It is that time of year when all of the fitness mags shove six packs in our face and promise a summer sizzler of a workout regime to help you get your very own! Well, it is achievable for some certainly but as I have previously touched upon in my earlier article ‘Training on an Empty Tank’, it is more beneficial (and probably easier) to aim for a year round lean figure than a 6 week hot bod… I thought it would be interesting to cover the topic of ‘Cardio-Fasting’ as this could prove to be a useful tool in helping you get into lean shape!
Could you stomach a pre-breakfast run?Image: Andy Newson / FreeDigitalPhotos
What is Cardio Fasting?
In a nutshell, it is doing cardio exercise whilst your body is in a fasted state. For me, this is most easily achieved by heading out for a run first thing in the morning. Why would anybody want to do such a thing you may say! It isn’t for everyone and takes a good level of motivation to put yourself out there when you feel more like a zombie than a limber athlete but it is undoubtedly an effective way of getting your body into fat burning mode for a good part of the day.
Here’s the biological bit in a nutshell…when our bodies are in this fasted state, carbohydrate levels are depleted and therefore insulin blood levels are low – this helps with fat oxidation. It makes common sense – our bodies turn to fat reserves (and to some extent muscle tissue unfortunately) in order to create the energy it needs to exercise. Numerous studies have shown that high insulin levels will inhibit fat burning. No surprise that boxers, weightlifters and six-pack chasers have been exercising like this for many decades.
A word of warning…
The first obvious point to note is that exercising on an empty stomach is not wise if you do not feel comfortable (i.e. strong/energetic) doing it. Secondly, if you are likely to have a less productive session then maybe you would benefit from ingesting a few light calories (e.g. a pre-workout banana) before you exercise. Past studies have shown that exercise groups have in fact burnt more calories when working out after eating than without eating because they were able to work more intensively and for longer. It makes sense when we think that professional athletes would rarely perform in an with their energy levels depleted!
What type of exercise should we use for ‘cardio fasting’
The word cardio makes us think running, cycling and other breathless exercise but this is not necessarily going to get that fat burning most effectively. Personally, I’m not about to go on a long run without any substantial calorie intake – it wouldn’t be wise or effective because I would probably have to stop and walk. So if cardio is on the menu, keeping it intense and short will probably get the best from a cardio fasting session.
We should look to mix it up and not restrict ourselves to traditional cardio. Throwing in some pre-breakfast swimming or weight sessions is going to spark off effective fat loss just as much as going for a simple run.
A final thought…
Whilst it is a contradictory topic, this article hasn’t been a waste of words. Cardio fasting does not work effectively for all of us but if hunger pangs are not going to stop you from putting in a good training session then it can be a very effective fat loss tool indeed! Personally, I like to use it with my morning short running because so long as I am hydrated, I find that I can sustain a good pace for between 5-10km distances and I do not get sluggish as I have noting in my belly to cause stomach upsets! You may really enjoy the upbeat feeling you get long into the day after a morning workout – so no excuses for falling asleep at your desk!
Lyle McDonald has written a very thorough and scientific account of this subject over at Body Recomposition.