[Rates of breathing values and kinetics of respiration response in critical patterns of muscular activity in middle and long distance running].

Parameters of ventilation influx, ventilation debt and ventilation demand of exercise were calculated on the basis of heart rate dynamics and parameters of external breathing during the testing procedure and recovery of elite runners during of the maximum workout. It was established that all of external breathing values closely reproduce changes of basic parameters of oxygen demand during the exercises at high intensity and duration and can be used for quantification and valuation of exercise loads in sport. During the conducted at the research it was experimentally proved that high level of sporting achievements in middle and long distance running is defined by three major factors of an aerobic exchange in an organism: 1. General ratio of increase in level of pulmonary ventilation (VE), consumption of oxygen (VO2) and allocation of carbon dioxide (CO2); 2. During the expiration--rate and of supply speed of oxygen (O2) from lungs to working muscles; 3. Rate of oxygenation (StO2) and total speed of the blood-groove.

[Metabolic states at athletes in the strenuous muscular activity of variable character].

Investigated dynamics of metabolic conditions at athletes in strenuous muscular activity of variable character. The sportsmen of high qualification specializing in bicycle and skating sports, performed in vitro work on a bicycle ergometer at level of critical power at the maximum consumption of oxygen. In two additional series of experiences each of examinees has performed work on critical power by the initial accelerations making 28% from limiting duration of exercise of 45 and 108 seconds. At work on critical power on a course of performance of exercise consecutive change of metabolic conditions with a phase initial a log-period, fast exponential increase to level of the critical power, the subsequent maintenance of critical power and final dissociation of functions of an aerobic metabolism at increase of local exhaustion was traced. It is established that the most effective concerning work maintenance at level of critical power are short-term (no more than 10 s) initial accelerations on the power corresponding to 45-second limiting exercises: these accelerations stimulate development of functions of an aerobic metabolism and don't lead to exhaustion anaerobic resources and to development of the expressed local exhaustion in the end of work.

[Age-related changes of somatotype and body mass components in girls].

The longitudinal and transverse studies of girls aged 7 to 17 years living in Moscow and the town of Yelabuga were performed to monitor the dynamics of their growth processes, parameters of ectomorphism, mesomorphism and endomorphism depending on the type of body build. Anthropometric, anthroposcopic metods and cluster analysis were used to evaluate the type of body build according to V.G. Shtefko and A.G. Ostrovskiy (1928). Quantitative assessment of parameters of endo-, meso- and ectomorphism was performed using Heath-Carter method (1980). It was shown that the age-related variability of the types of body build appeared in association with the developmental heterochronism, which resulted from the uneven growth rate of different body components. The least variable parameters were found in the girls of digestive and asthenoid types of body build, while in girls of muscular and thoracic types these parameters changed more frequently. The critical periods during which the significant changes of somatotype were increased in number, were defined as 9 to 10 years and puberty period--11 to 14 years. Most sensitive time points in the time-course of somatotype establishment in girls are the ages of 12 and 14 years.

[Changes of body mass components and body constitution in boys 7-17 years of age]. / Izmenenie komponentov massy tela i teloslozheniia u mal'chikov 7-17 let.

The longitudinal studies of boys aged 7-17 years were performed to trace the dynamics of growth processes, indices of endomorphism, mesomorphism and ectomorphism according to type of body build. The indices of somatotype stability, proposed by the authors, depending on the age and body build, are discussed. It is shown that the least variable are the boys of asthenoid and digestive types of body build, while those belonging to muscular and thoraco-muscular types undergo changes most frequently. At the age of 9-10 years the somatotype variability is the greatest. By the age of 15-17 years the proportion of the boys belonging to asthenoid-thoracal type is increased, that is characterized by a deceleration of skeletal muscles development and an increase in the ectomorphism index.

[Age and constitutional features in the forming of posture in children 7 to 14 years of age]. / Vozrastnye i konstitutsional'nye osobennosti formirovaniia osanki u detei ot 7 do 14 let.

Longitudinal study of forming of the posture was performed in 138 healthy pupils of Moscow school No. 710 aged from 6.5 to 14 of both sexes. Simultaneously children were examined anthropometrically and their constitution was determined after Schtefko. The posture was examined visually. It was established that posture forms within observation terms depending on sex, age and somatotype. Peak age for the risk of posture disturbance is 9-11 for girls and 10-12 for boys. Digestive and muscular somatotypes provide favourable prognosis respective to posture (in girls), while astenoid somatotype is the worst. Special type of posture defect is characteristic for each somatotype. In children with digestive and muscular somatotype primary posture defects disappear by 12-14. In children with astenoid and thoracal somatotype their number, in contrary, grows.

[Formation of individual somatotype parameters and features of constitutional organization in 7-12-year-old boys (longitudinal)]. / Stanovlenie individual'nykh pokazatelei somatotipa i osobennostei konstitutsional'noi organizatsii u mal'chikov 7-12 let (longitudinal'nye issledovaniia).

Individual somatotype parameters and peculiarities of constitution in 7-12 years boys were evaluated in the present investigation. The age range studied was shown to be divided on 3 stages. Regular growth processes with the prevalence of "infantal" proportions occur at the age of 7-9. Signs of definite constitutional type are expressed yet insufficiently. The age of 10-11 is transitional which shows in delay of muscle growth. At the age of 11-12 prepubescent sets in, during which features of constitution types and appropriate somatotype parameters are distinctly manifested.

[Changes in the succinate dehydrogenase activity in the muscle fibers of the m. quadriceps femoris of boys 7 to 17]. / Izmenenie aktivnosti suktsinatdegidrogenazy v myshechnykh voloknakh chetyrekhglavoi myshtsy bedra u mal'chikov 7--17 let.

Different gradations of m. quadriceps femoris muscular fibres were revealed by means of histochemical method of succinate dehydrogenase activity determination in boys from 7 to 17-years old. Energetic profile of different types muscular fibres was shown to change unevenly in postnatal ontogenesis. Most muscular fibres tend to reduce oxidation activity by the age of 17. This proves the standing that muscular fibres are not stable structures and their energetic profile is dependent on the hormonal background of a growing organism.

[Age-related changes in the weight of the body and of the extremity muscles in boys 7 to 17 years old]. / Vozrastnye izmeneniia massy tela i myshts konechnostei u mal'chikov 7--17 let.

Mass-inertial characteristics of upper and lower limbs determined in boys aged from 7 to 17 by anthropometric method. It was shown that body weight and weight of muscles of upper and lower limbs continuously increased. Dynamics of muscle groups studied changed unevenly in ontogenesis. Phases of slow (from 7 to 11 years) and fast (from 12 to 17) growth can be distinguished. Muscles of upper and lower limbs synchronously increase between 8 and 9 years of age, the parameters of the growth speed being twice as higher for arms than for legs. At 10 years growth processes reduce. In puberty musculature growth speed begins to increase between 11 and 12 years. Only speed of arm muscles growth increased at that time, while growth processes of lower extremities start to accelerate at 12-13 years. It was demonstrated that muscles growth in puberty occurs in two stages. Periods of arm muscles growth are 12 and 15 years and that is 13 and 15 years for leg muscles. Most significant growth speed for both groups falls on the age of 15. By 16 years growth speed reduces both for body and limb muscles weight. However, by 17 years growth speed increase for body weight and leg muscles only.

[Histochemical characteristics of the muscle fibers of the biceps and triceps brachii muscles in human ontogeny]. / Gistokhimicheskaia kharakteristika myshechnykh volokon dvuglavoi i trekhglavoi myshts plecha v ontogeneze cheloveka.

By means of morphometrical and histochemical methods for revealing myosin ATPase and SDG activity development of various types of muscle fibers (MF) has been studied in the postmortem material, using m. biceps and m. triceps brachii in human ontogenesis. The flexors and extensors have features in common in the dynamics of the MF maturation, and some distinctive peculiarities. The appearance of histochemical distinctions between the MF takes place on the 5th-6th months of the intrauterine development. Morphofunctional specialization begins with formation of tonic fibers. During the 1st-2nd years phasic fibers form. A relative amount of fast MF in both muscles increases at the age of 11-12 years. The dynamics of final specialization of the MF is connected with stages of sexual maturation. The first stage of the sexual maturation (about 14 years of age) is connected with decrease in the relative amount of the MF of glycolytic type of energy supply and corresponding increase in the number of oxidative type structures. From 15-17 years of age a final differentiation begins, it is connected with an intensive transversal growth of all the MF and distinguish of thick glycolytic MF. The m. biceps brachii has a relatively greater amount of oxidative fibers, and the m. triceps brachii, glycolytic ones. The transversal section area of the MF in the m. triceps brachii exceeds that of the m. biceps brachii, beginning from the 7th month of the intrauterine development up to 14 years of age. The investigation performed does not reveal any anticipating development either in the flexors or in the extensors. The differentiating processes in the m. biceps and m. triceps brachii occur nearly simultaneously.

[Development of different types of muscle fiber in the postnatal ontogeny of guinea pigs]. / Razvitie myshechnykh volokon raznogo tipa v postnatal'nom ontogeneze morskoi svinki.

As demonstrates estimation of myosin ATPase and SDG activity, the guinea pig is already born with differentiated muscle fibers (MF), and the first histochemical differences between them take place in the uterine 10 days before birth. Tonic oxidative fibers of the first type, arranging hexagonally, develop especially quickly at early stages of postnatal ontogenesis. Their relative contents up to the end of the observations (185 days) do not change, and area of their transversal section increases but slightly in comparison to the phasic fibers. The main age changes of the muscle tissue are connected with formation and rearrangement of the phasic fibers. The most intensive reconstructions of the phasic fibers coincide with the period of game activity and sex maturation. In mixed muscles the part of the glycolytic fibers increase during the postnatal ontogenesis. In the process of ontogenesis the soleus muscle fully consists of oxidative fibers. The definitive level of the MF development is established after the guinea pigs have reached their sex maturation. Comparing the results of the given investigation with the previous data on development of MF in rats, it is possible to conclude that term and premature animals have various rates in development of the muscle system, however, main stages of myogenesis coincide, though they are connected with various phases of ontogenesis.

[Development of various types of muscle fibers in the quadriceps femoris and the soleus during human ontogenesis]. / Razvitie razlichnykh tipov myshechnykh volokon chetyrekhglavoi myshtsy bedra i kambalovidnoi myshtsy v ontogeneze cheloveka.

By means of histological methods for revealing adenosine triphosphatase of myosin (pH 4.6) and succinate dehydrogenase activity, using postmortem material, development of various muscle fibers of the femoral m. quadriceps and m. soleus has been studied in human ontogenesis. The first stage of rearrangements lasts from the 5th-6th month of the uterine development up to 2 years of age and is characterized by formation (from non-differentiated) of oxidative, glycolytic and oxidative-glycolytic fibers. During the period from 2 up to 7-8 years of age the ratio in the types changes slightly, but transversal section size of the muscle fiber increases intensively. Then from 11 up to 17 years of age, together with maximal increment of the fibers transversal section, there is an essential change in the type relation. By the 17th years of age, in the femoral m. quadriceps the part of the fibers with glycolytic type of energy supply increases, while in the m. soleus the oxidative fibers become more numerous. By the 70th years of age in the femoral m. quadriceps relative amount of intermediate fibers increases.

[Growth of different types of muscle fibers of the soleus muscle during postnatal ontogeny in the rat]. / Razvitie razlichnykh tipov myshechnykh volokon kambalovidnoi myshtsy v postnatal'nom ontogeneze krysy.

In order to study the development of the m. soleus muscle fibers during postnatal ontogenesis in the rat, methods for revealing ATPase activity of myosin at preincubation in acidic and alcaline medium and lactate dehydrogenase and succinate dehydrogenase activity have been used. The m. soleus undergoes three stages of development. The first stage--from birth of the animal up to the 7th day. During this time the muscle is homogenous. The second stage is characterized by appearance of certain histochemical differences in the muscle fibers. The muscle becomes mixed. During the whole period (in males from the 7th up to the 175th, and in females from the 7th up to the 60th-70th day) transferring of glycolytic fibers into oxidative-glycolytic ones with their successive transformation into oxidative fibers is observed. During the third stage (in males older than 175, and in females older than 60-70 days) the m. soleus converts from the mixed into the homogenous one consisting of oxidative fibers.