Effect of muscle electrical stimulation on electrophysiological parameters of cardiac work in athletes.

During the period encompassing 10 sessions of the quadriceps femoris muscle electromyostimulation in athletes (n=72), the following cardiac parameters changed significantly: QT-interval dispersion and the incidence of supraventricular and ventricular extrasystoles decreased, while the circadian index increased. No significant changes in the temporal- and frequency-domain parameters of the heart rate were observed, although there was a clear trend to normalization of the disturbed sympathovagal balance in the athletes.

New aspects of the influence of quadriceps femoris muscle stimulation course on functional capabilities of the organism.

We studied the effect of a course of electrical stimulation of the quadriceps femoris muscle with submaximal contraction under biofeedback conditions on functional capabilities of the organism. In addition to the known effects, electrostimulation course modulated the content of intra- and extracellular fluid and increases MDA content and creatine phosphokinase activity, which can be a manifestation of overtreatment. Impairment of body static balance after the course was revealed.

Cross effect of electrostimulation of quadriceps femoris muscle during maximum voluntary contraction under conditions of biofeedback.

We describe cross effect of enhancement of muscular power and electrical activity during electrical stimulation. Due to the use of electrostimulation method with biological feedback and effort visualization for the examinee, its expression on non-stimulated leg by some indices approached that on the stimulated leg.

Assessment of biochemical characteristics of the saliva using Fourier transform mid-infrared spectroscopy.

We developed a method of rapid assay for biochemical properties of the saliva based on attenuated total reflection infrared spectroscopy. This method allows evaluating saliva composition within 5 min without sample preparation; 10 microl sample is enough for the analysis. The concentration of total protein, glucose, secretory immunoglobulin A, urea, amylase, cortisol, inorganic phosphate in the saliva can also be measured.

Effect of a six-hour marathon ultra-race on the levels of IL-6, LIF, and SCF.

The effects of 6-h marathon ultra-race (long aerobic work below the lactate threshold level) on the levels of IL-6, leukemia inhibiting factor (LIF), and stem cell growth factor (SCF) were studied. The athletes participating in the study had different endurance levels evaluated by the distance covered over 6 h. The level of IL-6 sharply increased after exercise.

Changed profile of splicing regulator genes expression in response to exercise.

Intensive exercise triggers the cascade processes of body adaptation, including modulation of splisosome functioning, and can lead to modification of its activity and choice of alternative exons. We studied the effect of exercise of the maximum aerobic power on activation of transcription of genes involved in the splicing process. Short-term exercise resulted in a significant increase of mRNA expression of genes encoding proteins involved in the formation of precatalytic splisosome: DDX17, DDX46, HNRNPR, PRPF4B, and SRPK2.

PPARG Gene polymorphism and locomotor activity in humans.

The distribution of PPARG gene allele frequencies (Pro/Ala polymorphism) was studied in sportsmen specialized in speed and force athletics. A relationship between genotypes and human muscle transverse section area was evaluated. The PPARG Ala allele was significantly more incident in athletes than in controls, the incidence increasing with higher athletic qualification.

Free testosterone as marker of adaptation to medium-intensive exercise.

A 4-week study of adaptation reserves of the body was carried out during medium intensive exercise (medium intensive training: 60-80% threshold anaerobic metabolism). Two groups of athletes were singled out by the results of pulsometry analysis: with less than 20% work duration at the level above the 80% threshold anaerobic metabolism and with more than 20% work duration at the level above 80% threshold anaerobic metabolism. No appreciable differences between the concentrations of total testosterone, growth hormone, and cortisol before and after exercise in the groups with different percentage of anaerobic work duration were detected.