[Optimization of training: development of a new partial load mode of strength training].

Hypertrophic effect of strength training is known to originate from mechanical and metabolic stimuli. During exercise with restricted blood supply ofworking muscles, that is under conditions of intensified metabolic shifts, training effect may be achieved with much lower external loads (20% of one repetition maximum (1 RM)). The aim of the study was to compare the effects of 8 wks high-intensity (80-85% MVC) strength training and low-intensity (50% 1 RM) training without relaxation. The high-intensity strength training leads to somewhat higher increments in strength and size of trained muscles than training without relaxation. During high-intensity training an increase of area occupied by type II fibers at muscle cross section prevails while during training without relaxation - an increase of area occupied by type I fibers takes place. An exercise session without relaxation leads to a more pronounced increase in secretion of growth hormone, IGF-1 and cortisol. Expression of gene regulating myogenesis (Myostatin) is changed in different ways after high-intensity strength exercise session and after exercise session without relaxation. Low-intensity strength training (50% 1 RM) without relaxation is an effective way for inducing increases of strength and size of trained muscles. This low intensive type of training may be used in restorative medicine, sports and physical culture.

[Final blood lactate concentration after incremental test and aerobic performance].

The aim of the study was to check the hypothesis that elite endurance athletes (junior and national team) show the decreased final blood lactate concentration after incremental test till exhaustion with increased aerobic performance level. 20 physical active men and 45 elite middle and long distance endurance athletes (speed skaters, triathletes, cross country skiers) participated in the study. Significant negative correlations (r = -0.59--0.87) were found between final blood lactate concentration after incremental test till exhaustion and aerobic performance (anaerobic threshold (AT)) for athletes groups and not for physically active subjects. Moreover the less final blood lactate concentration and more VO2 at AT have elite speed skates, the higher volume of type I muscle fibers in working muscle they have (r = -0.84 and r = 0.7, accordingly).

[Physiological effects of using the low intensity strength training without relaxation in single-joint and multi-joint movements].

The effects of classical strength training (CT) and low intensity strength training without relaxation (TwR) upon size, strength and fatigability of leg muscles in men were compared. A 8-10-week strength training led to an increase of size and maximal voluntary contraction of trained muscles. After the CT, the increment of strength was higher; on the other hand, strength increments related to total work performed increased after the TwR noticeably higher than after the CT. Two training programs influenced the size of total muscle and of muscle fibers (MF) differently: the volume of m. quadriceps femoris increased more after the CT than after the TwR. The CT induced a significant increase of cross sectional area (CSA) of fast MF, and the TwR induced an increase of CSA of slow MF. Resistance to fatigue after the TwR was higher than after the. The effects of TwR were more pronounced in single-joint movements training than in multi-joint movement.

[The association of gene polymorphisms with the muscle fiber type composition].

Muscle fiber composition of m. vastus lateralis has significant individual variability mainly depending on genetic factors. Present study shows analysis of association between polymorphisms of three muscle performance-related genes and muscle fiber type composition in 48 young healthy men. DNA was obtained from mouthwash samples by alkaline extraction. Polymorphism determination of PPARalpha, ACE and ACTN3 genes was performed using polymerase chain raction. Muscle fiber typing from m. vastus lateralis was performed using immunohistochemistry method. We found an association of increased frequency of intron 7 G allele of PPARalpha gene (93.9% vs 60.0%) and D allele of ACE gene (68.8% vs 34.4%) in the group with the highest proportion of slow-twitch fibers (56-70%) compared to the group with the lowest proportion (25-43%). Thus, PPARalpha and ACE genes can be considered as potential candidate genes for muscle fiber type determination.

[Phenotypic and genetic analysis of a variant of human immunodeficiency virus (HIV-1) subtype B, isolated in Russia]. / Fenotipicheskii i geneticheskii analiz varianta virusa immunodefitsita cheloveka (VICh-1) subtipa B, vydelennogo v Rossii.

Human immunodeficiency type 1 virus env subtype B 95RU25B isolated from a Russian citizen is studied. The time course of clinical changes and immunological parameters over 5.5 years is presented. Phenotypical characteristics of the isolate were assessed by culturing in different sensitive cell cultures. Genotyping by the heteroduplex analysis and env gene sequencing were carried out. 95RU25B variant is capable of infecting a wide spectrum of cell cultures and by the type of replication can be classified with the S/L.3 group. The phenotypical properties of the isolate apparently determine the characteristic features in the primary structure of V3 loop.