To determine the shape of the athlete, a special indicator of VO2 max is used. Find out what it is. Here is a detailed explanation from a scientific point of view. Any athlete is trying to find a way to improve the effectiveness of their training. This is typical not only for professionals, but also for amateurs. Long distance runners need to have a high endurance score to be able to withstand the intense stress they experience during long distance races.
Scientists have been manipulating various physiological parameters for more than three decades to improve the effectiveness of training. However, there are still significantly more questions than answers. Many modern methods were created due to numerous errors, but at the same time, only a small part of them have a scientific basis.
For quite a long time, the VO2 max (maximum oxygen consumption) indicator is used to build the training process and it is with its help that the performance and progress of the athlete is determined. However, the question often arises of the need to use this parameter. Today we will explain why VO2 max is important for runners.
VO2 max: what is it and how to decode
People interested in running have probably heard about the incredible values of this parameter in pro athletes. Let's say Lance Armstrong has a VO2 max of 84 ml / kg / min. However, the question arises - to what extent these figures can be trusted and whether it is worth doing it at all. Without going into scientific terminology, the answer is no.
Contrary to popular belief, VO2 max is a simple measurement and cannot fully indicate an athlete's fitness level or potential. If we use only this indicator to determine the fastest among several runners, then we will not be able to do this.
The fact is that this indicator is not able to accurately reflect the most important processes - the transport and utilization of oxygen in muscle tissues. To understand what this is about, you should learn more about VO2 max. This is what we are going to do now. For the first time the concept of "maximum oxygen consumption" was described and began to be used in the twenties. The main postulates of this theory were:
- There is an upper limit for oxygen consumption.
- There is a significant difference in VO2 max.
- An athlete must have a high VO2 max in order to successfully overcome medium and long distances.
- The limiting factor for VO2 max is the ability of the cardiovascular system to deliver oxygen to muscle tissue.
To calculate this indicator, a simple subtraction of the amount of exhaled oxygen from the amount of oxygen absorbed is used. Since VO2 max is used to quantify the volume of an athlete's aerobic system, it is influenced by various factors.
Today scientists use the following formula to calculate this indicator - VO2 max = Q x (CaO2 - CvO2), in which Q is cardiac output, CaO2 is the amount of oxygen in the arterial bloodstream, CvO2 is the amount of oxygen in the venous bloodstream. The equation we are considering takes into account the volume of blood that is pumped by the heart muscle, as well as the difference in the amount of oxygen entering and leaving the muscle tissue. While VO2 max is not important for practical purposes, an increase in this ability does have some impact on an athlete's performance.
In turn, the ability to absorb and utilize oxygen depends on various factors that can be seen along the entire path of oxygen movement through the body. Understanding the importance of VO2 max for runners requires understanding the movement of oxygen from the lungs to the mitochondria. Scientists call this pathway the oxygen cascade, which consists of several stages.
- Oxygen consumption. After inhalation, oxygen enters the lungs and its way along the tracheobronchial tree, resulting in capillaries and alveoli. With their help, oxygen is in the bloodstream.
- Oxygen transport. The heart muscle throws out blood, which enters the organs and tissues of our body. Oxygen enters the muscles through a network of capillaries.
- Oxygen utilization. Oxygen is delivered to the mitochondria and used for aerobic oxidation. In addition, it takes an active part in the electrolyte transport chain.
Respiratory system impact on VO2 max?
The human respiratory system is responsible for the process of oxygen entering the blood. From the oral and nasal cavities, air enters the lungs and begins its movement along the bronchi and bronchioles. Each bronchiole at the end has special structures - alveoli (respiratory sacs). It is in them that the diffusion process takes place, and oxygen is in the network of capillaries, which tightly entwine the alveoli. After that, oxygen moves to the larger blood vessels and ends up in the main bloodstream.
The amount of oxygen entering the capillaries from the respiratory sacs directly depends on the pressure difference between the vessels and the alveoli. Also, the number of capillaries is of great importance here, which increases as the athlete's fitness level increases.
It is quite obvious that the amount of oxygen used directly depends on the running speed. The higher it is, the more actively the cellular structures of muscle tissues work and they need more oxygen. An athlete with an average level of training develops a speed of about 15 km / h and consumes about 50 milliliters of oxygen per minute for each acidic body weight.
But VO2 max cannot go up indefinitely. In the course of research, it was found that at a certain rate, a plateau sets in, and the indicator of maximum oxygen consumption no longer increases. The presence of this peculiar physiological border has been proven in the course of numerous experiments and is not questioned.
If you want to know why VO2 max is important to runners, there is one important factor to consider regarding training intensity. Even if the athlete works hard, the oxygen saturation of the blood cannot fall below 95 percent. This tells us that the consumption and transport of oxygen from the lungs to the bloodstream cannot limit the performance of the athlete, because the blood is well saturated.
At the same time, scientists have discovered in experienced runners a phenomenon called "arterial hypoxia." In this state, the oxygen saturation of the blood can drop to 15 percent. There is a direct relationship between VO2 max and blood oxygen saturation - a decrease in the second parameter by 1 percent, leads to a drop in the second by 1–2%.
The cause of the phenomenon of "arterial hypoxia" has been established. With a powerful cardiac output, blood quickly passes through the lungs, and does not have time to be saturated with oxygen. We have already said that VO2 max is influenced by the number of capillaries in the alveoli, the rate of diffusion and the strength of cardiac output. However, here it is necessary to take into account the work of the muscles taking part in the breathing process.
This is due to the fact that the respiratory muscles also use oxygen to carry out their work. During training with an experienced athlete, this figure is about 15-16 percent of the maximum oxygen consumption. There is another reason for the ability of the respiration process to limit the runner's performance - the competition for oxygen between skeletal and respiratory muscles.
Simply put, the diaphragm is able to take up some of the oxygen that, as a result, does not reach the leg muscles. This is possible when running intensity is 80 percent of VO2 max. Thus, the conditionally average intensity of running can cause fatigue of the diaphragm, which will lead to a drop in the oxygen concentration in the blood. In the course of research, the effectiveness of breathing exercises has been proven to improve the performance of runners.
How does oxygen transport affect VO2 max?
Since the introduction of VO2 max, scientists have believed that oxygen delivery can limit VO2 max. Moreover, today this influence is estimated at 70-75 percent. It should be recognized that the transport of oxygen to tissues is influenced by many factors.
First of all, we are talking about the adaptation of the heart muscle and the vascular system. Cardiac output is considered to be one of the strongest limiters of VO2 max. It depends on the stroke volume of the heart muscle and the frequency of its contractions. Maximum heart rate cannot be changed during training. But the stroke volume at rest and under the influence of physical exertion is different. It can be increased by increasing the size and contractility of the heart.
The second most important factor in oxygen transport is hemoglobin. The more red cells in the blood, the more oxygen will be delivered to the tissues. Scientists have done a lot of research on this topic. As a result, we can safely say that the concentration of red cells in the blood has a significant impact on the VO2 max.
Actually, this is why many athletes use drugs to speed up the production of red cells. They are often referred to as "blood doping". Quite a lot of scandals in sports have been associated with the use of these particular means.
How do I increase my VO2 max?
The fastest way to increase this indicator is to run for six minutes at maximum speed. Your training process in this case may look like this:
- Warm up lasting ten minutes.
- Run for 6 minutes at maximum speed.
- 10 minute rest.
However, this method is not the best, because the athlete can get very tired after such a workout. It is better to put a little less effort on a certain time interval, which will be separated by periods of recovery. We suggest starting your workouts using the 30/30 pattern. After a ten-minute warm-up (jogging) for 30 seconds, work at maximum intensity, and then move at a slow pace for the same length. To increase VO2 max, the 30/30 and 60/60 regimens are optimal.
If you have sufficient training experience, then you can use the so-called lactate intervals. After warm-up at a high pace, cover the distance from 800 to 1200 meters and switch to a slow run (400 meters). However, remember that lactate intervals should only be used by well trained runners.
