1. It is very poor at improving body composition or fitness level
Optimal body composition
Low body fat and appreciable quantity of muscle mass. Everybody can agree with this, even though there is bound to be some disparity in the amounts of both. Traditional cardio has been used since the ‘60s, when Dr. Kenneth Cooper launched the fitness craze with his books titled ‘Aerobics’, ‘More Aerobics’ and ‘Aerobics for Women’, based on his research.
He is the originator of the jogging movement and maintained that optimal body composition and fitness could be obtained solely through cardio.
The rationale behind that was that cardio increase mitochondrial density and thus, the capacity to burn fat in the cells. The mitochondria are tiny little organelles in the cell that are responsible to produce energy by burning fat in the presence of oxygen, a process known as cellular or aerobic respiration (aero- means air in greek).
So the more mitochondria, the more fat burning, the better your capacity to produce energy and the better you look and perform, right? Absolutely.
Short sprints and short rest intervals done in a repeated fashion have consistently out-performed long distance aerobic activity in the ratio of productive results vs. time invested
The problem is, research has shown that sprinting, or anaerobic activities (anaerobic means without the use oxygen) are way better at upregulating mitochondrial biogenesis. Short sprints and short rest intervals done in a repeated fashion have consistently out-performed long distance aerobic activity in the ratio of productive results vs. time invested.
One study even looked at 4 seconds treadmill sprints with 20 seconds active rest. That’s less time than most people take to lace their shoes to go out jogging!
As a bonus, it leaves plenty of time and energy to develop your muscles through another anaerobic activity: serious weight training!
If you want to keep using mostly aerobic energy system, or V02max in the parlance of the field, the intensity of the exercise is limited. If you go more intense, you’ll start using the other energy systems of the body: the anaerobic energy systems. Those systems produce energy more rapidly than the aerobic system, but they do not use fat to do so. However, the process of using them during exercise triggers greater fat loss via increases in many of the body’s metabolic pathways.
This is where the traditional cardio myth is even more useless; it prevents people from using other energy systems properly in order to stay in the so-called ‘fat burning zone’, thus promoting longer and more frequent cardio sessions, promoting a vicious cycle: want to lose more weight (unfortunately not just fat)? Then you have to run/pedal/swim longer.
This is in spite of the fact that short sprint intervals and burst-type activities have been demonstrated as more effective for fat burning, and they take only a few minutes of actual work each time. The most famous protocol for this is the 20/10, invented by Professor Izumi Tabata. His methodology became so famous that these sprints are now simply known as ‘Tabatas’. They consists of 20 seconds of all-out, balls to the wall cycling, with 10 seconds of active recovery. Do this 8 times in a row, for a total of 4 minutes.
The biggest problem I see right now, is that people are very, shall we say, ‘conservative’ when it comes to the definition of ‘balls to the wall’. In my book, your face should be turning a pastel type of green and your spleen coming out of your left eye socket on each of the rounds. Otherwise, you’re cutting corners and preserving energy for latter rounds. Of course, there are other less extreme protocols, especially since this one was tested on Japanese Olympic athletes, but the results for only 4 minutes of work were dramatic: every markers of energy system performance, including aerobic power and capacity, when up.
So even though you might choose a different sprinting methodology, you can increase your aerobic power and capacity and lose more body fat in a much shorter time span.
So the lesson is this: ditch the hamster wheel and start sprinting…. Repeatedly. You’ll look and feel much better, and be able to demonstrate it too.