VO2 max as an indicator of physical fitness and athletic prospects. Examples of workouts to increase VO2 max

Without modern knowledge about the work and functioning of the human body under maximum load, success in sports for any athlete is impossible, especially in running.

Knowledge about VO2max is needed not only by athletes, but also by ordinary people, since this indicator reveals the secrets of the health status of any person. this moment, the capabilities of the body, its ability to live a long life.

What is vo2 max?

VO2 Max is defined as the maximum amount of oxygen your body can take in, deliver, and use in one minute. It is limited by the amount of oxygen in the blood, which the lungs and the cardiovascular system can process, and the amount of oxygen that muscles can extract from the blood.

The name means: V - volume, O 2 - oxygen, max - maximum. VO 2 max is expressed either as an absolute rate of liters of oxygen per minute (l/min) or as a relative rate in milliliters of oxygen per kilogram of body weight per minute (e.g. ml/(kg min)). The latter expression is often used to compare the performance of endurance athletes

What does it characterize?

VO2max is a measure of the maximum rate at which an athlete's body is able to absorb oxygen while performing a specific activity, adjusted for body weight.

It is estimated that VO2 Max decreases by approximately 1% per year.

A high VO2max is important because it is closely related to the distance covered by the test subject. Research has shown that VO2max accounts for approximately 70 percent of race performance success among individual runners.

So, if you are able to run 5000m one minute faster than I can, it is likely that your VO2max is higher than mine by an amount that is sufficient to account for 42 seconds of that minute.

There are two main factors that contribute to a high VO2max. One of them is strong oxygenation transport system which includes a powerful heart, hemoglobin in the blood, high blood volume, high capillary density in the muscles, and high mitochondrial density in the muscle cells.

The second speed is the ability to compress a large amount muscle fibers at the same time, since the more muscle tissue active at any given time, the more oxygen the muscles consume.

This makes VO2 Max a critical marker of aging, which we can measure and improve through proper aerobic training. To do this you must raise your heart rate to between 65 and 85 percent of your maximum through aerobic exercise for at least 20 minutes, three to five times a week.

Differences in indicators between ordinary people and athletes

U ordinary people men aged 20-39 years VO2max on average from 31.8 to 42.5 ml/kg/min, and runners of the same age have VO2max values ​​on average up to 77 ml/kg/min.

Untrained girls and women tend to have a maximum oxygen uptake that is 20-25% lower than that of untrained men. However, when comparing elite athletes, the gap tends to be close to 10%.

Going further, VO2 Max is adjusted for lean mass in elite male and female athletes, the differences disappearing in some studies. Sex-specific substantial fat stores are hypothesized to account for the majority of metabolic differences in running between men and women

Typically, age-related declines in VO2 max can be explained by reductions in maximum heart rate, maximum blood volume, and maximum a-VO2 difference, that is, the difference between the oxygen concentration in arterial blood and venous blood.

How is Vo2 max measured?

Accurate measurement of VO 2 max involves physical effort of sufficient duration and intensity to fully charge the aerobic energy system.

In general clinical and sports testing, this typically involves a graded exercise test (either on a treadmill or stationary bicycle) in which the exercise intensity is gradually increased while measuring: ventilation and oxygen, and inhaled and exhaled carbon dioxide concentrations .

• VO 2 max is achieved when oxygen consumption remains stable despite increased work volume.
• VO 2 max is correctly determined by the Fick equation:
• VO2max=Q x (CaO2-CvO2)

These values ​​are obtained during exercise at maximum effort, where Q is the cardiac output of the heart, C O 2 is the arterial oxygen content and C V O 2 is the venous oxygen content.

• (C O 2 - C v O 2) is also known as the arteriovenous oxygen difference.

In running, it is usually determined using a procedure known as a test additional exercises, in which the athlete breathes into a tube, and a device with a tube collects and measures exhaled gases while running on a treadmill, where

The belt speed or gradient is gradually increased until the athlete reaches fatigue. Maximum speed The oxygen consumption recorded in this test will be the runner's VO2max.

Calculation of VO 2 Max without fitness test.

To determine your heart rate without a monitor, place two fingers against the artery on the side of your neck, just under your jaw. You should be able to feel your heartbeat in your fingers. Set a timer for 60 seconds and count the number of beats you feel

This is your heart rate (heart rate) in beats per minute (BPM). Calculate maximum heart rate. The most common way to calculate your maximum heart rate is by subtracting your age from 220. If you are 25 years old, your HR max = 220 -25 = 195 beats per minute (bpm).

Let's determine VO 2 max using a simple formula. The simplest formula to calculate VO 2 Max is VO 2 Max = 15 x (HR Max / HR rest). This method is considered good when compared with other general formulas.

Calculate VO 2 max. Using rest and maximum heart rate you have already determined, you can plug these values ​​into the formula and calculate VO 2 max. Let's say your resting heart rate is 80 beats per minute and your maximum heart rate is 195 beats per minute.

• Write the formula: VO 2 max = 15 x (HR max / HR rest)
• Connect the values: VO 2 max = 15 x (195/80).
• Solve: VO 2 max = 15 x 2.44 = 36.56 ml/kg/min.

How to Improve Your VO2max

A quick way to improve your VO2max is to run for about six minutes at the fastest pace you can sustain for that time. So you could do VO2max workouts that consisted of a 10-minute warm-up, a six-minute run time, and a 10-minute cool-down.

But this is not the most The best way VO2max training, as you may become very tired after a six-minute effort. It's better to do a little less effort on the same thing or a little more high intensity separated by recovery periods, as this allows the athlete to use more total time at 100 percent VO2max before reaching exhaustion. Another option is to add the intensity back just a little, and do slightly longer intervals.

Start with 30/30 intervals. After warming up for at least 10 minutes with light jogging, work hard for 30 seconds at the fastest pace. Then it will slow down to easy Good way introduce VO2max training into your program at 30/30 and 60/60 intervals. Continue in alternating fast and slow 30-second sections until you have completed at least 12 and then 20 of each.

Some time ago we smart watch Withings, who learned how to measure VO2 max. If you are serious about fitness, you have probably come across these concepts at some stage of your training. But what does it mean?

VO2 max is the maximum amount of oxygen a person can use. In other words, it is a measurement of your ability to consume oxygen. Moreover, this great way determine the strength of the cardiovascular system. People with high VO2 max levels have better blood circulation, which means it is more efficiently distributed to all the muscles involved in physical activity.

How is VO2 max measured?

This indicator is the sum of the number of milliliters of oxygen consumed per minute per body weight. Professional athletes undergo this test in special laboratories on a treadmill. During the test, the amount of oxygen required by the athlete is determined, including at those moments when the intensity of the load increases. Usually the process takes about 10-15 minutes.

As for the Withings Steel HR Sport watch, VO2 max is determined using data from your workout speed and heart rate.

Highest VO2 max

The highest rate was recorded for cyclist Oskar Svendzen, it was 97.5 ml/kg/min. Generally, top scores shown by representatives of those sports that require special endurance. Statistically, rowers and runners have the highest V02 max levels of any athlete.

What affects V02 max performance

Genetics and physical training play a huge role. However, there are several other factors that determine a person's VO2 max to some extent.

• Gender: In general, women's VO2 max levels are about 20% lower than men's.
• Height: The shorter a person is, the higher his performance.
• Age: The maximum level is recorded between the ages of 18 and 25 years, after which it decreases.

You can also improve your V02 max by increasing the duration and intensity of your workout, or simply starting to exercise if you haven't already. And as you become more experienced, you need to gradually increase the intensity of your training.

On our website - about the concept of VO2max, breathing while running and how this information can be usefully used by an ordinary runner like you and me.

Runners of all levels, from dedicated amateurs to professionals, are looking for ways to enhance their training to improve their performance and set new records.

Running on long distances requires the athlete to perform a large amount of endurance training to overcome constant physiological stress. Various ways Physiological parameters have been manipulated to improve endurance and performance in runners for over 30 years, although many questions remain (1). Most of the methods known today arose as a result of numerous trials and errors, and only a few of them received a clear scientific basis (2, 3, 4).

For a long time, the maximum oxygen consumption (VO2max) indicator has been used as a kind of “magic bullet”, allowing you to build training based on its value and analyze the performance and progress of the athlete. But is it that good, is it suitable for everyone and can you rely on it?

It is believed that for any passionate runner, VO2max (or VDOT in Daniels) actually determines his talent or potential. VO2max measures your maximum oxygen consumption (VO2 max) and is one of the most commonly used metrics to track your training progress. Of course, we have all heard about the incredible VO2max numbers of many professional athletes: Lance Armstrong (84 ml/kg/min), Steve Prefontaine (84.4 ml/kg/min), Bjørn Dæhlie (96 ml/kg/min) and many others.

But is it necessary to pay such close attention to these numbers? In short, no.

Contrary to popular belief, VO2max is just a measurement and does not indicate an athlete's fitness or potential. In fact, among several trained runners, it is impossible to determine who is the fastest based on VO2max alone.

Measuring VO2max does not accurately reflect the critical processes of oxygen transport and utilization in muscles. Let's first try to carefully consider this indicator, its components, as well as the impact that various stages of oxygen transport have on VO2max.

VO2max concept

The term “maximum oxygen uptake” was first described and used by Hill (5) and Herbst (6) in the 1920s (7). The basic principles of VO2max theory were:

• There is an upper limit on oxygen consumption,
• There is a natural difference in VO2max values,
• A high VO2max is necessary for successful participation in middle and long distance races,
• VO2max is limited by the cardiovascular system's ability to transport oxygen to the muscles.

VO2max measures the maximum amount of oxygen used and is calculated by subtracting the amount of oxygen exhaled from the amount of oxygen ingested (8). Because VO2max is used to quantify the capacity of the aerobic system, it is influenced by a large number of factors along the long pathway of oxygen from the environment to the mitochondria in the muscles.

Formula to calculate VO2max:
VO2max=Q x (CaO2-CvO2),

where Q is cardiac output, CaO2 is the oxygen content in arterial blood, CvO2 is the oxygen content in venous blood.

This equation takes into account the volume of blood pumped by our heart (cardiac output = stroke volume x heart rate), as well as the difference between the level of oxygen in the blood flowing to the muscles (CaO2 - arterial oxygen content) and the level of oxygen in the blood. flowing from the muscles to the heart and lungs (CvO2 - oxygen content in venous blood).

Essentially, the difference (CaO2-CvO2) represents the amount of oxygen absorbed by the muscles. While measuring VO2max is of little value for practical purposes, developing the ability to consume and utilize oxygen more efficiently impacts a runner's performance. The absorption and utilization of oxygen, in turn, depend on a number of factors that occur along the long path of oxygen.

The movement of oxygen from atmospheric air to mitochondria is called the oxygen cascade. Here are its main stages:

• Oxygen consumption

Air entering the lungs
- Movement along the tracheobronchial tree to the alveoli and capillaries, where oxygen enters the blood

• Oxygen transport

Cardiac output - blood flows to organs and tissues
- Hemoglobin concentration
- Blood volume
- Capillaries from which oxygen enters the muscles

• Oxygen utilization

Transport to mitochondria
- Use in aerobic oxidation and electron transport chain

Oxygen consumption

The first stage of oxygen's journey is to enter the lungs and the bloodstream. Ours is mainly responsible for this part respiratory system(Fig. 1).

Air enters the lungs from the oral and nasal cavities due to the pressure difference between the lungs and the external environment (in external environment the oxygen pressure is greater than in the lungs, and oxygen is “sucked” into our lungs). In the lungs, air moves through the bronchi to smaller structures called bronchioles.

At the end of the bronchioles there are special formations - respiratory sacs, or alveoli. Alveoli are the place of transfer (diffusion) of oxygen from the lungs into the blood, or more precisely into the capillaries that entwine the alveoli (Imagine a ball entangled in a web - these will be the alveoli with capillaries). Capillaries are the smallest blood vessels in the body, their diameter is only 3-4 micrometers, which is less than the diameter of a red blood cell. Receiving oxygen from the alveoli, the capillaries then carry it to larger vessels, which eventually empty into the heart. From the heart, oxygen is carried through the arteries to all tissues and organs of our body, including muscles.

The amount of oxygen entering the capillaries depends both on the presence of a pressure difference between the alveoli and capillaries (the oxygen content in the alveoli is greater than in the capillaries) and on the total number of capillaries. The number of capillaries plays a role, especially in well-trained athletes, as it allows more blood to flow through the alveoli, allowing more oxygen to enter the blood.

Rice. 1. The structure of the lungs and gas exchange in the alveoli.

Oxygen usage or demand depends on running speed. As speed increases, more cells in the leg muscles become active, the muscles need more energy to maintain the thrusting movement, which means the muscles consume oxygen at a higher rate.

In fact, oxygen consumption is linearly related to running speed (higher speed means more oxygen consumed, Fig. 2).

rice. 2. Relationship between VO2max and running speed. On the horizontal axis – speed (km/h), on the vertical axis – oxygen consumption (ml/kg/min). HR – heart rate.

The average runner running at 15 km/h will likely consume oxygen at a rate of 50 ml per kilogram of body weight per minute (ml/kg/min). At 17.5 km/h, the consumption rate will increase to almost 60 ml/kg/min. If a runner is able to reach a speed of 20 km/h, oxygen consumption will be even higher - about 70 ml/kg/min.

However, VO2max cannot increase indefinitely. In his study, Hill describes a range of changes in VO2 in an athlete running on a grass track at different speeds (9). After 2.5 minutes of running at 282 m/min, his VO2 reached a value of 4,080 L/min (or 3,730 L/min above the measured resting value). Since VO2 at speeds of 259, 267, 271 and 282 m/min did not increase above the value obtained at a running speed of 243 m/min, this confirmed the assumption that at high speeds VO2 reaches a maximum (plateau), which cannot be exceeded, no matter how much it increases. running speed (Fig. 3).

Fig.3. Achieving an “equilibrium state” (plateau) for oxygen consumption at different running paces at a constant speed. The horizontal axis is the time from the start of each run, the vertical axis is oxygen consumption (l/min) exceeding the resting value. Running speeds (from bottom to top) 181, 203, 203 and 267 m/min. The lower three curves represent the true steady state, while in the upper curve the oxygen demand exceeds the measured consumption.

Today, it is generally accepted that there is a physiological upper limit to the body’s ability to consume oxygen. This was best illustrated by the classic Åstrand and Saltin plot (10) shown in Figure 4.

Fig. 4 Increase in oxygen consumption during heavy work on a bicycle ergometer over time. The arrows show the time at which the athlete stopped due to fatigue. The output power (W) for each of the jobs is also shown. The athlete can continue performing at 275 W power output for more than 8 minutes.

Speaking about the intensity of work, it is necessary to clarify one fact. Even at high intensity, blood oxygen saturation does not fall below 95% (this is 1-3% lower than that of a healthy person at rest).

This fact is used as an indication that oxygen consumption and transport from the lungs to the blood are not performance limiting factors as long as blood saturation remains high. However, some trained athletes have described a phenomenon known as “exercise-induced arterial hypoxemia” (11). This condition is characterized by a 15% drop in oxygen saturation during exercise, relative to resting levels. A 1% drop in oxygen at oxygen saturation below 95% results in a 1-2% decrease in VO2max (12).

The reason for the development of this phenomenon is as follows. The high cardiac output of a trained athlete leads to an acceleration of blood flow through the lungs, and oxygen simply does not have time to saturate the blood flowing through the lungs. As an analogy, imagine a train passing through a small town in India, where people often jump on trains as they move. At a train speed of 20 km/h, say, 30 people will be able to jump on the train, whereas at a train speed of 60 km/h, 2-3 people will jump on it at best. The train is the cardiac output, the speed of the train is the blood flow through the lungs, the passengers are the oxygen trying to get from the lungs to the blood. Thus, in some trained athletes, oxygen consumption and diffusion from the alveoli into the blood may still affect VO2max.

In addition to diffusion, cardiac output, and the number of capillaries, VO2max and blood oxygen saturation can be influenced by the breathing process itself, or more precisely by the muscles involved in the breathing process.

The so-called “oxygen price” of breathing has a significant impact on VO2max. In “ordinary” people with moderately intense physical activity About 3-5% of absorbed oxygen is spent on breathing, and at high intensity these costs increase to 10% of VO2max (13). In other words, some part of the absorbed oxygen is spent on the breathing process (the work of the respiratory muscles). In trained athletes, 15-16% of VO2max is spent on breathing during intense exercise (14). The higher cost of breathing in well-trained athletes supports the idea that oxygen demand and factors limiting performance are different between trained and untrained individuals.

Other possible reason What may limit an athlete's performance is the existing "competition" for blood flow between the respiratory muscles (mainly the diaphragm) and skeletal muscles(for example, leg muscles). Roughly speaking, the diaphragm can “pull” part of the blood onto itself, which therefore does not reach the leg muscles. Because of this competition, diaphragm fatigue can occur at intensity levels above 80% of VO2max (15). In other words, with a relatively average running intensity, the diaphragm can “get tired” and work less efficiently, which leads to the body being depleted of oxygen (since the diaphragm is responsible for inhalation, when the diaphragm is tired, its efficiency decreases, and the lungs begin to work worse).

In a review, Sheel et al showed that after inclusion of special breathing exercises, athletes showed improved performance (16). This hypothesis was confirmed by a study conducted on cyclists, where athletes developed global fatigue of the inspiratory muscles during 20 and 40 km segments (17). After training the respiratory muscles, athletes were found to have 3.8% and 4.6% improvement in 20- and 40-kilometer performance, respectively, as well as a decrease in respiratory muscle fatigue after the segments.

Thus, the respiratory muscles influence VO2max, and the degree of this influence depends on the level of training. For higher level athletes, respiratory muscle fatigue and hypoxemia (lack of oxygen) caused by physical activity will be important limiting factors.

Because of this, well-trained athletes should use breathing training, while runners entry level, most likely, will not get the same effect from it.

The most in a simple way breathing muscle training, also used in clinics, is to exhale through loosely pursed lips. You need to feel that you are exhaling with your entire diaphragm, start with slow and deep inhalation and exhalation, gradually increasing the speed of exhalation.

Oxygen transport

Since the first experiments of A.V. Hill's VO2max measurement, oxygen transport has always been considered the main limiting factor for VO2max (18).

It has been estimated that oxygen transport (this is the entire path from oxygen entering the blood to being taken up by the muscles) affects VO2max by approximately 70-75% (19). One of the important components of oxygen transport is its delivery to organs and tissues, which is also influenced by a large number of factors.

Adaptation of the cardiovascular system

Cardiac output (CO), the amount of blood pumped out by the heart per minute, is also considered an important factor limiting VO2max.

Cardiac output depends on two factors - heart rate (HR) and stroke volume (SV). Therefore, to increase maximum CO, one of these factors must be changed. Maximum heart rate does not change under the influence of endurance training, while SV in athletes increases both at rest and when performing work of any intensity. An increase in stroke volume occurs due to an increase in the size and contractility of the heart (20).

These changes in the heart cause an improvement in the ability to quickly fill the chambers of the heart. According to the Frank-Starling law, as the stretching of the heart chamber increases before contraction, the contraction itself will be stronger. For an analogy, you can imagine a strip of rubber that is being stretched. Stronger stretch - faster contraction. This means that filling the chambers of the heart in athletes will cause the heart to contract faster, which means an increase in stroke volume. In addition to this, long-distance runners have the ability to quickly fill the chambers of the heart at high intensity exercise. This is a fairly important physiological change because normally, as the heart rate increases, there is less time to fill the chambers of the heart.

Hemoglobin

Another important factor in oxygen transport is the oxygen-carrying ability of the blood. This ability depends on the mass of red blood cells, erythrocytes, as well as the concentration of hemoglobin, which serves as the main carrier of oxygen in the body.

Increasing hemoglobin should improve performance by increasing oxygen transport to the muscles. Research clearly shows this relationship by examining how lower hemoglobin levels will affect performance (21). For example, decreased hemoglobin levels in anemia lead to decreased VO2max (22).

Thus, in one study, after a decrease in hemoglobin levels, a decrease in VO2max, hematocrit and endurance was observed. However, after two weeks, VO2max was restored to baseline, but hemoglobin and endurance remained reduced (23).

The fact that VO2max can remain normal when hemoglobin levels are low raises a number of questions and demonstrates the body's extensive adaptive capabilities, reminding us that there are many ways to optimize oxygen delivery to increase VO2max. Additionally, the return of VO2max, but not endurance, to normal levels may indicate that VO2max and endurance are not synonymous.

At the other end of the spectrum are studies where hemoglobin levels were artificially increased. These studies showed an increase in both VO2max and performance (24). Eleven elite runners included in one study showed significant increases in time to exhaustion and VO2max after blood transfusion and an increase in hemoglobin levels from 157 g/L to 167 g/L (25). In a study with blood doping, which artificially increases hemoglobin, there was a 4%-9% improvement in VO2max (Gledhill 1982).

Taken together, all of the above facts indicate that hemoglobin levels have a significant impact on VO2max.

Blood volume

As hemoglobin increases, the blood becomes more viscous, since most of it contains red blood cells rather than plasma. As the number of red blood cells increases, viscosity increases and an indicator such as hematocrit increases. For an analogy, imagine how water (this is an analogue of blood with normal hemoglobin and hematocrit) and jelly (hemoglobin and hematocrit are increased) flow through pipes of the same diameter.

Hematocrit determines the ratio between red blood cells and plasma. With high blood viscosity, blood flow slows down, making it difficult and sometimes completely stopping the delivery of oxygen and nutrients to organs and tissues. The reason is that blood with high viscosity flows very “lazyly”, and may not get into the smallest vessels, capillaries, simply clogging them. Therefore, an excessively high hematocrit can potentially reduce performance by impairing the delivery of oxygen and nutrients to tissues.

During endurance training, it is normal for both blood volume and hemoglobin hematocrit to increase, with increases in blood volume up to 10% (26). In medicine, the concept of the so-called optimal hematocrit has changed quite a few times, and debates still persist about what level of this indicator is considered optimal.

Obviously, there is no clear answer to this question, and for each athlete, the hematocrit level at which there is maximum endurance and performance can be considered optimal. However, it must be remembered that a high hematocrit is not always good.

Athletes who use illegal drugs (such as erythropoietin (EPO) to artificially increase red blood cell levels) will have very good endurance and performance. The downside may be dangerously high hematocrit levels, as well as increased blood viscosity (27).

On the other hand, there are endurance athletes who run with low hematocrit and hemoglobin levels, which in normal life can be a sign of anemia. It is quite possible that such changes are a response to high-altitude adaptation of athletes.

Adaptation to high altitudes can be threefold different types (28):

• Ethiopia - maintaining a balance between blood saturation and hemoglobin
• Andes - increased red blood cell levels with decreased oxygen saturation
• Tibet - normal hemoglobin concentration with decreased blood oxygen saturation

Several adaptations suggest that there are several ways to optimize blood counts. There is still no answer to the question of which option (low or high hematocrit) has better oxygen delivery in sports. Most likely, no matter how trivial it may sound, the situation with each athlete is individual.

Another important parameter that plays a role during running is the so-called blood shunt.

This mechanism is useful when muscles need more blood and oxygen with nutrients. If at rest the skeletal muscles receive only 15-20% of the total blood volume, then during intense physical activity approximately 80-85% of the total blood volume goes to the muscles. The process is regulated by the relaxation and contraction of the arteries. In addition, during endurance training, the density of capillaries increases, through which all the necessary substances enter the blood. It has also been shown that capillary density is directly related to VO2max (29).

Oxygen utilization

Once oxygen reaches the muscles, it must be utilized. The “energy stations” of our cells - mitochondria, in which oxygen is used to produce energy - are responsible for the utilization of oxygen. How much oxygen the muscles have absorbed can be judged by the “arteriovenous difference,” that is, the difference between the oxygen content in the blood flowing (arterial) to the muscle and the oxygen content in the blood flowing (venous) from the muscle.

In other words, if 100 units of oxygen flow in and 40 units flow out, then the arteriovenous difference will be 60 units - that is how much is absorbed by the muscles.

The arteriovenous difference is not a factor limiting VO2max for a number of reasons. First, this difference is quite similar in both elite and non-elite runners (30). Secondly, if you look at the arteriovenous difference, you can see that very little oxygen remains in the vein. The oxygen content in the blood flowing to the muscles is approximately 200 ml of oxygen per 1 liter of blood, and the flowing venous blood contains only about 20-30 ml of oxygen per liter of blood (29).

Interestingly, the arteriovenous difference can improve with training, which means greater oxygen uptake into the muscles. Several studies have shown an approximately 11% increase in arteriovenous difference following systematic endurance training (31).

Considering all these facts, it can be said that although the arteriovenous difference is not the limiting factor of VO2max, important and beneficial changes in this indicator occur during endurance training, indicating greater oxygen uptake by the muscles.

Oxygen ends its long journey in the mitochondria of the cell. Mitochondria in skeletal muscle are the site of aerobic energy production. Within the mitochondria themselves, oxygen is involved in the electron transport chain, or respiratory chain. Thus, the number of mitochondria plays an important role in energy generation. In theory, the more mitochondria there are, the more oxygen can be utilized in the muscles. Studies have shown that mitochondrial enzymes increase with exercise, but the increase in VO2max is small. The role of mitochondrial enzymes is to enhance the reaction in the mitochondria to significantly increase energy production.

In one study examining changes during and after cessation of exercise, mitochondrial power increased by 30% over the course of exercise, while VO2max increased by only 19%. However, after cessation of exercise, VO2max persisted longer than mitochondrial power (32).

Conclusions:

1. The VO2max indicator characterizes the maximum amount of oxygen used.
2. VO2max is used to quantify the capacity of an aerobic system.
3. For practical purposes, measuring VO2max has little value, but developing the ability to consume and utilize oxygen more efficiently impacts a runner's performance.
4. As your running speed increases, your muscles consume oxygen at a higher rate.
5. VO2max has an end point before it reaches a plateau, or steady state.
6. The breathing process itself significantly affects VO2max.
7. The respiratory muscles influence VO2max, and the extent of this influence depends on the level of training.
8. The maximum heart rate does not change under the influence of endurance training, while stroke volume in athletes increases both at rest and during work of any intensity.
9. Hemoglobin level has a significant effect on VO2max.
10. An excessively high hematocrit can potentially reduce performance by impairing the delivery of oxygen and nutrients to tissues.

Bibliography:

1. Pollock M.L. The quantification of endurance training programs. Exerc Sport Sci Rev. 1973; 1: 155-88
2. Hawley JA. State of the art training guidelines for endurance performance. S Afr J Sports Med 1995; 2:70-12
3. Hawley JA, Myburgh KH, Noakes TD, et al. Training tech niques to improve fatigue resistance and endurance perform ance. J Sports Sci 1997; 15:325-33
4. Tabata I, Irisawa K, Kouzaki M, et al. Metabolic profile of high intensity intermittent exercises. Med Sci Sports Exerc 1997; 29: 390-5
5. A.V. Hill and H. Lupton. Muscular exercise, lactic acid, and the supply and utilization of oxygen. Q. J. Med. 16:135–171, 1923
6. R. Herbst. Der Gasstoffwechsel als Mass der korperlichen Leistungsfahigkeit. I. Mitteilung: die Bestimmung des Sauerstoffaufnahmevermogens bein Gesunden. Deut. Arch. Klin. Med. 162:33–50, 1928
7. B. Saltin and S. Strange. Maximal oxygen uptake: “old” and “new” arguments for a cardiovascular limitation. Med. Sci. Sports Exerc. 24:30–37, 1992
8. A.V. Hill, C.N.H. Long, and H. Lupton. Muscular exercise, lactic acid and the supply and utilization of oxygen: Parts VII-VIII. Proc. Roy. Soc. B 97:155–176, 1924.
9. P.O. Åstrand, and B. Saltin. Oxygen uptake during the first minutes of heavy muscular exercise. J. Appl. Physiol. 16:971–976, 1961.
10. S.K. Powers, J. Lawler, J.A. Dempsey, S. Dodd, G. Landry. Effects of incomplete pulmonary gas exchange on VO2 max. J Appl Physiol. 1989 Jun; 66(6):2491-5.
11. J.A. Dempsey, P.D. Wagner. Exercise-induced arterial hypoxemia. J Appl Physiol. 1999 Dec; 87(6): 1997-2006
12. E.A. Aaron, K.C. Seow, B.D. Johnson, J.A. Dempsey. Oxygen cost of exercise hyperpnea: implications for performance. J Appl Physiol 1992; 72: 1818–1825.
13. C.S. Harms, T.J. Wetter, S. R. McClaran, D.F. Pegelow, G. A. Nickele, W.B. Nelson, P. Hanson, J.A. Dempsey. Effects of respiratory muscle work on cardiac output and its distribution during maximal exercise. J Appl Physiol. 1998; 85:609–618.
14. B.D. Johnson, M.A. Babcock, O.E. Suman, J.A. Dempsey. Exerciseinduced diaphragmatic fatigue in healthy humans. J Physiol 1993; 460; 385-405.
15. A.W. Sheel. Respiratory muscle training in healthy individuals: physiological rationale and implication for exercise performance. Sports Med 2002; 32(9): 567-81
16. L. M. Romer, A. K. McConnell, D. A. Jones. Effects of inspiratory muscle training on time-trial performance in trained cyclists. Journal of Sports Sciences, 2002; 20: 547-562
17. D.R. Bassett Jr, E.T. Howley. Limiting factors for maximum oxygen uptake and determinants of endurance performance. Med Sci Sports Exerc. 2000 Jan; 32(1):70-84.
18. P. E. di Prampero. Factors limiting maximum performance in humans. Eur J Appl Physiol. 2003; Oct; 90(3-4): 420-9.
19. G. C. Henderson, M. A. Horning, S. L. Lehman, E. E. Wolfel, B. C. Bergman, G. A. Brooks. Pyruvate shuttling during rest and exercise before and after endurance training in men. Journal of Applied Physiology Jul 2004; 97(1): 317-325
20. J.J. Lamanca, E.M. Haymes. Effects of iron repletion on VO2mx, endurance, and blood lactate in women. Med. Sci. Sports Exerc. 1993; Vol. 25, No. 12: 1386-1392
21. B. Ekblom, A.N. Goldbarg, B. Gullbring. Response to exercise after blood loss and reinfusion. Journal of Applied Physiology. 1972; 33:175–180
22. J.A. Calbet, C. Lundby, M. Koskolou, R. Boushel. Importance of hemoglobin concentration to exercise: acute manipulations. Respira. Physiol. Neurobiol. 2006; 151:132–140
23. F.J. Buick et al. Effect of induced erythocuthemia on aerobic work capacity. Journal of Applied Physiology 1980; 48: 636-642
24. D. Costill, S. Trappe. Running: The athlete within. 2002; Traverse City, MI: Cooper Publishing Group.
25. J.A. Calbet, C. Lundby, M. Koskolou, R. Boushel. Importance of hemoglobin concentration to exercise: acute manipulations. Respir Physiol Nerubiol. 2006; 151(2-3), 132–140.
26. C.M. Beall,M.J. Decker, G.M. Brittenham, I. Kushner, A. Gebremedhin, K.P. Strohl. An Ethiopian pattern of human adaptation to high-altitude hypoxia. Proc Natl Acad Sci; 2002, 99(26), 17215–17218.
27. D.R. Bassett, E.T. Howley. Limiting factors for maximum oxygen uptake and determinants of endurance performance. Medicine and Science in Sports and Exercise. 2000; 32, 70–84
28. J.M. Hagberg, W.K. Allen, D.R. Seals, B.H. Hurley, A.A. Eshani, and J.O. Holloszy. A hemodynamic comparison of young and older endurance athletes during exercise. J. Appl. Physiol. 1985; 58:2041–2046.
29. J.H. Wilmore, P.R. Stanforth, J. Gagnon, T. Rice, S. Mandel, A.S. Leon, D.C. Rao, S. Skinner, & C. Bouchard. Cardiac output and stroke volume changes with endurance training: The heritage family study. Med Sci Sports Exerc. 2001; 22(1): 99-106.
30. J. Henriksson, J.S. Reitman. Time course of changes in human skeletal muscle succinate dehydrogenase and cytochrome oxidase activities and maximal oxygen uptake with physical activity and inactivity. Acta Physiol. Scand. 1977; 99, 91–97

VO2 max, or maximum oxygen consumption (VO2), is one of the most common measures of athlete fitness (especially cyclic species sports). What it characterizes, what it depends on and how to increase it, you will learn by reading this article.

VO2 max shows the maximum amount of oxygen the body can use in one minute and is measured in ml/min/kg. The higher this value, the more oxygen gets to your muscles, and the longer and faster you can run. VO2 max also affects cardiorespiratory endurance (this parameter determines how effectively the heart and lungs provide the body with oxygen during prolonged physical activity).

There are two main factors that affect VO2 max:

The ability of the cardiovascular system to deliver oxygen-rich blood to working muscles. High stroke volume (the amount of blood moved through the heart with each beat) and large elastic veins and arteries that can tolerate increased blood flow and a high heart rate increase VO2 max.

The body's ability to extract and metabolize oxygen for energy. Aerobic energy production occurs in structures located in muscle cells called mitochondria. A muscle that has more mitochondria can use more oxygen and therefore produce more energy. There are also a number of muscle enzymes that help process oxygen. Training aimed at developing endurance can increase both the number and size of mitochondria in the muscles and the activity of enzymes.

Heart rate and VO2 max

During physical activity, oxygen consumption increases and heart rate increases. Since these indicators are interrelated, they are often used to assess the level of cardiorespiratory endurance.

According to the American College of Sports Medicine, you can increase your VO2 max by training at 64 to 94 percent of your maximum heart rate for at least 20 minutes three times a week. It has also been found that people who have a higher BMD have a lower resting heart rate, lower blood pressure and are less susceptible to chronic disease.

How does body weight affect VO2 max?

Body mass index or BMI is a measurement that is commonly used to estimate body weight. A BMI value between 18.5 and 24.9 corresponds to normal, a figure of 25 and above indicates overweight. When a BMI exceeds 30, a person is diagnosed as obese.

According to multiple studies published in the Journal of Sports Medicine and Physical Fitness, a high BMI is often associated with a lower VO2 max. This is primarily due to changes in the respiratory capacity of the lungs and the endurance of the cardiovascular system.

A study published in the journal Chest showed a link between high BMI and poor lung function. Scientists have found that when a BMI reaches 30, functional residual capacity - the volume of air that remains in the lungs after a normal exhalation - decreases by 25 percent, and expiratory reserve volume - the additional volume a person can exhale after the end of a normal exhalation - decreases by more than 50 percent. Although these two lung measurement functions are not present during normal breathing, they limit their ability to achieve maximum efficiency and result in a decrease in VO2 max.

Standard VO2 Max Ratings

These tables list standard classifications for VO2 Max estimates by age and gender

Other Factors That Affect VO2 Max

Floor. Women have a lower VO2 max than men. This is because the latter have larger lungs and hearts, which allows them to pump more blood and consume more oxygen.

Age. Representatives of both sexes between the ages of 18 and 25 have a maximum VO2 max value, which gradually decreases as they get older. From about age 25, VO2 max declines by about 1 percent per year.

Genetics. Heredity directly influences what type of muscle fibers will predominate in your heart and what size your heart and lungs will be. Researchers at Cerritos College (California) found that genetics determines VO2 max by 20-30 percent.

Height above sea level. Low air pressure at high altitudes makes oxygen less available, and oxygen tension in the arterial blood also decreases.

Temperature. Hot air contains less oxygen, which increases the risk of hypoxia and can also affect VO2 max.

Examples of workouts to increase VO2 max

Interval running 30/30 or 60/60

This method was created by French physiologist Veronica Billat and is perfect for beginner runners and those who are in modest physical shape.

Do an easy 10-minute jog, then jog for 30 seconds at race pace or the fastest pace you can maintain for 6 minutes, then return to an easy jog. Continue alternating fast and slow 30-second stretches until you have done 12-20 reps.

A more challenging workout option involves increasing the interval time to 60 seconds.

Interval running uphill

Short uphill segments lasting 20-90 seconds are great for developing power, strength and speed, longer ones (120-180 seconds) are great for increasing VO2 max.

Before starting your workout, warm up well and run lightly for 10-15 minutes.

Then, depending on your fitness level, run uphill for 2-3 minutes. Return to the starting point with an easy, recovery run. Do 3-4 reps. Try to calculate your strength in such a way that all segments are performed at the same pace.

Interval running at the anaerobic threshold level

Running at the PANO level requires good physical shape and is recommended for advanced amateurs.

For this type of training, an athletics arena or stadium is best suited. Warm up well and run lightly for 10-15 minutes, then run 800m at race pace, and then go back to running easy (400m).

Complete a total of approximately 5000m fast run(6-7 x 800m, 5 x 1000m or 4 x 1200m).

Try to overcome all intervals with uniform intensity.

Based on materials from the site http://www.livestrong.com

The Polar fitness test is simple, fast and safe way Assess your aerobic fitness (functional state of the cardiovascular system) at rest. The result, Polar OwnIndex, corresponds to your maximum oxygen uptake (VO 2max), which is typically a measure of aerobic fitness. OwnIndex is also influenced by your training experience, heart rate, resting heart rate variability, gender, age, height and body weight. The Polar Fitness Test is intended for healthy adults.

Aerobic fitness is a measure of how well your cardiovascular system transports and uses oxygen entering the body. The better your aerobic condition, the stronger your heart and the more efficiently it works. Good aerobic fitness has a beneficial effect on overall health. For example, it reduces the risk of hypertension, cardiovascular disease and stroke. If you want to improve your aerobic fitness, on average it will take you six weeks of regular exercise to see significant changes in your OwnIndex. If you are initially in a not very good physical fitness, you will see progress even faster. The better your aerobic condition, the less your OwnIndex will change.

To improve aerobic fitness, training that involves large groups muscles. These include running, cycling, walking, rowing, swimming, skating and cross-country skiing. To track your progress, measure your OwnIndex twice during the first two weeks, and then repeat the test about once a month.

To ensure the reliability of the test results, the following basic conditions must be met:

• You can perform the test in any conditions: at home, at work, in the fitness center; however, a calm environment must be ensured. Eliminate any noise that disturbs you (TV, radio, telephone); you must not talk to anyone.
• A repeat test should be carried out under the same conditions at the same time of day.
• 2-3 hours before the test, refrain from heavy food and smoking.
• On the day of the test and the day before, refrain from excessive physical activity, alcohol and stimulant medications.
• Relax and calm down. Lie quietly for 1-3 minutes.

Before the test

Please note that the test can only be carried out if you configured the A300 device Online flow.polar.com/start .

The fitness test only works with compatible Polar heart rate sensors. Fitness Test is Polar's own smart training feature that requires accurate heart rate variability measurements. This is why a Polar heart rate sensor is necessary.

Before starting the test, check that the data you entered in the Flow online service is correct.

Carrying out the test

1. Go to the menu Fitness test > Start testing. The A300 will begin searching for your heart rate sensor. The display will show Heart rate sensor found And Lie back and relax. The test begins.
2. Lie down, remain relaxed, and limit your body movements and interactions with people. As the test progresses, the bar on the A300 will fill up.
3. When the test is completed, Test Complete appears and the test results are displayed.
4. Press the DOWN button to find out the VO 2max value. Press the START button and select Yes to update the VO 2max value displayed in the Polar Flow web service.

You can interrupt testing at any time by pressing the BACK button. The display will show Test cancelled.

Troubleshooting

• The message is displayed Touch the sensor with the A300, if the A300 cannot find the heart rate sensor. Touch the sensor with your A300 to find the sensor and pair it.
• Could not find heart rate sensor. Check that the heart rate sensor electrodes are wet and that the belt is tight enough.
• If the A300 cannot find the heart rate sensor, it will display Polar HR sensor required.

Test results

The result of the last test can be viewed in the menu Fitness test > Test results. You can also view your results in the Flow app's Training Diary.

To visually analyze the results of a fitness test, use the Flow online service, where you can view detailed information about the test from the Diary.

Fitness Level Classes

Men

Age/Years	Extremely low	Short	Satisfactory	Average	Good	Very good	Excellent
20-24	< 32	32-37	38-43	44-50	51-56	57-62	> 62
25-29	< 31	31-35	36-42	43-48	49-53	54-59	> 59
30-34	< 29	29-34	35-40	41-45	46-51	52-56	> 56
35-39	< 28	28-32	33-38	39-43	44-48	49-54	> 54
40-44	< 26	26-31	32-35	36-41	42-46	47-51	> 51
45-49	< 25	25-29	30-34	35-39	40-43	44-48	> 48
50-54	< 24	24-27	28-32	33-36	37-41	42-46	> 46
55-59	< 22	22-26	27-30	31-34	35-39	40-43	> 43
60-65	< 21	21-24	25-28	29-32	33-36	37-40	> 40

Women

Age/Years	Extremely low	Short	Satisfactory	Average	Good	Very good	Excellent
20-24	< 27	27-31	32-36	37-41	42-46	47-51	> 51
25-29	< 26	26-30	31-35	36-40	41-44	45-49	> 49
30-34	< 25	25-29	30-33	34-37	38-42	43-46	> 46
35-39	< 24	24-27	28-31	32-35	36-40	41-44	> 44
40-44	< 22	22-25	26-29	30-33	34-37	38-41	> 41
45-49	< 21	21-23	24-27	28-31	32-35	36-38	> 38
50-54	< 19	19-22	23-25	26-29	30-32	33-36	> 36
55-59	< 18	18-20	21-23	24-27	28-30	31-33	> 33
60-65	< 16	16-18	19-21	22-24	25-27	28-30	> 30

The classification is based on a review of 62 studies in which VO 2max was measured directly in healthy adults in the United States, Canada and 7 European countries. References: Shvartz E, Reibold RC. Aerobic fitness norms for males and females aged 6 to 75 years: a review. (Study of aerobic fitness standards in males and females aged from 6 to 75 years). Aviat Space Environ Med; 61:3-11, 1990.

Vo 2max

There is an established relationship between maximum oxygen uptake (VO2 max) and cardiorespiratory endurance, since the amount of oxygen delivered to tissues depends on the work of the lungs and heart. VO2 max (maximum oxygen consumption, maximum aerobic capacity) is the maximum level at which the body is able to use oxygen at maximum exercise; it is directly related to the maximum ability of the heart to supply blood to the muscles. VO2 max can be measured or calculated using fitness tests (eg, maximal exercise tests, submaximal exercise tests, Polar fitness test). VO2 max reliably reflects cardiorespiratory endurance and allows you to predict endurance during long runs, cycling rides, cross-country skiing or long distance swimming.

VO2 max can be expressed in millimeters per minute (ml/min = ml ■ min-1) or in millimeters per minute divided by weight in kilograms (ml/kg/min = ml ■ kg-1■ min-1).