STRENGTH POTENTIAL OF YOUNG MEN AND WOMEN

Muscle strength is a basic human feature. It may be diagnosed through fitness tests or through dynamometry of muscle groups. Measurements of several muscle groups at a time with a back dynamometer, or a shoulder dynamometer (strain gauge or inertial dynamometer) can not answer which element (which muscle group) is the weakest within the entire chain. An approach proposed by Fidelus (1967) takes into account the capabilities of isolated muscle groups. This approach is widely used all over the world. Fidelus proposed assessment of 10 muscle groups acting in the sagittal plane. These are the flexors and extensors of: forearm, arm, foot, calf, thigh, and trunk, Multiplying a value of resistance force read-out from the dynamometer by a moment arm one can obtain a value for the moment of force. This moment is equal to the moment of muscle strength. Unfortunately, this approach did not allow to obtain a value of muscle strength alone, since one did not know a value of muscle strength lever arm. Contemporary knowledge gives us a possibility of obtaining data on muscle strength lever arms of some joints - Erdmann (2001). The aim of this paper is obtaining data on muscle strength for main body parts of contemporary young population

KINEMATICS OF MARATHON RUNNING TACTICS PART ONE: COURSE PROFILE

The paper presents a description of geometry of marathon courses. The following courses were taken into account: Edmonton 2001 (IAAF World Championships), Boston 2002 (city marathon), Berlin 2002 (city marathon), Athens 2004 (Olympic Games). Based on course profile (for every 1 km) coefficient of course difficulty was calculated. The most flat course profile was that of Berlin Marathon, the toughest profile was that of Athens Marathon

INVESTIGATIONS ON TECHNIQUE AND TACTICS OF RACE WALKING DURING OLYMPIC GAMES ATHENS 2004 – FIRST ANNOUNCEMENT

The paper presents preliminary information devoted to the investigations on technique and tactics of race walkers participating at distances of 20 (males and females) and 50 (males) km during Olympic Games ‘Athens 2004’

Population, economic and geographic predictors of nations' medal tallies at the Pyeongchang and Tokyo Olympics and Paralympics

Purpose: Ranking of nations by medal tally is a popular feature of the Olympics, but such ranking is a poor measure of sporting prowess or engagement until the tallies are adjusted for major factors beyond the control of individual nations. Here we estimate and adjust for effects of total population, economy expressed as gross domestic product per capita, absolute latitude and Muslim population proportion on total medal counts in female, male, mixed and all events at the Pyeongchang winter and Tokyo summer Olympics and Paralympics. Methods: The statistical model was multiple linear over-dispersed Poisson regression. Population and economy were log-transformed; their linear effects were expressed in percent per percent units and evaluated in magnitude as the factor effects of two between-nation standard deviations (SD). The linear effect of absolute latitude was expressed and evaluated as the factor effect of 30° (approximately 2 SD). The linear effect of Muslim proportion was expressed as the factor effect of 100% vs. 0% Muslim. Nations were ranked on the basis of actual vs. predicted all-events medal counts. Results: At the Pyeongchang Olympics, effects of population and economy were 0.7–0.8 %/% and 1.1–1.7 %/% (welldefined extremely large increases for 2 SD), factor effects of 30° of latitude were 11–17 (welldefined extremely large increases), and factor effects of 100% Muslim population were 0.08–0.69 (extremely large to moderate reductions, albeit indecisive). Effects at the Tokyo Olympics were similar in magnitude, including those of latitude, which were surprisingly still positive although diminished (large to very large increases). Effects at the Pyeongchang and Tokyo Paralympics were generally similar to those at the Olympics, but the effects of economy were diminished (large to very large increases). After adjustment of medal tallies for these effects, nations that reached the top-10 medalists in both winter games were Austria, Belarus, Kazakhstan, Slovakia and Ukraine, but only Azerbaijan reached the top-10 in both summer games. Conclusion: Adjusting medal counts for demographic and geographic factors provides a comparison of nations' sporting prowess or engagement that is more in keeping with the Olympic ideal of fair play and more useful for nations' Olympic-funding decisions

Sensor analysis for the assessment of biomechanical parameters in endurance runners: a systematic review

Problem Statement: This systematic review focuses on the use of sensors to improve performance in endurance athletes by analyzing biomechanical parameters. Approach: The use of sensors in endurance sports has gained popularity in recent years, allowing athletes and coaches to measure and analyze different biomechanical parameters in real-time. Purpose: The main purpose of this systematic review is to answer the question of how sensors can be used and applied to improve performance in endurance runners by analyzing the biomechanical parameters they provide. Methods: Systematic review analyzing related keywords such as biomechanics, kinematics, kinetics, running, triathlon, ultra running, trail running, Stryd, SHFT, Runscribe, and performance, through scientific research articles from the database of the Electronic Library of the Isabel I University dated 02/2023 in English. A total of 192 investigations were found, of which 168 were excluded. After a detailed review, 15 relevant investigations were included. Results: Sensors can be useful to measure biomechanical parameters such as cadence, stride length, leg spring stiffness, ground contact time, and vertical oscillation, which can help to improve performance in endurance athletes. Conclusions: Sensors are a suitable tool to analyze performance improvement in endurance athletes by analyzing biomechanical parameters. However, it is important to highlight that not all sensors are similar, that it is necessary to carefully select the most suitable ones for each specific situation, and that biomechanics is also conditioned in each athlete, so universal rules cannot be established

Accuracy of Jump-Mat Systems for Measuring Jump Height

Vertical-jump tests are commonly used to evaluate lower-limb power of athletes and nonathletes. Several types of equipment are available for this purpose. Purpose: To compare the error of measurement of 2 jump-mat systems (Chronojump-Boscosystem and Globus Ergo Tester) with that of a motion-capture system as a criterion and to determine the modifying effect of foot length on jump height. Methods: Thirty-one young adult men alternated 4 countermovement jumps with 4 squat jumps. Mean jump height and standard deviations representing technical error of measurement arising from each device and variability arising from the subjects themselves were estimated with a novel mixed model and evaluated via standardization and magnitude-based inference. Results: The jump-mat systems produced nearly identical measures of jump height (differences in means and in technical errors of measurement ≤1 mm). Countermovement and squat-jump height were both 13.6 cm higher with motion capture (90% confidence limits ±0.3 cm), but this very large difference was reduced to small unclear differences when adjusted to a foot length of zero. Variability in countermovement and squat-jump height arising from the subjects was small (1.1 and 1.5 cm, respectively, 90% confidence limits ±0.3 cm); technical error of motion capture was similar in magnitude (1.7 and 1.6 cm, ±0.3 and ±0.4 cm), and that of the jump mats was similar or smaller (1.2 and 0.3 cm, ±0.5 and ±0.9 cm). Conclusions: The jump-mat systems provide trustworthy measurements for monitoring changes in jump height. Foot length can explain the substantially higher jump height observed with motion capture

Strength, Endocrine, and Body Composition Alterations Across Four Blocks of Training in an Elite 400 M Sprinter

The ability to produce force rapidly has the potential to directly influence sprinting performance through changes in stride length and stride frequency. This ability is commonly referred to as the rate of force development (RFD). For this reason, many elite sprinters follow a combined program consisting of resistance training and sprint training. The purpose of this study was to investigate the strength, endocrine and body composition adaptations that occur during distinct phases of a block periodized training cycle in a 400 m Olympic level sprinter. The athlete is an elite level 400 m male sprinter (age 31 years, body mass: 74 kg, years of training: 15 and Personal Best (PB): 45.65 s). This athlete completed four distinct training phases of a block periodized training program (16 weeks) with five testing sessions consisting of testosterone:cortisol (T/C) profiles, body composition, vertical jump, and maximum strength testing. Large fluctuations in T/C were found following high volume training and the taper. Minor changes in body mass were observed with an abrupt decrease following the taper which coincided with a small increase in fat mass percentage. Jump height (5.7%), concentric impulse (9.4%), eccentric impulse (3.4%) and power ratio (18.7%) all increased substantially from T1 to T5. Relative strength increased 6.04% from T1 to T5. Lastly, our results demonstrate the effectiveness of a competitive taper in increasing physiological markers for performance as well as dynamic performance variables. Block periodization training was effective in raising the physical capabilities of an Olympic level 400 m runner which have been shown to directly transfer to sprinting performance

Effect of a simulated match on lower limb neuromuscular performance in youth footballers - a two year longitudinal study

The aim of this study was to explore the effects of simulated soccer match play on neuromuscular performance in adolescent players longitudinally over a two year period. Eleven players completed all measurements in both years of the study (1st year: age 16.0 ± 0.4 y; stature 178.8 ± 6.4 cm; mass 67.5 ± 7.8 kg; maturity-offset 2.24 ± 0.71 y). There was a significant reduction in hamstring strength after simulated match by the soccer-specific aerobic field test (SAFT90), with four out of eight parameters compromised in U16s (4.7 – 7.8% decrease) and six in the U17s (3.1 – 15.4%). In the U17s all of the concentric quadriceps strength parameters were decreased (3.7 – 8.6%) as well as the vastus lateralis and semitendinosus firing frequency (26.9 – 35.4%). In both ages leg stiffness decreased (9.2 – 10.2%) and reactive strength increased pre to post simulated match (U16 8.0%; U17 2.5%). A comparison of changes between age groups did not show any differences. This study demonstrates a decrease in neuromuscular performance post simulated match play in both ages, but observed changes were not age dependent