What’s the best exercise for calorie burning? Running? Rowing? Bike? Well they definitely can all be useful. However, the fundamental question is do you need to do cardiovascular exercise to lose weight? Well the physiques of Olympic level marathon runners and cyclists are pretty lean, saying that though sprinters are pretty lean and in comparison, although they perform a great deal less volume of training in comparison in regards to hours of performing “cardiovascular exercise.” Cardiovascular exercise it seems is at a bit of a point where definitions are flaky at best. For instance someone says “I don’t do cardio- I lift weights and circuit train.”
Well simply this is cardio- in my mind anything that gets you out of breath could be classified cardiovascular as there are greater stresses placed upon the cardirspiratory system. Here it is a question of intensity and load. Perform 10 burpees and you may be out of breath, indeed perform burpees for as long as you can and ultimately you will feel fatigue which will limit the performance of the exercise. As exercise intensity increases the volume of exercise that can be performed is limited. The higher the intensity the less you can do in effect. While not rocket science it certainly does not mean that interval/ high intensity training is the be all and end all. What matters is that the method of training is specific enough to overload the desired system of the body.
Here’s the Science Bit… If the major goal is to break down body fat we need a number of things to be aligned. Firstly, we need a number of things to be happening in the body. We are always turning over calories- be it stored fat or carbohydrate. What matters here is that what is being reabsorbed or restored is not as much as being burnt. Activity causes this burning of energy. Initially, we will preferentially burn through our stored carbohydrate stores, once these are gone we will move over to our stored fat stores. We will always be burning a mixture of both- however if we have depleted store of carbohydrate then the body burns fat to be used as energy. This highlights the usefulness of low carb diets for fat loss (though there are a lot of weight losses that are not body fat- weight loss does not always mean body fat reductions as muscle glycogen is reduced as is stored body water).
Secondly, we need to stimulate fat breakdown- two things do this. Exercise of a higher intensity stimulates a higher hormonal response stimulating a faster breakdown of fat stores, if we are in need of energy this will also break down stored energy sources.
A Question of Efficiency… So why currently does cardiovascular exercise get a bashing? Well it’s a question of efficiency. If you do the same thing repeatedly you become more efficient. Running, rowing, biking and swimming are all great examples of exercises where you perform repetitive movements. Repetition breeds efficiency- efficiency means less effort to sustain a higher intensity. Therefore changes in intensity don’t have as large effect as efficiency improves.
So What’s the Deal?… Are intervals effective for fat loss? Yes and no- elevating intensity causes a higher initial call for the body to provide energy though this does not necessarily need to be a 20 second Tabata sprint, 20 jump squats or 100m run. What matters here is the intensity and with all of the above you can only do a few sets well before intensity is hampered.
So shall we do no steady state?… Well if we have performed enough activity to stimulate fat breakdown initially then steady state will be ideal for burning released energy. In individuals new to exercise steady pace exercise may provide enough stimulus. More advanced exercisers will have to hold a higher intensity to give the same effect. Also in turn if you perform enough “activity” then you will burn through all stored energy unless diet contains a ridiculous amount of calories.
If we become efficient then does this hamper fat burning?… This is the take home point for me- possibly because our tolerance to intensity firstly and secondly to the efficency of the movement or activity performed. As a valid point of observation there are plenty of amateur runners and cyclists with a level of body fat which seemingly does not correlate with their level of activity (food intake is obviously important and I will address this in future posts).
Therefore should all “cardio” for fat loss be randomized to limit efficiency? Possibly a model of all methods should be fused together after all kettlebells won’t instantly make you thin but using them in a focussed way they can be a great tool. What matters in my mind is that periods of training are directional. Fat loss is one of those goals where you have to focus in on the primary goal. What holds true is that any exercise programme prescribing activity will cause extra calorific burn. Programming needs to be varied though to keep stimulating the body to adapt and change. Without these changes “exercise efficiency” only improves and sometimes for fat loss this is not always the best way to optimize your results.