Every gym has its own Low Intensity Cardio enthusiasts running endlessly on the treadmill for hours eager to stay fit, lose weight and trim down. Media, advertising and even a lot of personal trainers and fitness experts have recommended hours of long cardio workouts to burn zillions of calories and shred unwanted weight. I find that generally most people believe that when it comes to exercise that more is better and as soon as people start to plateau with their weight loss they often automatically try to obtain a solution by increasing the overall duration of the workouts.
It would be wise to stop and reflect on whether the advertising companies of expensive cardio equipment are cashing in on our health as when you think about it, good old dumbbells, Olympic bars and weight plates are incredibly durable and have a long life, they don’t break or fall apart or get electrical difficulties or need the belts replacing, they are far more cost effective than treadmill, stair climbers, bikes and rowers that require regular repair and maintenance.
During low intensity Aerobic exercise, the majority of the energy being supplied to the muscles is generated by the Aerobic metabolism of Fats because there is an adequate amount of oxygen present to achieve this, however, at a much higher intensity, the ability to deliver Oxygen is greatly reduced shifting the body into an Anaerobic state which primarily uses Carbohydrates to produce the necessary energy.
Though at first glance cardio/aerobic training looks appealing as a good method of fat loss, there is more to the story than meets the eye when comparing the benefits of high and low intensity training. For example, long slow intensity workouts can actual compromise muscle retention causing a decrease in Metabolism whereas higher intensity workouts, though not burning as much fat during a workout can actually burn a higher number of calories while actually increasing the bodies growth hormone allowing the potential for an increase of muscle mass.
Of course, larger muscles burn more calories and raise the metabolism even when the body is at rest, in fact it has been estimated that the body has the ability to continue to burn fat after resistance training for up to 72 hours after a workout has been completed.
Though when a deconditioned person begins a cardio program they will achieve a good amount of primary weight loss, It is important to take note of the fact that long duration exercises repeated over and over again is stress to the body and if you are already suffering from a stress induced life caused by long hours in the office, frequent travelling, business meeting, rushing around taking care of the children, cleaning the house, doing the laundry the adding more and more stress to the already stressed out body, then this can be a recipe for disaster. Too much stress on the adrenals will cause a rise of Cortisol levels which will deplete liver Glycogen and cause blood sugar levels in the blood to rise, this in turn can eventually lead to insulin resistance and of course a greater storage of fat!
The next question that we need to ask ourselves is did our ancestors participate in slow long distance running whilst collecting firewood and berries or hunting and farming the land? I think not as it would be a waste of energy expenditure and in modern day living, how much demand is there in our daily lives for slow low intensity runs other than recreational marathons, is it still a waste of our energy expenditure?
Functional exercises and explosive training can be much more desirable as it can help you to implement strength, flexibility and core stability into pushing, pulling, lifting and bending movements that we use on a daily basis.
In addition to the added stress, research has shown that excessive amounts of cardio can also suppress the production of T3 by the Thyroid causing symptoms of Hypothyroidism which can actually also result in weight gain and in addition to this when you are expending energy for long periods of time on cardio, your metabolism stimulus tries to gradually adapt by slowing down to preserve necessary energy for survival. A reduction in metabolism means you can no longer eat as much before you start gaining weight.
So it may have sounded like this article is primarily against low intensity Cardio workouts but actually its all about balance, fast walking for example would be a really good starting point for the elderly, obese, a total beginner, someone with injury or someone who is very de-conditioned.
Regular aerobic training would be fine as long as you are not currently stressed or overworked and as long as your willing to switch up your training once the metabolic stimulus has been reduced.
Overtraining of any kind should always be avoided and many people fall into this category when they over-exercise and under-eat which is catabolic and creates muscle wastage, so make sure workouts have scheduled rest intervals and finally to really maximize your results during training then consider switching up some of the long cardio workouts for shorter high intensity interval workouts and see the difference this can make to your physique.
A good example would be doing run sprint intervals as fast as you can to activate your fast twitch muscle fibers for short periods and If you have a good level of fitness, strength and flexibility then Incorporate Plyometric training to really blast the fat, this can include high intensity speed jumps such as star jumps, squat jumps, hops, skipping and box jumps.