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The ongoing development of the modern society may also be easily noticed in sports. Currently, to be able to compete at the highest level at major sporting events, it is essential to conduct scientific research to estimate the individual potential and skill level of an athlete. The aim of this study was to assess the anaerobic endurance in men competing in the running events of 400 m/400 m hurdles based on the estimation of maximum power, as well as selected biochemical and physiological parameters measured in a cardiac stress test at a supramaximal intensity. Seven athletes participated in the study and were subjected to a modified version of the Wingate test (Bar-Or, Dotan, Inbar, 1997; Bar-Or, Inbar, Skinder, 1996) which involved performing three runs of a 12‑second endurance test on a cycloergometer at short intervals. This modification of the test allowed a more precise observation and a better understanding of the physiological and biochemical changes that decrease the efficiency as a result of repeated physical effort, which may significantly affect the assessment of the preparation of an athlete, and thus the assessment of the training process. The most significant changes in the course of the conducted study were observed in the values of the following biochemical parameters: glucose levels, acid–base balance of the blood and lactate levels.
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The Borg Scale at high altitude

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Introduction: The Borg Scale for perceived exertion is well established in science and sport to keep an appropriate level of workload or to rate physical strain. Although it is also often used at moderate and high altitude, it was never validated for hypoxic conditions. Since pulse rate and minute breathing volume at rest are increased at altitude it may be expected that the rating of the same workload is higher at altitude compared to sea level.Material and methods: 16 mountaineers were included in a prospective randomized design trial. Standardized workload (ergometry) and rating of the perceived exertion (RPE) were performed at sea level, at 3,000 m, and at 4,560 m. For validation of the scale Maloney-Rastogi-test and Bland-Altmann-Plots were used to compare the Borg ratings at each intensity level at the three altitudes; p < 0.05 was defined as significant.Results: In Bland-Altmann-Plots more than 95% of all Borg ratings were within the interval of 1.96 x standard deviation. There was no significant deviation of the ratings at moderate or high altitude. The correlation between RPE and workload or oxygen uptake was weak.Conclusion: The Borg Scale for perceived exertion gives valid results at moderate and high altitude – at least up to about 5,000 m. Therefore it may be used at altitude without any modification. The weak correlation of RPE and workload or oxygen uptake indicates that there should be other factors indicating strain to the body. What is really measured by Borg’s Scale should be investigated by a specific study.
EN
During intensive skiing, at each turn, in particular towards the end of the turning steering phase, eccentric work of the lower limb muscles occurs (predominantly of the quadriceps femoris), which is the direct cause of damage within muscle cells. A few or more than ten hours after intensive physical effort the symptoms of delayed onset muscle soreness may appear, which is mainly a result of the micro-damage within the myocytes.The following procedure can be proposed for prevention of muscle soreness for skiers: around a week before first day of skiing in the season, skiers should perform a series of intensive physical exercises involving eccentric contractions, thus inducing delayed muscular soreness. The exercises may involve for example: downhill running, preferably down a steep slope, running down stairs, deep knee bend jumps, deep knee bend jumps over an obstacle, jumping to the ground from a certain height, sit-ups on one or both feet, etc. The exercises should lead considerable local fatigue, in particular of the lower limb muscles, so that muscle soreness occurs on the second day, in particular in the frontal part of the thighs. After approximately two days the pain will alleviate, while after a week the strength of the muscles will return to its pre-exercise condition. This should considerably reduce, or even remove, delayed muscle soreness after skiing, which will not only help skiers use their time more effectively but will also be crucial to the skiers' safety.
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