A while ago we were about smart watch Withings, which learned how to measure the level of VO2 max. If you are serious about fitness, then you have probably met these concepts at some stage of your training. But what does that 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, it is great way determine the fortress of cardio-vascular system... People with high VO2 max levels have better blood circulation, which means it is more efficiently distributed to all muscles involved in physical activity.

How VO2 max is measured

This indicator consists of the number of milliliters of oxygen consumed per minute per body weight. Professional athletes take 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. The process usually takes about 10-15 minutes.

On the Withings Steel HR Sport watch, VO2 max is determined using your training speed and heart rate.

Highest VO2 max

The highest rate was recorded by cyclist Oskar Svendzen, it was 97.5 ml / kg / min. Generally, top scores are shown by representatives of those sports that require special endurance. According to statistics, rowers and runners have the highest V02 max among other athletes.

What affects the V02 max performance

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

• Gender: Typically, women have about 20% lower VO2 max than men.
• Height: The shorter a person is, the higher their performance.
• Age: The maximum level is fixed at the age of 18 to 25 years, after which it decreases.

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

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

Runners of all levels, from the avid amateur to the professional, are looking for ways to improve their workout performance to improve results and set records.

Long-distance running requires a lot of endurance training from the athlete to overcome constant physiological stress. Various ways The manipulation of physiological parameters to improve runners' endurance and performance has been underway for over 30 years, although a fair amount of questions remain (1). Most of the methods known today appeared 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 indicator of maximum oxygen consumption (VO2max) 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 so good, is it suitable for everyone and can you rely on it?

It is believed that for every jogging person, VO2max (or Daniels' VDOT) actually determines their 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've 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 do we need to pay such close attention to these numbers? In short, no.

Contrary to popular belief, VO2max is just a measurement and does not represent the fitness or potential of the athlete. In fact, it is impossible to determine the fastest among a few trained runners based on VO2max alone.

VO2max measurement does not accurately reflect the most important processes of transport and utilization of oxygen in the muscles. For a start, let's try to carefully consider this indicator, its components, as well as the effect that various stages of oxygen transport have on VO2max.

VO2max concept

The term "maximum oxygen consumption" was first described and used by Hill (5) and Herbst (6) in the 1920s (7). The main points of the VO2max theory were:

• There is an upper limit for 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 ability of the cardiovascular system to carry oxygen to the muscles.

The VO2max indicator characterizes maximum amount oxygen used, and is calculated by subtracting the amount of oxygen exhaled from the amount of oxygen taken up (8). Since VO2max is used to quantify the capacity of the aerobic system, it is influenced by a large number of factors along the long path of oxygen from the environment to the mitochondria in the muscles.

Formula for calculating VO2max:
VO2max = Q х (CaO2-CvO2),

where Q - cardiac output, CaO2 - oxygen content in arterial blood, CvO2 - 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 oxygen level in the blood flowing into the muscles (CaO2 - arterial oxygen) and the oxygen level in the blood. flowing from muscles to heart and lungs (CvO2 - oxygen content in venous blood).

Basically, the difference (CaO2-CvO2) represents the amount of oxygen taken up by the muscles. While VO2max is of little value for practical purposes, developing the ability to consume and utilize oxygen more efficiently affects a runner's performance. The uptake and utilization of oxygen, in turn, depends on a number of factors that occur along the oxygen pathway.

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

• Oxygen consumption

Air intake to 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 recovery

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

Oxygen consumption

The first step in oxygen travel is to get it into the lungs and into the bloodstream. This part is mainly responsible for our respiratory system(fig. 1).

Air enters the lungs from the mouth and nasal cavity due to the pressure difference between the lungs and the external environment (in the external environment, the oxygen pressure is greater than in the lungs, and oxygen is "sucked" into our lungs). In the lungs, air travels through the bronchi to smaller structures called bronchioles.

At the end of the bronchioles there are special formations - respiratory sacs, or alveoli. The alveoli are the place of transfer (diffusion) of oxygen from the lungs into the blood, or rather, into the capillaries that encircle the alveoli (Imagine a ball entangled in cobwebs - these will be the alveoli with capillaries). Capillaries are the smallest blood vessels in the body, their diameter is only 3-4 micrometers, this is less than the diameter of an erythrocyte. Receiving oxygen from the alveoli, the capillaries then carry it to larger vessels, which eventually flow into the heart. From the heart through the arteries, oxygen is carried 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 alveolus.

Oxygen use or demand depends on running speed. As the speed increases, more cells in the muscles of the legs become active, the muscles need more energy to maintain the pushing motion, which means that the muscles consume oxygen at a higher rate.

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

rice. 2. Dependence of VO2max and running speed. Horizontal axis - speed (km / h), vertical axis - oxygen consumption (ml / kg / min). HR is the heart rate.

The average runner reaching a speed of 15 km / h is likely to 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 rise 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 grow indefinitely. In his study, Hill describes a series of VO2 changes 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 4.080 L / min (or 3.730 L / min above his resting reading). 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 it increases running speed (fig. 3).

fig. 3. Achievement of "equilibrium state" (plateau) for oxygen consumption at different paces of running at a constant speed. The horizontal axis is the time from the start of each run, the vertical axis is the oxygen consumption (l / min) exceeding the value at rest. Running speeds (from bottom to top) 181, 203, 203 and 267 m / min. The bottom three curves represent the true equilibrium state, while the top curve shows the oxygen demand exceeds the measured consumption.

Today it is generally accepted that there is a physiological upper limit of the body's ability to consume oxygen. This has been best illustrated in the classic graph of Åstrand and Saltin (10), shown in Figure 4.

fig. 4 Increase in oxygen consumption during hard work on the bicycle ergometer over time. The arrows indicate the time at which the athlete stopped due to fatigue. The power output (W) for each job is also shown. The athlete can continue to perform work at 275 W power output for more than 8 minutes.

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

This fact is used as an indicator that the consumption and transport of oxygen from the lungs to the blood are not limiting factors of productivity, since blood saturation remains high. However, some trained athletes have described a phenomenon known as "exercise-induced arterial hypoxemia (hypoxemia - low oxygen levels in the blood, oxygen deprivation)" (11). This condition is characterized by a 15% drop in oxygen saturation during exercise, relative to the resting level. A drop in oxygen by 1% at oxygen saturation below 95% leads to a decrease in VO2max by 1-2% (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. For an analogy, imagine a train passing through a small town in India, where people often hop onto trains on the move. At a train speed of 20 km / h, say, 30 people can jump on the train, while at a train speed of 60 km / h, 2-3 people can 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 into the blood. Thus, in some trained athletes, oxygen consumption and diffusion from the alveoli into the blood can still affect the VO2max value.

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

The so-called "oxygen cost" of breathing has a significant effect on VO2max. In "ordinary" people, with moderately intense physical activity, about 3-5% of the absorbed oxygen is spent on breathing, and at high intensity these costs rise to 10% of the VO2max value (13). In other words, some part of the absorbed oxygen is spent on the breathing process (work of the respiratory muscles). Trained athletes spend 15-16% of VO2max during intense breathing exercises (14). The higher cost of breathing in well-trained athletes supports the assumption that oxygen demand and performance-limiting factors are different for trained and untrained people.

Another possible reason that the breathing process can limit the performance of an athlete 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 off” some of the blood that does not enter the leg muscles because of this. Because of this rivalry, diaphragm fatigue can occur at intensity levels above 80% of VO2max (15). In other words, with a conditionally average intensity of running, the diaphragm can "get tired" and work less efficiently, which leads to an oxygen depletion of the body (since the diaphragm is responsible for inhalation, when the diaphragm is fatigued, its effectiveness decreases, and the lungs start to work worse).

In their review, Sheel et al showed that after the inclusion of special breathing exercises in the training cycle, athletes showed an improvement in performance (16). This hypothesis was confirmed by a study carried out on cyclists, when, during 20 and 40 km intervals, athletes developed global inspiratory muscle fatigue (17). After training the respiratory muscles, athletes were found to improve performance on 20 and 40 km stretches by 3.8% and 4.6%, respectively, as well as a decrease in respiratory muscle fatigue after the stretches.

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 entry-level runners are unlikely to get the same effect.

The most in a simple way training of the respiratory muscles, which is also used in clinics, is exhalation through a loosely compressed lips. It is necessary to feel that you are exhaling with the entire diaphragm, start with slow and deep inhalation and exhalation, gradually increasing the exhalation rate.

Oxygen transport

Since the early experiments of A.V. Hill as measured by VO2max, oxygen transport has always been considered the main limiting factor for VO2max (18).

It has been calculated that oxygen transport (this is all the way from oxygen entering the blood to its absorption by the muscles) affects VO2max by about 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 ejected by the heart per minute, is also considered an important factor limiting VO2max.

Cardiac output is dependent on two factors - heart rate (HR) and stroke volume (SV). Therefore, to increase the maximum CO, one of these factors must be changed. The maximum heart rate does not change under the influence of endurance training, while the SV in athletes increases both at rest and when performing work of any intensity. An increase in SV 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. As an analogy, imagine a strip of rubber being stretched. The stronger the stretch, the faster the contraction. This means that filling the heart chambers in athletes will cause the heart to contract more quickly, which means it will lead to an increase in stroke volume. In addition to this, long-distance runners develop the ability to quickly fill the chambers of the heart at high intensity. This is a fairly important physiological change, since normally, with an increase in heart rate, there is less time left for filling the heart chambers.

Hemoglobin

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

The increase in hemoglobin should improve performance by increasing oxygen transport to the muscles. Research clearly shows this relationship by looking at how lower hemoglobin levels affect performance (21). For example, a decrease in hemoglobin levels in anemia leads to a decrease in VO2max (22).

So, in one of the studies, after a decrease in hemoglobin levels, a decrease in VO2max, hematocrit and endurance was observed. However, after two weeks, the initial VO2max value was restored, while hemoglobin and endurance remained reduced (23).

The fact that VO2max remains normal at low hemoglobin levels raises a number of questions and demonstrates the body's extensive adaptive capabilities, recalling that there are many ways to optimize oxygen delivery to increase VO2max. In addition, 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 that artificially raised hemoglobin levels. These studies have shown an increase in both VO2max and productivity (24). Eleven elite runners included in one study showed significant lengthening of time to exhaustion and VO2max after transfusion and an increase in hemoglobin from 157 g / L to 167 g / L (25). In a study with blood doping that artificially increased hemoglobin, there was a 4% -9% improvement in VO2max (Gledhill 1982).

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

Blood volume

With an increase in hemoglobin, the blood becomes more viscous, since most of it contains red blood cells, not plasma. With an increase in the number of red blood cells, the viscosity increases and an indicator such as hematocrit increases. For analogs, imagine how water flows through pipes of the same diameter (this is an analogue of blood with normal hemoglobin and hematocrit) and jelly (hemoglobin and hematocrit are increased).

Hematocrit determines the relationship 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 "lazily", and it may not get into the smallest vessels, capillaries, simply clogging them up. Consequently, too high a hematocrit can potentially reduce performance through impaired delivery of oxygen and nutrients to tissues.

In endurance training, it is normal to increase both blood volume and hematocrit with hemoglobin, and the increase in blood volume can be up to 10% (26). In medicine, the concept of the so-called optimal hematocrit has changed many times, and there is still debate about what level of this indicator should be considered optimal.

Obviously, there is no definite 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 a good thing.

Athletes who use illegal drugs (such as erythropoietin (EPO) to artificially increase red blood cell levels) will have very good endurance and performance. The flip side of the coin in this case can be a dangerously high level of hematocrit, as well as an increase in blood viscosity (27).

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

Adaptation to high mountains can be of three different types (28):

• Ethiopia - maintaining a balance between blood saturation and hemoglobin
• Andes - an increase in the level of red blood cells with a decrease in blood oxygen saturation
• Tibet - normal hemoglobin concentration with decreased blood oxygen saturation

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

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

This mechanism is useful when the muscles need more blood and oxygen with nutrients. If at rest the skeletal muscles receive only 15-20% of the total blood volume, then with 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 proven that capillary density is directly related to VO2max (29).

Oxygen recovery

Once oxygen has reached the muscles, it must be disposed of. Responsible for the utilization of oxygen are the "energy stations" of our cells - mitochondria, in which oxygen is used to produce energy. 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 oxygen units flow in, and 40 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 limiting factor for VO2max for a number of reasons. First, this difference is quite similar for both elite runners and non-professionals (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 equal to 200 ml of oxygen per 1 liter of blood, while the outflowing venous blood contains only about 20-30 ml of oxygen per liter of blood (29).

Interestingly, the arteriovenous difference score can improve with exercise, which means more oxygen uptake by the muscles. Several studies have shown an increase in arteriovenous difference of about 11% under the influence of systematic endurance training (31).

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

Oxygen ends up in the mitochondria of the cell. Skeletal muscle mitochondria are the site of aerobic energy production. In the mitochondria themselves, oxygen participates in the electron transport chain, or the 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 the amount of mitochondrial enzymes increases with exercise, but the increase in VO2max is small. The role of mitochondrial enzymes is to enhance the response in the mitochondria to dramatically increase energy production.

In one study looking at changes during and after stopping exercise, mitochondrial power increased by 30% during exercise, while VO2max increased by only 19%. However, after stopping training, VO2max remained longer than mitochondrial power (32).

Conclusions:

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

Bibliography:

1. Pollock ML. 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 maximal 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. Respir. 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

Without modern knowledge about the work and functioning of the human body at maximum loads, it is impossible for any athlete to succeed in sports, 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 state of health of any person at the moment, the capabilities of the body, and its ability to live long.

What is vo2 max exponent?

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 that the lungs and 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 mass per minute (eg ml / (kg · min)). The latter expression is often used to compare the performance of endurance athletes.

What does it characterize?

VO2max is a measure maximum speed, in which the athlete's body is able to absorb oxygen during a specific operation, adjusted for body weight.

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

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

Thus, 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 these is strong oxygen saturation transport system which includes a powerful heart, blood hemoglobin, high blood volume, high capillary density in muscles, and high mitochondrial density in muscle cells.

The second speed is the ability to contract a large number of muscle fibers at the same time, since the more muscle tissue is active at any given time, the more oxygen is consumed by the muscles.

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

The difference in indicators between ordinary people and athletes

Ordinary men aged 20-39 have VO2max on average from 31.8 to 42.5 ml / kg / min, and athletes-runners of the same age have VO2max on average up to 77 ml / kg / min.

Untrained girls and women tend to have maximum oxygen absorption 20-25% lower than 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, differences disappear in some studies. Sex-specific substantial stores of fat are thought to account for most of the metabolic differences in running between men and women.

Typically, the decrease in age-related VO2 max can be attributed to a decrease in maximum heart rate, maximum blood volume and maximum a-VO2 difference, that is, the difference between the oxygen concentration of arterial blood and venous blood.

How is Vo2 max measured?

Accurate measurement of VO 2 max includes physical effort sufficient in duration and intensity to fully load the aerobic energy system.

In general clinical and athletic testing, this typically includes a differential exercise test (either on a treadmill or on a bicycle ergometer) in which exercise intensity is gradually increased by measuring: ventilation and oxygen, and carbon dioxide concentration in inhaled and exhaled air. ...

• VO 2 max is reached when oxygen consumption remains stable despite increased workload.
• VO 2 max is correctly determined by Fick's 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 arteriovenous oxygen difference.

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

the belt speed or gradient gradually increases as the athlete achieves fatigue. The maximum oxygen consumption rate recorded in this test will be the runner's VO2max.

Calculation of VO 2 Max without a suitability test.

To determine your heart rate without a monitor, place two fingers against an artery on the side of your neck, just under your jaw. You should be able to feel your heartbeat on 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 your maximum heart rate. The most common way to calculate your maximum heart rate is by subtracting your age from 220. If you are 25, your HR max = 220 -25 = 195 beats per minute (bpm).

Let's define VO 2 max by a simple formula. The simplest formula for calculating VO 2 Max VO 2 max = 15 x (HR max / HR rest). This method counts well when compared to other general formulas.

Calculate VO 2 max. You have already determined the rest use and maximum heart rate, you can plug these values ​​into the formula and calculate the VO 2 max. Let's say you have a resting heart rate of 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 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 VO2max is to run for about six minutes in the fast pace that you can withstand during this time. So you could do a VO2max workout that consisted of a 10-minute warm-up, a 6-minute run, and a 10-minute cool-down.

But this is not the most The best way training VO2max, as you can get very tired after six minutes of effort. It is better to do slightly less effort at the same or slightly higher 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 intensity back just a little, and do slightly longer intervals.

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

Aerobic fitness (level of cardiovascular fitness) is the most important component in the process physical training... The remaining components are muscular strength and endurance, flexibility and other background functions. The level of fitness of the cardiovascular system is measured as the amount of oxygen transported by the blood pumped by the heart to the muscles and the efficiency of the muscles to use this oxygen in work. Increasing the efficiency of the cardiovascular system means empowering the heart and the entire cardiovascular system in the process of carrying out their most important task, delivering oxygen and energy to your body.

A good cardiovascular system has many health benefits. For example, the risk of cardiovascular disease, high blood pressure and diabetes and other diseases is reduced.
Cardiovascular training is most effective when large muscle groups are involved in dynamic work. These are activities such as walking, various jogging, swimming, ice skating, cycling, climbing stairs, skiing.

The heart is like any other muscle - it becomes stronger and more efficient when trained. Heart rate is a quantitative indicator of how the heart works. The healthy heart of the average person at rest beats about 60-70 times per minute. A trained heart beats much less frequently at rest and can only beat 40-50 times per minute or even less. Heart rate variability is an indicator of the quality of the heart. The lower the resting heart rate and the higher the heart rate variability, there better quality functions of the heart.

Aerobic fitness depends on age, gender, consistent exercise habits, heredity, and the overall clinical condition of the cardiovascular system. The maximum values ​​are reached between the ages of 15 and 30 and gradually decrease with increasing age. By the age of 60, the average maximum aerobic fitness is only 75% of the values ​​of 20 years of age. With a sedentary lifestyle, the decrease in the results of aerobic fitness occurs on average by 10% every 10 years, while in people leading an active lifestyle, this decrease occurs only by 5% over the same period of time.

• Maximum oxygen consumption (IPC), VO 2 max

There is a clear link between the body's oxygen consumption (VO2) and the level of cardiorespiratory (cardiopulmonary) functional fitness, because the delivery of oxygen to tissues depends on the lungs and heart function. Maximum oxygen consumption (VO2 max, VO2 max, maximum aerobic capacity) is a measure of the maximum rate at which oxygen can be used by the body during maximum work. It depends directly on the maximum performance of the heart, with which it can deliver blood to the muscles. VO2 max can be measured directly in the lab or predicted using aerobic fitness tests (maximum and submaximal tests, as well as the Polar Fitness test).

BMD is a good indicator of cardiorespiratory fitness and a good way to predict maximum performance in aerobic exercise sports such as long-distance running, cycling, skating and skiing, swimming.

The MIC value can be expressed in absolute terms as the number of milliliters of oxygen per minute (ml / min), or it can be reduced to a relative value if it is divided by body weight, i.e. as the number of milliliters of oxygen per kilogram of body weight per minute (ml / kg / min).

The relationship between the amount of oxygen consumed (VO 2) and the heart rate (HR) is linear for an individual during a dynamic load. The VO 2 max percentage can be changed to the value of the percentage of the maximum pulse (HRmax) by following formula:% HRmax = (% VO 2 max + 28.12) / 1.28.

IPC is the main component of determining the intensity physical exercise... Determination of the training target by heart rate intensity is more practical and useful, since it can be easily obtained in a non-invasive way, for example, directly online during exercise according to the readings of cardiac monitors (heart rate monitors).

• Polar Fitness Test and OwnIndex

The OwnIndex from the Polar Fitness Test represents your aerobic (cardiovascular) fitness. It predicts the athlete's maximum aerobic power, which is commonly referred to as maximum oxygen consumption (MOC) in terms of VO2 max, measured in ml / min / kg. In fact, this is an indicator of how many milliliters of oxygen your body is able to transport and use when physical work for every kilogram of weight within one minute.

The test is designed for adults with no health problems. It is fully automatic and can be done while resting in less than 5 minutes. No other equipment such as treadmill or something else is not required. This test is a simple, safe, reliable and quick way to assess your level of maximum aerobic fitness and to know your VO2 max. This is as reliable as most other submaximal training tests.
Fitness Test for calculating IPC is based on the following values:

1. resting heart rate
2. resting heart rate variability
3. age
4. self-reported level of long-term physical activity in the last 6 months

• Why conduct a fitness test at all?

The basic idea of ​​testing the level of aerobic fitness is to get information about their physical fitness and to understand what level of training a person is at. When a person receives a test result, they can compare it to the average for people of the same age and gender.
Testing motivates and inspires a person to start exercising, continue exercising or increase the physical intensity of their training. The test is most useful for tracking individual progress when comparing test results to previous values. The test shows an improvement in cardiovascular (aerobic) fitness.

The aerobic fitness test is the cornerstone of training. When an athlete knows his result, it is easier for him to choose the right heart rate range for his workouts.
In order to correctly and most accurately compare the test results, you must always carry out the test under the same conditions, at the same time, using the same heart monitor.

• How to do the test

You can take the test anytime, anywhere, but make sure you choose a convenient and quiet place where nothing will distract you. It is very important to always perform the test under similar conditions and at the same time of day.

1. Wet the transmitter for a confident reading of the signal and put it on.
2. Lie down and relax for 2-3 minutes.
3. Start the test (for RS800 / RS400: menu → Test → Fitness Test → Start, for FT80 / FT60: menu → Applications → Fitness test → Start), the current heart rate value will be displayed on the heart rate monitor screen. The test will begin as soon as the heart rate monitor can confidently read your heart rate. Lie relaxed and avoid any body movement during testing, do not raise your arms or legs, and do not speak. Place your arms along your body.
4. After about 5 minutes, the heart rate monitor will signal the end of the test and show your result: OwnIndex value and your fitness level. Click Ok.
5. The heart rate monitor will prompt you to update the VO 2 max value in your profile (Update VO 2 max?). Select Yes if you want to update your profile or No if you don't want to.

Also, in some models of heart monitors (RS800CX for example), you will be shown the calculated value of your maximum heart rate HR-max-p (HR-max-predicted) and will also be prompted to update the value of the maximum heart rate in your profile with this calculated value.

The OwnIndex value is stored in the memory of the heart rate monitor and can be viewed as values ​​and graph (on RS800 models) or as a list of results on FT60 / FT80 models.

If the test fails, your previous value will be used. The test may fail if the heart rate monitor does not receive information about every heartbeat. Every heart beat counts because it measures changes in heart rate (variability) at rest. In case of failure, the heart rate monitor will send sound signal twice and the screen displays “Test Failed”. Make sure the electrodes of the heart rate sensor are sufficiently damp and the elastic strap of the sensor is snug on your body and restart the test

The OwnIndex value affects the accuracy of the calorie consumption calculation during exercise and the operation of the Polar STAR Training Program (FT60 and FT80).

• How do you compare your results with those of other people?

OwnIndex is an estimate of the maximum oxygen consumption VO2 max in ml / min / kg. The following is a classification of BMD values ​​for men and women aged 20 to 65, broken down by age groups for which the Polar Fitness Test was developed. The classification is based on research conducted by Shvartz & Reibold in 1990. Laboratory measurements of VO 2 max were collected and processed for adults from 7 European countries, as well as Canada and the USA (Shvartz, Reibold. Standards for aerobic training for men and women aged 6 to 75 years: a review. Aviat Space Environ Med 61, 3-11, 1990).

Men: maximum oxygen consumption VO 2 max ml / min / kg

Women: maximum oxygen consumption VO 2 max ml / min / kg

General distribution:
11% of people are in grades 1-2 and 6-7
22% in grades 3 and 5
34% in class 4

This corresponds to a normal distribution (Gaussian distribution), since the classification was developed on a representative sample of people from different countries. Top athletes endurance sports typically have a VO2 max of about 70 ml / min / kg for men and 60 for women. Regularly exercising amateurs who periodically participate in various competitions have a level of 60-70 for men and 50-60 for women. Amateurs who exercise regularly, but do not participate in any competitions, have an indicator in the region of 40-60 for men and 30-50 for women, and for adults leading a sedentary lifestyle, it is most likely below 40 for men and 30 for women.

The level of proficiency shown in the table in the form of grades 1 to 7 is useful in interpreting individual results Polar Fitness Test, because cardiovascular health depends on aerobic fitness:

1. People in grades 1-3 are more likely to significantly improve their health and performance through regular exercise.
2. Those in grade 4 can at least maintain their physical fitness if they continue to exercise, but can also significantly improve their fitness and health if they increase their physical activity.
3. People in grades 5-7 are most likely already in good health and increasing training for them is aimed at increasing physical efficiency.

• What can lead to distorted test results

In order to get reliable test results, try to avoid the following points:

1. do not eat heavy food and coffee, and do not smoke 2-3 hours before the test
2. on the day of testing and the day before, do not do any particularly hard or exorbitant work
3. do not drink alcohol or any stimulants on the day of testing and the day before
4. do the test itself only when you are completely relaxed and calm, in a lying or sitting position
5. do not make any movements or talk during the test itself, coughing or just excitement can affect the result
6. the test site should be quiet and comfortable, nothing should disturb the peace and make any sounds and noises, including TV, radio and telephone

• How quickly can you see improvements in test results?

It takes a minimum of 6 weeks on average to make measurable progress in aerobic test results. Less trained people may notice progress much faster, while more active athletes may take a much longer period. On average, the change in the level of cardiovascular fitness in adults occurs by 12-15% in 10-12 weeks, if moderate-intensity training occurs 3-4 times a week for 30-40 minutes each.

The purpose of the Polar Fitness Test itself is the same as for all other level determination tests. physical fitness: control the preparation process itself. The exact OwnIndex values ​​themselves are not so much important as the general trend in these values, which allows you to correctly build your training plan to achieve your goals.

• How reliable are the OwnIndex test results?

The Polar Fitness test was originally developed from a study of 305 healthy Finnish men and women, where the prediction of VO2 max was calculated using an artificial neural network analysis. The correlation coefficient between laboratory measurements of VO 2 max and the values ​​predicted by the neural network was 0.97, and the mean prediction error of VO 2 max was 6.5%, which is very good compared to all other VO 2 max prediction tests (i.e. tests that do not directly measure BMD, as on a bicycle ergometer, but calculate it by indirect signs).

In a further development of the test, a study was performed on 119 healthy American men and women, whose results were included in the final neural network calculations, thus obtaining a total of 424 subjects. Based on these results of the artificial neural network, changes and adjustments were made to the Polar Fitness test. The test was also tested on 52 healthy men who did not belong to the group of subjects on whom the test was developed. The mean deviation of test values ​​in predicting BMD was less than 12%. The reliability and accuracy of the Polar Fitness test is considered good.

The reliability of a test is determined by how consistent and reproducible the test results are in successive trials. The reliability of the Polar Fitness test was good when 11 people repeated the test in both positions, lying and sitting, morning, lunch and evening for 8 days. The mean individual standard deviation of consecutive test results was less than 8% of the individual mean. Standard deviations were calculated separately for each time of day and turned out to be less than the average deviation of all results. This is a good indication that the test can be performed at any time of the day, but for more accurate results it is best to always do it around the same time.

• What to do if the test fails

The test will fail if your heart rate monitor cannot reliably and accurately obtain your heart rate at the beginning of the test or during the entire test process. Remember to moisten the sensor electrodes well before testing and check that the sensor elastic strap fits snugly and comfortably on your body. The heart rate monitor should be located within the transmitting range of the sensor and not be too far away, preferably not more than 1 meter, but not too close to the transmitter. Place your hands next to your body. Check the display to ensure that the heart symbol flashes regularly when starting the test.

If your model is FT40, FT60 or FT80, you will see the message “Heart rate found” at the beginning of the test. On the RS400 / RS800 models, before the test, you can start the heart monitor in the normal training mode and make sure that the heart rate readings are stable and adequate, on the RS800 model you can also turn on the display of the measurement readings R-R intervals and make sure that these readings are present, which indicates that the heart rate monitor sees the pulse clearly and well. Then you can turn off the training mode and go to the test itself.

The test was developed for adults between the ages of 20 and 65 and who do not have any medical conditions. If your heart rate is normal but the test still fails, it may be due to a heart arrhythmia. Certain types of cardiac arrhythmias can lead to abnormal heartbeat intervals, which can also lead to test discontinuation. These types of arrhythmias include atrial fibrillation, atrioventricular conduction block, and sinus arrhythmia.

However, healthy people may in some cases be susceptible to arrhythmias resulting in test failure. This situation is rare and most often associated with the fact that a person is under the influence of stress. In this case, the test should be repeated at a time when you are less stressed or when the effects of stress have passed. Sometimes taking the test in sitting position reduces arrhythmia and the test succeeds.

Translation: Max Vasiliev, 2014

Now I have the Garmin Forerunner 630, another perfect running watch, just newer and in blue. They look a little more ... masculine (620s I had white and orange). The set of functions of this watch will satisfy a runner of any level of advancement (if you don’t believe, everything is the same in the new ones, only even better) and there will probably be a few features in reserve that few people will not get to. Today, just about such.

VO2 Max, aka IPC
It was like this with me: I lived calmly and did not pay attention to the new VO2 Max value that periodically pops up on the watch screen, and it appeared approximately every time the workout was faster and more difficult than all the previous ones performed with this watch. But to determine this figure, people put on masks and run on the track. How can a watch know how it really is? Now, when I did a real ANSP and IPC test with a gas analyzer and lactate sampling, I know everything about myself. This means that the results can be compared!

“VO2 Max refers to the maximum amount of oxygen (in milliliters) per kilogram of body weight that you can absorb in a minute during maximum exercise. In other words, VO2 Max is a fitness measure that should increase as you improve. physical form”- definition from Garmin manual.

On August 27, on a test in the clinic, it turned out that my VO2 max, aka VO2 Max, is equal - in order to find out, I had to run up to a heart rate of 206 beats per minute. Garmin Forerunner 630, with which I ran about all summer, all training and two dozens of nights - and, by that time, managed to fix the number 52.

In the clinic, of course, I did not wear a watch, so the maximum heart rate that they (the watch) had to see with me was 197 beats per minute. Perhaps the fact that the VO2 max recorded by Garmin turned out to be below the real maximum is precisely due to the fact that I did not reach the maximum with it? I decided to ask Dr. Mikhail Nasekin what he thinks about all this. And Doc thinks like this:

“You paid attention to the difference in heart rate correctly: if in training you kept your heart rate at 206 beats per minute, Garmin would have written the VO2 Max value closer to the real one. But I am a supporter of making a conclusion about the correct / incorrect calculation based on statistics. Two, three or even ten observations are not enough to draw a conclusion. In practice, for most of those who accurately record all runs, the readings coincide + -2 ml / kg / min. But, I repeat, it is possible to assert that it actually exists or not after a full-fledged research. Then it will be reliable and relevant, and before that - all our fantasies. On the other hand, you will not (and no one will) do the maximum test every month. This will disrupt all training. Therefore, Garmins are indispensable for assessing the dynamics of the VO2 max. ”

So-so, dynamics, you say? Let's see what happened there with VO2 Max before and after testing in the clinic.

On July 17, I reached 52 ml / kg / min, after which for some time the indicator fluctuated between 51 and 52, and on September 25, at the satellite race of the Moscow Marathon, the clock recorded 53 ml / kg / min.

It was not possible to update the top ten record, but the watch recorded a new VO2 Max

In October, the figure changed twice (even without races) - first by 54, and then by 55. That's how the growth went! Isn't it time to get your IPC back on the gauges, Doc?

According to him, 55 for a girl of 20-29 years old is excellent, and even for a man very much. (This is me, like, bragging).

Such results are predicted by my watch. Ten and a marathon, I was already running faster!

Lactate threshold
Yes, Garmin Forerunner 630 guesses the lactate threshold. Sounds impressive, especially when the word lactate is associated with blood sampling. But clocks cannot scan blood, so in reality everything is much simpler.

The definition of the lactate threshold from the instructions looks like this:

“Lactate threshold is the intensity at which lactate (lactic acid) begins to build up in the bloodstream. When jogging, the lactate threshold indicates the level of effort. When the athlete exceeds this threshold, fatigue begins to arrive at an accelerated rate. For advanced runners, the lactate threshold corresponds to approximately 90% of your maximum heart rate at a pace between 10 km and a half marathon. For intermediate runners, the lactate threshold often corresponds to a heart rate below 90% of maximum heart rate. Knowing your lactate threshold will help you determine the intensity of your workout as well as timing your snatch in competition. ”

The watch tells the athlete two numbers - the pulse and the pace at which this threshold is reached. My Garmins decided that my heart rate was 180 and the pace was 4:29 min / km. Dr. Nasekin disagreed:

“The definition of the lactate threshold from the instructions is not bad: it describes the situation and the physiology of what happens after it is overcome quite fully. There is an inaccuracy: Garmin calculates it from the maximum heart rate, which is calculated either by the formula HR Max = 220 - age, or from the HR value Max that you set with your hands. In fact, your lactate threshold is where the ANSP is, that is, at 196 beats / min. ” Oops!

The clock has not guessed the lactate threshold. But! Firstly, they counted it from the maximum heart rate = 202, which I myself indicated once (I am already running to adjust the correct heart rate Max and see what comes of it). Secondly, my TANM turned out to be somewhat closer to the maximum heart rate (95%) than one would expect. In any case, accuracy is not as important here as the ability to follow the dynamics. : at the same pulse of the lactate threshold, the watch periodically renews the pace. It's nice when he grows up.

The clock itself
The box contains this set of the device itself, the HRM-RUN4 chest heart rate monitor and the charging cord:

Sometimes there is a complete set without HRM - you can connect any other Garmin heart rate monitor, even an older model, to the watch. But this one is the newest and most accurate. It is he who collects information about the heart rate, as well as about the length and frequency of steps, about the time of contact with the ground (each leg! It turns out to be different for the left and right), about the height of vertical oscillations (how high you jump while running. By the way, I jump as much as 8 cm!). Running statistics are mega-detailed, they can be considered and analyzed for a long time, if you understand what's what.

In the Indoor Run mode (for arenas, for the winter), GPS is disabled and the distance is determined using an accelerometer. I tried it twice, the numbers were very close to the truth.

In addition to all the data, the watch evaluates the effectiveness of the workout, gives recommendations for recovery and easily replaces the fitness bracelet: if you wear it during the day, it will count steps and periodically remind you that it is time to get up from the office chair and take the stairs, and if also do not take them off at night, they will show how much you managed to sleep. When you carry your phone somewhere in your pocket with Bluetooth turned on, the watch displays all sorts of notifications on the screen - well, there are calls or messages in Telegram. So, looking at your watch, you can decide whether to answer or it can wait until the end of the run.

A photo posted by Lena Kalashnikova (@ site) on Oct 25, 2016 at 11:03 am PDT

Forerunner 630 is not only accurate, but also fast: you just need to go outside and press the button with the runner - and the GPS is immediately captured, and the heart rate monitor is found. You don't have to stand still and wait for a signal, you can start training right away, which is especially important in cold autumn and winter. But what I value most about the Forerunner 630 is autonomy, namely wi-fi sync. What does it look like? And like this: I run home, do a hitch, and at this time the information about the run itself is sent to Garmin Connect, and at the same time to Strava and Nike +. You don't even need to do anything! I think I already wrote this ... Exactly, in.

And this is something else that is pleasant for owners of different Garmin devices: through the special Face-it application, you can put any photo on the watch's screensaver and walk around and rejoice at every glance at the screen. So that.

The cost of hours at the time of the release of the material: from 29,890 rubles. without HRM-Run4 sensor and from 33 670 rubles. bundled with HRM-Run4 at www.garmin.com

Photo: Andrey Morozov, Pyotr Tuchinsky, Marathon Photo