Fat loss through low-intensity cardio is not the most effective method of losing body fat, though many do not know this. According to SF Weekly, fat loss is aided through an increase in metabolism, low intensity cardio does not increase metabolism, though it is quite effective at burning calories. As the ability to burn fat and raise metabolism can be achieved through HIIT (High-intensity interval training).
HIIT cardio is, therefore, more effective, when it comes to fat loss, as not only does it burn calories but also increases the body’s overall metabolism. HIIT targets fat moreover low-intensity cardio, after doing HIIT the body will continue to burn calories post-exercise.
Studies of HIIT cardio
Researchers are able to measure the rate of metabolism change post-exercise using EPOC (Exercise Post Oxygen Consumption). Body cells require more oxygen when metabolism increase occurs.
The same researchers conducted two studies, published in Int J obes Relat Metab Discord. 2001 Mar, 25(3): 332-9. The initial study was conducted on two groups of 352 men total, those who did not do high-intensity activities on a regular basis and those who did. Even when eating more than the idle group. Men performing high-intensity activities had lower subcutaneous fat and body fat percentage. The second study measured the effects of high-intensity exercise. Fat oxidation and oxygen consumption increased as a result. The high-intensity group, on average, consumed more oxygen than the low-intensity group. Propranolol was shown to stop these effects. Researchers concluding then that beta-adrenergic stimulation may play a vital part in the post-high intensity exercise effects.
Another study concerning metabolism.1994 Jul; 43(7): 814-8 compared a group consisting of 5 women and 5 men doing HIIT and a group of 9 men and 8 women each doing 20-week endurance-training. The reduction in subcutaneous skinfolds by those doing HIIT was 9 times greater than the endurance group! What it comes to skeletal muscle, researchers suggest that higher intensity is far superior.
Should I do HIIT cardio with bodybuilding?
Extremely fit people tend to do HIIT cardio as it is very intense cardio. Even physically fit people may find it very tiring. Some bodybuilders prefer to walk on a treadmill or bicycle at a steady pace, as opposed to doing HIIT. HIIT cardio can save time, only being a third as long as lower intensity cardio sessions. HIIT cardio can be too catabolic (muscle wasting), especially for hard gainers with naturally fast metabolisms. Leg muscle mass can be maintained by doing leg exercises such as running or biking. It is possible for leg muscles to shrink if the muscle fiber type composition changes, as a result of doing low-intensity cardio as opposed to HIIT. Muscle fiber type changes, caused by low-intensity cardio, can be avoided with weight training during any fat loss cycles.
If your glucose levels drop during HIIT cardio, the body may eat into your hard-earned muscle; this can be avoided by eating a meal before exercising. Protein can be utilized as an energy source, HIIT requires quick energy and so when glucose is depleted it uses protein as an alternative energy source. Low-intensity cardio is usually performed after rising; this is because it does not have as much of a metabolism-burning effect. After rising, glycogen stores are rather depleted and the body is in an optimal state for fat burning during exercise. Burning carbs is the result when doing low-intensity cardio after eating. A calorie deficit will be created either way but is more effective after rising. After rising, you can take advantage of the fat-burning mode your body will be in, rather than merely burning calories. Fat loss is mainly due to calories consumed vs. expelled, so burning calories or fat will not make much of a difference in the long run, though it can help to burn fat overall.