I refined the article I did for Wangle to make an information sheet for the gym, thought I'd repost it here, as I'm much happier with this article, than the original.
Forget what you think you know when it comes to fat loss! Distance running, distance walking, steady state exercise, whatever you want to call it, is a thing of the past. As a personal trainer, I understand that you love to run; it gets you free from the constraints of your daily life, it relaxes you. I get it. But this is one of my biggest headaches.
What’s the problem you ask? Simply put, when you run one kilometre, you’ll subject your joints to roughly 1500 jumping steps at a minimum of 2-4x your body weight (do the math, it’s pretty scary). This is an extraordinary amount of pressure on them. What is the result of this? Specific knee and lower back problems, in fact most of the runners I have seen complain of the same issues: plantar fasciitis lower back pain and patello-femoral problems. Women in particular, can be more affected due to the structure of their hip in relation to their knee (although not, necessarily).
Still, you may be thinking that it’s perhaps the best and only tool you have for fat loss?
Let’s analyse how good it is.
It reduces your metabolism (which makes it harder to burn fat), it increases adrenal stress (which makes you fatter), it increases oxidative stress (which accelerates the aging process), it lowers the testosterone/cortisol ratio (making you fatter) and after 8 weeks, the effects plateau. As you can see, it is not only not the best tool for fat loss, it is actually counter-productive in many cases to the goals you want to achieve.
Let me ask you a question: Who has less body fat and looks better, generally; a sprinter or a marathon runner?
I think it’s clear who looks better, and it’s not difficult to understand why. We’ve all been sold on the idea, based on science from 20 years ago, that in order to burn fat you have to do long distance running. Sprinters do almost zero continuous, distance running, yet they have less body-fat, more muscle mass and have a generally more pleasing appearance. How is this possible? The reason is in the nature of their training!
Apart from their weight training sessions, they utilise a method called High Intensity Interval Training (HIIT).
What is it, you ask?
It is bouts of maximal effort, followed by bouts of recovery at a steady pace. It can be done on cardio equipment (X-trainers, bikes etc) or it can be done with equipment/bodyweight (burpees, sled pushes, bag flips etc) or simple sprinting. Due to the intense nature of HIIT, you only need to do it for a fraction of the time you would, distance running.
Instead of finding time to do an hour-long run, you can sneak off at lunch, do 15 minutes of intervals and burn a higher amount of calories (and fat!).
One of the main mechanisms we are aware of at the moment is a raise in what is called EPOC (Excess Post exercise Oxygen Consumption). Current research by exercise physiologist’s states that EPOC is not the only factor causing the raise in metabolism from HIIT, many of the specific mechanisms by which fat loss occurs over a 24-48hr period after performing it are not fully understood, but the results are, and that’s the take home message.
What are some other benefits? Due to the shorter training periods, it reduces the likelihood of (overuse) injury, it increases metabolism making you burn calories for significant periods of time after training, it promotes or maintains muscle mass, and is the best method for utilising fat as a fuel source, post workout. All of which distance running fails to do.
To summarise: distance running requires longer training sessions, which puts stress on your joints, increasing the likelihood of injury, it can actually make you fatter, and can make you age faster.
HIIT on the other hand, has shorter training sessions, which make it convenient and reduces the likelihood of injury, it raises metabolism, and promotes/maintains muscle mass (which is needed to burn fat)
In the end why would you want to use a fat loss method that is demonstrably inferior, causes more injuries, takes more time to do, and makes you look older? It doesn’t seem very rational to me.