PhD A.N. Korzhenevsky¹
PhD, Associate Professor G.V. Kurguzov¹
PhD V.A. Klendar¹
O.M. Mamychkin^2
1Russian Scientific Research Institute for Physical Culture and Sports, Moscow
²Ryazan Higher Airborne Command School, Ryazan

Keywords: elite boxers, middle altitude, lowland, altitude training, traditional training, precompetitive phase, competitive process, cardiovascular system, oxygen transportation indices, cycle ergometer tests, fatigue.

Background. Middle altitude oxygen-deficient trainings are ranked among the most popular physical efficiency and individual resource mobilizing methods.
Objective of the study was to analyze effects of benefits of the elite boxers’ performance control methods in customizable training conditions.
Methods and structure of the study. Sampled for the study were the 23-25 year-old elite boxers – MS, WCMS, HMS (n=9), whose body’s functional status was tested during preparation for major competitions (Championship of Russia) – in the precompetitive and competitive training periods. At the beginning and at the end of the precompetitive stage, conducted in the middle altitude conditions, the athletes’ oxygen transportation indices were recorded. At the end of this stage, and after a short rest at the beginning and in the middle of the competitive stage, held in the Moscow region, the athletes were examined using a set of methods that help obtain extensive data on their physical fitness level. Along with the study of the athletes’ biochemical indicators, we assessed the functional state of their myocardium and body in general using a cycle ergometer test.
The boxers’ physical working capacity was tested using a step load test performed on a cycle ergometer to failure. The initial load equaled 675 kgm/min, and every 2 min the load was increased by 225 kgm/min up to failure.
During the test, we recorded the subjects’ HR (every minute), and measured their blood lactate level (every second minute of each step). Changes in the HR and blood lactate level made it possible to determine the level of tension of the mechanisms of adaptation of the cardiovascular system to physical loads and aerobic and anaerobic thresholds.
The heart rate (HR) variability analysis was used to evaluate the state of the cardiovascular and autonomic nervous systems with the initial functional level, training level, degree of functional tension estimated (HF, LF, VLF, SI).
Training of boxers for the Championship of Russia was carried out in 2 stages, each characterized by an individual direction of training. In the 1st precompetitive phase, the trainings (which lasted 21 days) were carried out in the middle altitude conditions – at the height of 1240 m above sea level (Kislovodsk). The stage training process was dominated by the overall body conditioning (overall physical training - 61%, special physical training (SPT) - 39%), associated with the performance of a largest volume of aerobic loads (running, walking, general and special low-intensity loads) aimed to develop general and special endurance. Ranked second by the volume of work performed were speed-strength practices. At the same time, a specific type of activity of a mixed aerobic-anaerobic nature, similar to that performed under competitive conditions, was used only in the last 2 training micro-cycles.
The precompetitive training, which followed the middle altitude one, was conducted in the Moscow region 21 days before both the Championship of Russia and major international competitions following the championship. Immediately after the middle altitude trainings, the athletes took a rehabilitation course (rehabilitation microcycle).
In order to lead the athletes up to the competitive mode, practices with a sparring partner were used, including those using the boxing mitts and training simulators. Here, the training process was dominated by specialized high-intensity activity of a mixed aerobic-anaerobic, anaerobic alaсtate and glycolytic nature (specific loads of maximal and sub-maximal intensity from 10-20 to 30-40 sec). The volume of non-specific aerobic and speed-strength loads was reduced significantly. The process of training for the competitions was of a pronounced specialized character (SPT - 65%, overall physical training - 35%).
The hemoglobin, hematocrit, and ferritin levels were normal both in the mountains and on lowland. Consequently, trainings at this altitude do not increase the blood oxygen or physical fitness level in general.
Results and discussion. The research results showed that the middle altitude trainings do not increase the blood oxygen level. The athletes’ blood oxygen status indices (Hb, Ht, Fe) at the beginning and at the end of the precompetitive phase remained within the normal limits. However, the creatine phosphokinase level, being the marker of the muscle damage and myocardial injury, significantly exceeded the normative range [3].
Next time, the athletes were tested in the Moscow region at the beginning of the competitive stage following a short rehabilitation microcycle.
After that, the boxers’ creatine phosphokinase level decreased considerably. The HR variability analysis showed that the blood oxygen status and creatine phosphokinase indices were within the normal range when registered in the Moscow region.
The testing of physical fitness when working on the cycle ergometer revealed pronounced prevalence of the aerobic nature of energy supply during adaptation to standard loads, nonmaximum increase of HR at the peak of physical activity in the anaerobic glycolysis zone.
The significant duration of workload at the aerobic exchange threshold level, recorded on the 6th minute of testing, with longer duration of workload at the anaerobic exchange threshold level, refleced the nature of the training process associated with performance of the large endurance building loads in the middle altitude conditions.
The boxers were re-tested after the Championship of Russia when training for the major international competitions, which were also held in the Moscow region. The re-testing revealed that the hemoglobin, hemocrit, and ferritin levels were within the normative range, as in earlier studies. However, the creatine phosphokinase level increased considerably and approached the values typical for the middle altitude training conditions.
High creatine phosphokinase levels, which significantly exceeded the normative range, indicated the onset of muscle fatigue, including that of myocardial tissue.
The relative values of spectral characteristics of HR variability (HF%), associated with such an important indicator of the cardiorespiratory system functionality as maximum oxygen consumption (MOC) [2], indicated the onset of vagal hypertension.
Very high indices of respiratory waves, determining the rhythmogenicity of sinus node, indicated the tension and inconsistency of the athletes’ maximum aerobic capacity to the loads performed.
Given the pronounced correlation between the creatine phosphokinase level and HF value, it may be assumed that the middle altitude trainings lead to a considerable myocardial tension.
At this training stage, the step load test to muscular failure revealed that physical fitness (time of work), adaptation of the cardiovascular system under standard and extreme loads, blood lactate level after work did not differ significantly as compared to the earlier studies. Yet, the boxers were found to have a significant blood lactate increase when adapting to all standard loads relative to the initial testing.
The aerobic threshold was registered as early as during the 2nd minute of the cycle ergometer test, while the HR values in the boxers decreased significantly at the aerobic and anaerobic threshold level relative to the initial testing.
In both physical fitness tests, we observed a nonmaximum increase of HR at peak loading (HR did not exceed 175 bpm). This prevented us from determining the maximum reserve capacity of the body, as the work was not performed to muscular failure.
Insufficient use of high-intensity loads in the sub-maximal intensity zone at both training stages, which contributed to the ultimate mobilization of aerobic and anaerobic functions and stable physical fitness at the level of MOC, was also reflected in the adaptation to extreme cycle ergometer loads.
The athletes were unable to reveal their aerobic potential to the maximum (their HR at peak loading was nonmaximum) and the work was not performed to failure. Among the factors limiting the boxers’ physical activity at the precompetitive and competitive stages were fatigue of the neuromuscular system and myocardial tension (increased level of creatine phosphokinase and HF (%)).
There was no positive impact of middle altitude trainings on the blood oxygen status of the athletes. The athletic training of boxers in both middle altitude and lowland conditions did not affect the hemoglobin, hematocrit, ferritin levels: they did not differ significantly and remained within normal limits. There is an opinion that trainings at the altitudes from 1000 to 1500 m above sea level do not create the necessary preconditions for transferring the athletes’ body to a higher adaptation level [6].
The increase in the oxygen content is achieved at the altitudes above 1600 m [1]. At the same time, it is known that the combined effect of hypoxic factors arising in the middle altitude conditions, as well as the use of hypoxic trainings have a greater impact on the body of athletes than the high-altitude trainings [8].
The competitive activity of boxers is carried out in the sub-maximal intensity zone and places heavy demands on the maximum energy capacities. The elite boxers were found to have maximally improved aerobic and anaerobic functions during the competitive fights in the major competitions (the World Cup) (the average HR values exceeded 191 bpm., the blood lactate level after the fight was above 11 mmol/l) [4].
The indicators of functional shifts under competitive load should be used as model characteristics for evaluating the fitness level and correcting the training process of boxers.
It is the growth of the maximum aerobic capacities that forms the basis for improving the athletes’ physical qualities [5, 7].
Increased MOC contributes to the increase of aerobic metabolism of skeletal muscles and decrease in the blood lactate level, which, in turn, improves the lability of neuromuscular system and prevents fatigue.
Endurance trainings are a necessary condition for gradual preparation of the bodily functional systems for competitive activity in the sub-maximal intensity zone. During the athletic training of elite boxers, their basic endurance skills, contributing to the performance of intensive loads that increase the maximum aerobic capacity, were not developed. 
Conclusion. In order to increase the efficiency of sports training of elite boxers it is necessary to use the optimal ratio of physical loads of different orientation and intensity both at middle altitude and on lowland. Strength, speed-strength and glycolytic training loads should be performed against the background of a sufficiently high level of development of maximum aerobic capacity. It is reasonable to use the research findings when training elite boxers for the top-ranking competitions (World Championship, Olympic Games), as well as plan the training process so that athletes are in the best shape by the time of major competitions.

References

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Corresponding author: info@vniifk.ru

Abstract
Middle altitude oxygen-deficient trainings are ranked among the most popular physical efficiency and individual resource mobilizing methods. Objective of the study was to analyze effects of benefits of the elite boxers’ performance control methods in customizable training conditions. The study found the elite boxers’ altitude trainings being of no effect on the oxygen transportation efficiency of the blood circulation system; although the high-intensity endurance trainings were found to improve the aerobic energy supply mechanisms and build up the maximal energy generation capacity. Aerobic-alaсtate altitude trainings combined with the predominantly aerobic-anaerobic traditional trainings were found inefficient for the functionality building purposes, with the athletic performance efficiency limited by the neuromuscular system fatigue and stress on the cardiovascular system. The altitude and traditional trainings of elite boxers need to be designed and managed so as to effectively harmonize the varied-intensity training tools and give a special priority to sub-maximal workloads (with HR of 180+ beats per min) to improve the maximal aerobic and anaerobic capacities. Full rehabilitation days are recommended, particularly after the shock training days and competitions to effectively prevent fatigue and burnouts and improve the all-round and special boxing performance efficiency.