CAA) recently found that more than a third of Australian retirees suffer from daily low back pain. that is not how I hope to spend my retirement.
Now here’s the really scary part: 45% of Australians will chose to take a painkiller to deal with their pain (knowing that the painkiller will have no long term effect on the condition) over trying to find a sustainable approach to improving their condition. This can be successfully achieved by finding and improving the cause of the problem.
The study indicated that we can reduce the chance of suffering from frequent back pain by 18% by exercising for atleast 30 minutes a day. Also, reducing stress, and dietary changes can have a significant effects on low back pain. For more on this particular factor, please refer to our previous post on Omega 3s (http://informhealth.wordpress.com/2009/06/15/green-vs-brown-carbs-the-omega-argument/)
Here’s some more good news (depending on your perspective!): a study by Hendrickson (2002) indicates that of those people suffering from frequent low back pain, 98% of cases are due to mechanical and functional issues, and not due to true pathologies (such as arthritis, disc damage, muscle/tendon/ligament tears, etc). This is great news because functional issues are relatively easy to address! these issues would include having some muscles that are not working to their correct level, while others are compensating for this and becoming overly tight.
Such dysfunctions are successfully treated on a daily basis by quality Physiotherapists, chiropractors, exercise physiologists and personal trainers.
So please, don’t just pop a pill to deal with the pain!! there’s simple ways to address the causes of low back pain in most cases, which will make you feel better in a number of different ways, beyond just taking your pain away.
In our last post we left off with a recommendation to increase vegetable intake as a means of reducing total carbohydrate intake, and to also improve the ratio between 0mega-3s and omega-6s. This is very important as this ratio is totally unbalanced by our common western diets, which, among other things will also increase the level of inflammation that we are under.
Chronic inflammation can occur when your body is constantly fighting a disease or condition that is putting undue stress on a particular area. It is relatively common in people suffering from cancer, arthritis, lower back pain, asthma and depression. In extreme cases this inflammation creates a breakdown of muscle tissue with associated weight loss, which is known as cachexia.
While the exact cause of this chronic inflammation is poorly understood, what is known is that specific messenger cells called cytokines are released which act to amplify the inflammation process in the body. Under most circumstances this is a very important process because this pro-inflammatory mechanism is very important in the healing process when the body’s tissues and organs are damaged and also act to help trigger our white blood cells to action when we have a virus or infection.
However, when this process is unable to be “switched off” this amplification process builds on itself and creates a breakdown of muscle tissue and we get associated loss of strength and a decreased quality of life. In this case it is beneficial for us to break the inflammation cycle as under these chronic inflammation conditions it is very hard for us to build muscle.
We also know that the inflammatory cytokines are mediated through messengers called eicosanoids. Depending on the eicosanoids involved there may be a pro-inflammatory or anti-inflammatory response. The pro-inflammatory eicosanoids are the by products of omega-6 fatty acids while omega-3 fatty acids create anti-inflammatory eicosanoids.
These essential fatty acids (our body cannot produce these), are gained from our diet. A general rule is that the brown things that we eat (grains, bread etc) have a high amount of omega-6 (pro-inflammation) while the green things that we eat have high amounts of omega-3 (anti-inflammation). It is not a wonder then that our western diet has moved from approximately a 3:1 ratio of omega-6 to omega-3’s, to approximately a 15+:1 ratio!
How do we break this chronic inflammation cycle?
Obviously for us to break the inflammation cycle we need to alter our ratio of omega-6 to omega-3 in favour of the anti-inflammatory process. Research has shown that by supplementing with fish oil, which has high concentrations of Omega-3 fatty acids in the form of EPA & DHA, we can decrease the amount of inflammation in the body.
However, the dosage required is quite high (approximately 1kg of oily fish per day!) for someone in a cachexic state and the only safe way to get this amount without the risk of mercury poisoning is with a practitioner grade fish oil supplement.
It should be noted that large dosages of fish oil may cause gastrointestinal problems, and there is also a risk of blood thinning at very high dosages (above 6g of fish oil per day).
Other benefits of fish oil
Omega-3 fatty acids have also been shown to be beneficial for other health conditions including: hypertriglyceridemia, hypertension, rheumatoid arthritis, stroke prevention, atherosclerosis, angina, cancer prevention, brain/eye development in infants, Crohn’s disease, Lupus, psoriasis, eczema, asthma, depression and mental illnesses.
For more information on fish oil or the inflammation process talk to one of our Exercise Physiologists.
I know I’m not alone in my concern for the health of Australians and I’m not the first (by any stretch of the imagination) to report on the seriousness of the issue. However, I believe that right now we are facing a ‘critical’ period that requires our prioritized attention. The combination of a number of factors have led to two thirds of respondents to a recent survey stating that they would re-consider gym memberships due to financial pressures.
On the other hand, at a time of global focus on sporting competition, we have as a nation officially become the heavyweight champion of the world! Unfortunately this is not a title we want to have. Figures from a recent study released by the Baker IDI Heart and Diabetes Institute, report that 26 per cent of adult Australians are now obese, one million more than the last calculation in 1999! The findings give Australia a Gold Medal as the world’s fattest nation, ahead of the notoriously super-sized Americans, who have a 25 per cent obesity rate.
Based on these shocking new statistics, Access Economics has recalculated the costs of the burden of obesity on our nation. Their report, released at a government forum in Tasmania in August, shows the full cost to be $58 billion, far exceeding the $21 billion bill estimated in 2006. The direct costs are estimated at $8.3 billion, with a further $49.9 billion attributable to the value of lost wellbeing and premature death.
In the face of such news, can we afford to stand with arms crossed while people ‘reconsider’ the importance and value of their health? Should we as a nation re-evaluate what is most important to us? Should we achieve national pride from winning the greatest number of medals per head of population, as we tend to do, or from having a healthy and vibrant population?
Can we make a difference? I believe so! But as the health and economical environment changes, it is critical that the decisions we make change as well. ‘Fitness’ is unfortunately becoming a discretional item. As budgets tighten, gym memberships and personal training sessions are one of the first things to go. It is imperative that the message we give our community at large is one that extends past ‘just’ fitness and highlights the impact of their daily behaviours, such as their nutrition and physical activity, on health.
Dr Gary Deed, national president of Diabetes Australia, which commissioned the Access Economics report, said that the obesity epidemic was having a “direct and catastrophic influence on increasing the incidence of type-two diabetes. We know that obesity and type-two diabetes can be prevented and we need to make fundamental changes in the way we live to arrest the escalating crisis”. The report estimates that 242,000 Australians have type-two diabetes as a direct result of their obesity, a further 650,000 Australians can blame their cardiovascular disease on their weight, and more than 30,000 have colorectal, breast, uterine or kidney cancer as a result of their physique.
So we now face a critical time to make decisions with far reaching implications. It was not long after our Olympic Athletes had touched Australian soil after their great achievements in Beijing, discussions started about increasing funding to Olympic programs in preparation for the London Games. I am personally involved in the development of athletes, including current medalists at Beijing.
I think this is an issue of motivations and priorities. We have for a long time justified the millions of dollars spent per Olympic Medal won based on what’s known as ‘the trickle-down effect’. This speculates that success on the world stage will flow on and increase sports and physical activity participation at a grass roots level, a theory that unfortunately has not proved to be correct.
Our challenge then, lies in deciding what to do with our tax dollars already tagged for ‘sports’ and ‘health’. Will we continue to pump them into an international ‘pride’ building contest or strategically allocate them to help reduce our rapidly increasing rates of obesity and related diseases?
For further information please contact our iNform Accredited Practitioners by visiting http://www.informhealth.com/