The aim of the study is to establish a trend in the body mass index of schoolchildren in different regions of the country. The study was carried out in 2021 as part of the all-Russian monitoring of the physical development of schoolchildren aged 7–17 years (the number of boys - 30,965, the number of girls - 33,290). The statistical software package Statistica 13 PL has been used for data processing. BMI indicators have been established for Russian schoolchildren. Some regional differences in BMI indicators and the influence of the organization of medical support factor in the region have been shown. The Pearson correlation coefficients between the BMI of schoolchildren and the availability of doctors and nurses per 10,000 of population were -0.63 and -0.39 (p ≤ 0.05). The age and gender standards for BMI for Russian schoolchildren have been updated. A trend towards higher BMI rates in various subjects of the Russian Federation has been revealed, which may be due, among other things, to indicators characterizing the organization of the medical population in the region.

The purpose of the study was to search for the relationship of Pulse Debt Accumulation Intensity (PDАI) with the rate of formation of oxygen demand and the accumulation of lactate in the blood during the performance of limiting cyclic exercises of various durations.Methods: 14 athletes‑cyclists (1st category, 20 ± 3 years, MОC — 52.9 ± 5.10 ml / min / kg), performed a series of bicycle ergometric exercises of maximum power on different days at a fixed duration of 10, 30, 60, 120, 360 and 1800 s. Based on the pulse sums of the five‑minute recovery (minus the pre‑start HR level) and the exercise time, the intensity of accumulation of pulse debt was calculated for all exercises in each subject. The rate of accumulation of lactate concentration in the blood (SNCL) and the rate of formation of oxygen demand (OCR) were also calculated.Results: SOCS, SNCL and PDАI have a close non‑linear relationship with exercise time (respectively: r2 = 0.84, r2 = 0.91, r2 = 0.96, at p < 0.05), as well as with relative exercise power (respectively: r2 = 0.80, r2 = 0.86, r2 = 0.90, at p < 0.05). INPD has a close relationship with SRCS and SNCL (respectively: r2 = 0.80, r2 = 0.94, p < 0.05).Conclusions: The results of the study make it possible to use the INPD heart rate indicator for a fairly reliable determination of exercise intensity and for predicting the level of lactate accumulation, and on this basis, determining the direction of the exercise and normalizing the training load.

Non-specific pelvic pain in young athletes can mask atypical disorders that are exceedingly rare among non-athletes. The diagnosis of this syndrome is very problematic, since it may concern different specialties, such as pediatric surgery, pediatrics, traumatology and orthopedics, neurology, gastroenterology, pediatric gynecology, etc. We report a case of lesser trochanter apophysitis in a 12-year-old female gymnast, who had been initially misdiagnosed and the disease had a mask of ischiofemoral syndrome. During the two-year diagnostic search, the athlete has undergone numerous instrumental examinations, some of them for several times (ultrasound, radiography, magnetic resonance imaging, helical computed tomography), as well as general clinical and laboratory examinations; however, many of them did not really narrow down, but expanded the range of diagnostic hypotheses. Treatment gave no positive dynamics. Laboratory and instrumental examinations performed within 2 years excluded a number of pathologies, but did not help to establish a correct diagnosis. Physical examination with the consideration of patient’s professional activity was a key method in the diagnosis of lesser trochanter apophysitis. The patient demonstrated positive dynamics in response to treatment, which confirmed the diagnosis. This case once again demonstrates possible atypical course of the diseases in young athletes and the importance of physical examination, which can significantly narrow down the diagnostic search. Key words: young athletes, pelvic pain syndrome, lesser trochanter apophysitis, ischiofemoral syndrome