Tag Archives: energy system

Cardiotraining: Are you training hard enough?

Cardiotraining training is an essential part of a healthy and effective training program and can be used to achieve multiple goals. When performed correctly it strengthens the heart, increases quality of blood vessels and lungs. Therefore it is very useful for people suffering cardiovascular disease, diabetes mellitus (especially type 2) and COPD, but it is most often used to increase endurance or to lose weight.

The important question is however, how do I know if my cardiovascular workout is performed at the right intensity? An often heard and persistent fairy tale is that for losing fat, low intensity training is the most effective. This is not right however, and many studies show that higher intensity workouts result in larger amounts of fat loss and larger increases in endurance and oxygen uptake.

To determine the right intensity, it is possible to use a heart rate monitor and calculate the right heart frequency, but this requires a good quality heart rate monitor. Another simple way is to check if talking during training is still possible. When someone can continue conversation, the body apparently has enough oxygen to allow disruption of air flow for talking and no real training occurs. When only a few words can be spoken at a time during training, while breathing heavily, training is far more effective. The reason for this is that the body needs almost all oxygen to go to the muscles to maintain exercise.

When no more air is available to speak, the aerobic system is completely active and the anaerobic system has to deliver the energy that the aerobic system is not able to generate. As the body strives for balance and anaerobic metabolism disrupts this balance by for example an decrease in pH, it will improve aerobic function so it is better able to meet training demands. This will increase the intensity at which someone gets trouble speaking and it will stimulate resting metabolic rate and fat metabolism, making weight loss easier. When one is not able to speak during training, training intensity is high enough to receive the benefits of cardiovascular training, which do not occur at lower intensity.


Aerobic System

The aerobic system, also called the oxidative system (aerobic means a proces which functions with the aid of oxygen) is the most important source of ATP in rest and during lower intensity exercise. This system generates ATP from both carbohydrates and fats. When the carbohydrate stores are depleted protein can also be used. Depending on the intensity of exercise, a certain ratio of carbohydrates and fats is used. At rest this ratio is around 70% fat and 30% carbohydrates. When exercise starts, the use of fat as an energy substrate decreases and carbohydrate use increases with the increase in intensity. When intensity rises to 100% VO2max, almost all ATP will be generated from carbohydrates.