Ever wondered why the distance runner is usually built like a stick insect and the sprinter is mostly defined muscle. This is because chronic cardio over stresses the adrenal glands, which secrete excess cortisol in turn leading to muscle breakdown in contrast to high intensity training which builds muscle mass, provided you don’t train too much.
For overweight people who are also dealing with insulin resistance, will have to deal with excess glucose that is released from the liver due to the presence of excess cortisol, in turn making it harder to lose fat and even cause fat storage when doing the wrong training like cardio.
High intensity training forces the muscles to adapt by becoming bigger and stronger and more efficient at using glucose for fuel.
Burning calories through cardio is not the best way to burn fat because the actual caloric burn of aerobic exercise is minimal, coupled with the fact that there is no growth hormone, fat burning and muscle building effect that you get with high intensity training.
How exactly should people be training?
Short bursts of intense exercise like sprints and lifting heavy things like weights otherwise known as resistance training.
Why is less is more when it comes to high intensity?
Exercise is not about pushing your body to the limit; it’s more about achieving hormonal and metabolic changes within the body that maximise fat burning and muscle toning with the minimum amount of stress on the body as possible.
Once you’re fit, you really don’t need frequent spurts of growth hormone production at least not from exercise; rather recovery takes precedence as being more important and your recovery period; it is more beneficial not exercising too frequently once you are in fit condition and here’s why; your adrenal gland sits right above your kidneys and it’s arranged in layers. On the outermost layers, you have mineral corticoids that control your sodium and your electrolyte levels. In the middle layer, you have your corticosteroids that control sugar and generate stress hormones (e.g. cortisol) and the inner most layer is where you generate growth hormones and the sex steroids.
If through too much high intensity exercise you’re hammering that adrenal gland, then instead of growth hormone spurt, you’re going to get in a cortisol spurt and you will defeat the purpose of the exercise as this will cause muscle breakdown and potential fat storage depending on whether you are overweight or not.
As we have previously alluded to, exercise can provide a valuable adjunct to accelerating fat loss as well as a multitude of other physical and mental benefits. However as we strive for the right balance we can overdo it and therefore it is important to listen to your body.