The aim of the study was to assess the within-subject (day-to-day) variability for iron status variables: ferritin (ferr) and soluble transferrin receptor (sTfR) concentrations in plasma and the sTfR/log ferr index in athletes subjected daily to high physical loads. Blood was sampled in the morning from 8 healthy male elite judoists, aged 20 - 31 years, for 10 consecutive days while at training camp. Mean concentrations of ferritin and sTfR in plasma for the 10 day period were 32.0. 1.771(+/-1) and 2.41. 1.324(+/-1) mg/l, respectively. The average within-subject, day-to-day variability for ferritin was 27.4 % (range: 16 - 44 %), and was much lower for sTfR (6.7 %; range: 4 - 15 %). Ferritin concentrations were significantly, albeit weakly, correlated with training loads on the preceding day (r = 0.256; p < 0.05) and with creatine kinase (CK) activities on the same day (r = 0.397; p < 0.001), while sTfR did not correlate with either training loads or CK activities. Mean day-to-day variability for the sTfR/log ferr index was 11.8 % (range: 5 - 21 %), i.e. markedly lower than for ferritin. Although the physical load-induced changes in iron metabolism indices in male subjects were similarly oriented as in the earlier reported female ones representing the same sport, the magnitude of those changes was less pronounced than in the females. This was evidenced by a markedly lower within-subject day-to-day variability in ferritin, still significant but weak correlation between load magnitude and ferritin levels, and a significant, negative correlation between ferritin and sTfR concentrations, not found previously in the female athletes. However, despite lower variability in ferritin than in women, the exercise-induced ferritin increases in male athletes might make a reliable assessment of iron stores in them difficult. The present results confirm our earlier reports that sTfR levels are stable under high physical loads, thus making them a useful indicator of iron status. Also sTfR/log ferr index is of a much higher diagnostic value than ferritin, despite high variability of the latter. That index is particularly valuable in detecting iron-deficient erythropoiesis.

Background: The present study assesses the frequency of injury in Europe’s top-level judokas, during top-level competitions, and defines risk factors. Methods: The members of the EJU Medical Commission collected injury data over the period of 2005 to 2020 using the EJU Injury Registration Form at Europe’s top judoka tournaments. Results: Over the 15 years of the study, 128 top-level competitions with 28,297 competitors were included; 699 injuries were registered. Of all competitors, 2.5% needed medical treatment. The knee (17.4%), shoulder (15.7%), and elbow (14.2%) were the most common anatomical locations of injury. Sprains (42.2%) were by far the most frequent injury type, followed by contusions (23.1%). Of all contestants, 0.48% suffered an injury which needed transportation to hospital. There was a statistically significant higher frequency of elbow injuries in female athletes (p < 0.01). Heavy-weight judokas suffered a remarkably low number of elbow injuries, with more knee and shoulder injuries. Light-weight judokas were more prone to elbow injuries. Conclusions: We found there was a low injury rate in top-level competitors, with a greater frequency of elbow injuries in female judokas. During the 15 years of injury collection data, an injury incidence of 2.5% was found, with a remarkable high injury rate in the women’s −52 kg category, and statistically significantly more elbow injuries in women overall.

We concluded that the increases in NMIs highlighted functional changes in the interplay between core and shoulder muscles during an endurance contraction in elite judokas.

The basis for achieving success in sport is technical preparation supported by adequate level of physical fitness. During judo competitions, athletes use technique to meet tactical objectives aimed to achieve victory. The modification of the rules of combat in judo that has been carried out in recent years has changed the course of competition. It seems to be interesting if there are relations between technical and tactical preparation expressed by means of indices and modification of the course of the fight caused by changes in the rules. The purpose of the paper was to determine the values of technical and tactical preparation of judokas during competition at the elite level. A hundred and twenty bouts during the Olympic Games in London in 2012 as well as 136 bouts fought during the World Championships in Rio de Janeiro in 2013 were analyzed. Verification was performed by calculating indicators of technical and tactical preparation. The results show a significant correlation between the indicators of technical and tactical preparation and the ranking in the general classification of the analyzed competitions. There were no statistically significant correlations between the change of fighting rules and the level of the examined indices of technical and tactical preparation. The results of the study verified the appropriate method of preparation for the competitions analyzed.

Background: This research aimed to identify the most significant predictors of sports level using regression modeling. Methods: This study examined 16 judokas (aged 23 (±2.5)) from four weight categories, with four athletes in each category (66 kg, 73 kg, 81 kg and 90 kg). Each athlete was a member of the Polish National Team, an international master class (IM) or national master class (M). The tests were carried out twice (every two weeks) during the pre-competitive season in the morning, after a 10-min warm-up. The tests were performed according to the following protocol: Explosive Strength Lower Limbs (ExSLL) [W], Strength Endurance Lower Limbs (SELL) [%], Explosive Strength Upper Limbs (ExSUL) [W], Strength Endurance Upper Limbs (SEUL) [%]. The relationships between the dependent variable (ranking score) and the other analyzed variables (predictors) were estimated using the one-factor ridge regression analysis. Results: There were significant intergroup and intragroup differences in the results of explosive strength and strength endurance of the lower and upper limbs. The best predictors were identified using regression modeling: ExSLL, SELL, and SEUL. Conclusions: Increasing the value of these predictors by a unit should significantly affect the scores in the ranking table. Correlation analysis showed that all variables that are strongly correlated with the Polish Judo Association (PJA) ranking table scores may have an effect on the sports performance.