Maximum Oxygen Consumption (IPC) (English VO2 max - maximal oxygen consumption) is the largest amount of oxygen, expressed in milliliters, that a person is able to consume within 1 minute. It is a criterion of aerobic power. It is believed that it is the IPC that is the factor influencing and limiting performance in cyclic sports.
Methods for the indirect determination of IPC
As already indicated, a direct determination of the maximum oxygen consumption is carried out in the process of a complex and rather cumbersome experiment. The exhausting nature of the procedure for determining the IPC makes it impossible to frequently study this informative indicator of physical performance. In addition, the subjective attitude of the subject to the examination and, often, his unwillingness to perform extreme loads significantly affect the ability to accurately determine the maximum aerobic performance. In connection with the foregoing, the relevance of using methods for calculating the value of the IPC by indirect methods is understandable.
Indirect methods for measuring BMD are based on the adoption of a linear relationship between the load power, on the one hand, and heart rate or current oxygen consumption, on the other. During the dosed load, the subjects calculate the heart rate, and the BMD is obtained by extrapolating the curve of the dependence "load - heart rate". Typically, formulas or nomograms are used for this purpose.
Indirect methods of measuring the IPC are resorted to if there is no appropriate equipment for the direct measurement of the IPC, in cases when large physical exertion is contraindicated (for example, in old age), as well as in everyday practice.
The results of many studies indicate that indirect methods for measuring the IPC are quite accurate. Therefore, their use can also be resorted to when examining well-trained athletes, with the exception of those whose sports results directly depend on the state of the oxygen transport system.
Currently, the most common of the existing indirect methods for determining the maximum oxygen consumption are as follows.
The Astrand method (1960) is based on the use of nomograms. The subject performs a single load on a bicycle ergometer or by climbing a step (whose height is 40 cm for men and 33 cm for women) with a constant frequency of 22.5 lifts per minute (90 metronome beats per minute). At the 5th minute of the load, heart rate is recorded. If this is not possible, heart rate is calculated within the first 10 s of recovery from exercise. Then, according to the nomogram, the corresponding IPC value is found.
Determination of MIC according to the results of the PWC170 test. The value of PWC170 and the value of the IPC individually characterize the physical performance of a person. Between them there is a relationship close to linear (the correlation coefficient, according to different authors, is 0.7-0.9). V. L. Karpman proposed the formula:
IPC = 1.7PWC170 + 1240.
For athletes of high qualification and endurance training, this formula has the form:
IPC = 2.2PWC170 + 1070.
According to the author, the IPC values obtained by this calculation give an error not exceeding ± 15% of the IPC value obtained by the direct method. Estimated (indirect) methods are less accurate than direct methods, but they are very convenient for use in everyday practice.
How to increase the IPC
Unfortunately, modern scientists have come to the conclusion that in many respects this indicator is inherited. And the main nuisance is that you also inherit the ability to improve this indicator. But it depends on the level of oxygen consumption by the muscles, for example, how fast you can run and how long you can keep this speed. That is, your parents have already determined for you how sensitive your body is to training. And therefore, if your neighbor improved his result in a marathon by 25 minutes in a year, and you are still “sitting” in a group of four hourly marathon runners, you should not think that everything depends on the level of load and the number of kilometers per week. This may mean that your body is less susceptible to stress. You need to analyze your data and change the style of training. Numerous studies have proven that everyone reacts differently to the same loads. For some, after 5 weeks of running training for 50 minutes 4 times a week, VO2max increases by 40%, and for some it does not increase at all.
Can we improve VO2max and how to do it if nature has deprived us of talent and a strong cardiovascular system? Of course, everyone has a VO2max limit. But if you want to improve your results, if you want to run faster and longer, you need to work to improve this indicator. It may take you a little longer to reach your VO2max peak than other more successful runners, such as those born to Kenyan farmers. But putting an end to yourself, if you do not succeed, is not worth it. Progress is possible, and even in people older than 50 years.
In 2007-2008, Norwegian scientists conducted the most extensive tests of VO2max dynamics in history by the number of participants in the experiment and found that with a regular training process, any person will sooner or later achieve a good level of this indicator. Not elite, but at the level of 65-75 ml / kg / min. These studies were conducted among men and women from 20 to 90 years old (number of participants - 4631 people). The analysis of such a detailed database of the VO2 max indicator gave scientists the right to assert that, despite the limits defined by genetics, you can improve your athletic shape and even at 60 years old have this indicator higher than that of a 20-year-old young man with a sedentary lifestyle . But the best part is that the Norwegians based on these statistics have confirmed the well-known fact that a good physical shape (good VO2max level) reduces the level of risks of cardiovascular diseases, thrombosis and problems with the autonomic nervous system of the body.
Everyone can improve VO2max. Sports physiologists unanimously argue that interval training is the strongest factor in this process. Make efforts within your means, with breaks for rest. For example, 6-8 intervals of fast running for 400-800 meters with breaks for easy running or walking for 1-2 minutes. Running for 20-30 minutes is also a great workout.
But the fastest way to get fit is by running through the hills. The effort when climbing uphill not only “pumps” the pulse to the maximum size, but also puts a strain on the leg muscles. Find a pretty steep climb of 60-100 meters. Run on this hill at full speed, and “coward” down for your pleasure. If you are lucky and there is a hilly jogging route near the house, you can not only do long slow workouts on it, but also run fartleks. Run up and down the ramps at different rates, once making maximum effort on the climbs and resting on the descents, another time the other way around. You will see that “mountain” training will give a fairly quick effect and will add to you not only power, but also endurance. The famous marathon Grette Weitz regularly ran the roller coaster in the suburbs of Oslo, where she lived. She ran through the hills in winter and summer, despite the weather and icing, considering running through the hills the main training of the week.
When working on improving VO2 max, do not forget that the main thing is to recover correctly after a difficult workout. Here, mileage is less important than full recovery.
Is it possible to improve speed and endurance if, by nature, VO2 max is low and difficult to improve? Yes you can, says physiologist Matt Fitzgerald. In this case, you need to supplement the training schedules with strength exercises for the muscles of the legs and body, using this to build up the capillary network that delivers oxygen to the muscles. Work on running efficiency by devoting more time to special running exercises on running techniques. Lose weight and fat mass. Here the logic is the same as in the car. Not the fact that a car with a large engine capacity in liters will be faster than its smaller competitor. Much of the speed of a car’s acceleration depends on its weight and its efficiency, that is, on how efficiently the car uses liters of gasoline and its horsepower. By analyzing your athletic and physiological parameters, despite the genetic limits, you can achieve your ideal.
Relationship with cardiovascular disease and life expectancy
The British physiologist Archibald Hill first introduced the concept of maximum absorption of oxygen and oxygen debt in 1922. Hill and German physician Otto Meyerhof shared the 1922 Nobel Prize in Physiology or Medicine for work related to muscle metabolism. Based on these works, scientists began to measure oxygen consumption during training. Significant contributions were made by Henry Taylor at the University of Minnesota, Scandinavian scientists Pere-Olof Astrand and Bengt Saltin in the 1950s and 60s, Harvard Fatigue Research Laboratory, German universities, Copenhagen Muscle Research Center, etc.
Relationship with cardiovascular disease and life expectancy edit |Norms for different age groups
For healthy individuals, the indicator is approximately equal to 3500 ml / min. Until the age of 20, the BMD is gradually increasing, it is growing especially among young people who go to the gym. The period of 20–35 years is stabilization.
After 35 years, if there is no aerobic load, that is, there is no cardio training (such as running, rowing, biathlon), a decrease in BMD occurs in a certain period.
After 65 years, IPC in most people decreases by 1/3 of the initial youthful values.
On average, non-athletic men, VO 2 max equal to 45 ml / kg / min. In women, the value approaches 38 ml / kg / min.
What determines the value of the IPC?
Factors affecting the IPC indicator distinguish such:
- Age. After 35 years, provided there is no activity, the level of consumption is O2 rapidly declining every decade.
- IPC depends on the mass. When comparing the performance of several people. Their oxygen consumption is not compared in absolute ml / min, but in relative (9 ml / kg / min).
- Floor. Until the age of 12, there is no difference between the indicators of boys and girls. But after adolescence, young men have a higher level of maximum oxygen consumption of about 20–25% due to their greater weight, blood volume and greater cardiac output.
- The state of the cardiovascular system.
The maximum oxygen consumption does not depend on the amount of food, on the number of workouts per day or on the time of day of the workout. It is more important for the runner not to gain weight, to remain light.
Maximum oxygen consumption is a value that is pretty hard to control. In many ways, the IPC indicator determines heredity. It happens that even the maximum efforts, diets are not enough to go into a big sport, if the heart is not so strong by nature.
Option No. 1. Determination of the microprocessor-based method according to the Astrand method.
For work you need: a bicycle ergometer, steps 40 cm and 33 cm high, a metronome, a stopwatch, an Astrand nomogram. Progress: on the bicycle ergometer, the subject performs a 5-minute load of a certain power. The load value is selected so that the heart rate at the end of the work reaches 140-160 beats / min (approximately 1000-1200 kgm / min). The pulse is counted at the end of the 5th minute for 10 seconds. by palpation, auscultation or electrocardiographic method. Then, the magnitude of the IPC is determined by the Astrand nomogram, for which, by connecting the heart rate line during the load (the scale on the left) and the body weight of the subject (the scale on the right), the value of the IPC is found at the point of intersection with the central scale.
Option number 2. Determination of IPC by step test.
Students perform the test in pairs. The test subject ascends a step 40 cm high for men and 33 cm for women at a speed of 25.5 cycles, in 1 minute, within 5 minutes. The metronome is set to a frequency of 90. At the end of the 5th minute for 10 seconds. heart rate is recorded. The value of the IPC is determined by the Astrand nomogram and is compared with the standard with sports specialization (Table 9). Given that the IPC depends on body weight, calculate the relative value of the IPC (IPC / weight) and compare with average data, write a conclusion and give recommendations.
How to increase the IPC?
There are 3 methods known as purely mechanically possible to increase the IPC:
- Stretch the heart, increasing blood flow.
- Through exercise and nutrition, increase hemoglobin levels. If there are more transport cells for oxygen, more energy will be released by mitochondria.
- The third way is training your leg muscles. When the muscles and vessels of the legs and arms are kept in good shape, the bloodstream has no obstacles in the way.
For the athlete, the IPC level is the limit of the “energy production" possibilities. When there is not enough oxygen, energy is generated by hydrogen. And the heart has to work more often to remove metabolic products from the body.
Value for athletes
Athletes have the maximum oxygen consumption - this is the main indicator of their "suitability" to the world of professional big sport. For long-distance runners, skiers and rowers, the MPC level exceeds 80 ml / min, and sometimes 90 ml / min.
To maintain their body, they must adhere to special diets and sleep at night for the required number of hours to restore energy consumption. They are completely forbidden to drink alcohol. Bad habits disrupt hemodynamics, and muscle tone decreases.
Aging processes. How to slow down?
It is known that every 10 years, the IPC indicator is reduced by 10%. Reduced aerobic ability reduces activity and stamina. This becomes especially noticeable after 40–45 years. It becomes more difficult for a person to perform physical physical activities. In physiology, therefore, consider the maximum oxygen consumption as a marker of aging. Take it into account together with other important indicators.
Moreover, this indicator has been used for a long time. Biological age is not always exactly equal to the real, passport. The body is much more worn out by someone who does not play sports and abuses bad habits, such as smoking. And even at 40 such people can look at 55. And their joints and blood vessels will be much “older” than they should be.
But constant exercises, jogging can delay the aging process, such as reducing the elasticity of blood vessels, increasing pressure and aging of cells. Special studies have shown that runners in old age are less likely to get cancer or die from a heart attack.
While a seasoned athlete, constantly experiencing aerobic exercise, at 40 will look younger and feel more healthy and cheerful.
Definition of IPC
The maximum oxygen consumption is determined in most cases by an indirect method. The direct method is to bring the athlete to extreme exhaustion when the rhythm of his heart is at the limit of its permissible limits.
With the indirect method, the indicator is calculated using formulas after 5 minutes of running on a treadmill. The most famous methods are: Astrand nomogram, Cooper test.
According to the Astrand nomogram, the test is carried out as follows. In the last seconds of the fifth minute of active exercises, the participant in the experiment checks the heart rate. Before that, its exact weight is measured. Lines are then drawn on the graphic scale. And at the intersection of two graphs, the average value of the IPC is determined.This is a simple test and it does not do any harm to the athlete.
The maximum oxygen consumption characterizes the functional state of the respiratory and cardiac systems. The indicator can be used to select athletes for special competitions, but they also sometimes use the IPC to diagnose how much the body has worn out, that is, grown old.
There are 2 ways to determine the IPC - the direct method and the indirect method. Most often, they use the indirect method, which is safer for health.
Option No. 3. Determination of IPC by pwc170 value.
Progress: calculation of the IPC is performed using the formulas proposed by V. L. Karpman:
IPC = 2.2 PWC170 + 1240
- for athletes specializing in high-speed power sports,
IPC = 2.2 PWC170 + 1070
- for endurance athletes. Execution algorithm: determine the value of the IPC according to one of the options and compare it with the data in accordance with the sports specialization according to the table. 9, write a conclusion and give recommendations.
Option number 4. Determination of performance by the Cooper test
Cooper test consists in running the maximum possible distance on flat terrain (stadium) in 12 minutes. If signs of fatigue occur (shortness of breath, tachyarrhythmia, dizziness, heart pain, etc.), the test stops. The test results correspond to the value of the IPC determined on the treadmill. The Cooper test can be used in the selection of students in the section on cyclic sports, during training to assess the state of fitness.