The study evaluates changes of muscle power and velocity during trunk rotations in ice-hockey players after six weeks of training in competition period. A group of 15 ice-hockey players performed 2 trunk rotations to each direction in a standing position with barbell of 6, 10, 12, 16, 20, 22, 26 kg placed on the shoulders. Basic biomechanical parameters during the movement were monitored using the FiTRO Torso Dyne system. Results showed that mean velocity in acceleration phase of trunk rotation significantly increased after 6 weeks of training at 6 kg (from 259 to 282.6 deg/s, p = 0.003) and 12 kg (from 218.8 to 244.1 deg/s p = 0.004). However, its values did not changed significantly during rotations with 10, 16, 20, 22 and 26 kg. Mean power of trunk rotation did not changed significantly with any of used weight. These findings indicate that there are only small changes in muscle power in competition period of ice hockey-players.
Milan Kováč, Eugen Laczo, Matej Vajda, Iveta Cihová and Jaroslava Babková
Endogenous hormones are essential for physiological reactions and influence the adaptation to weightlifting training by modulating anabolic and catabolic processes. It seems that testosterone and cortisol are playing a key role in anabolic and catabolic processes in resistance training. Eight elite Czech and Slovak weightlifters volunteered in present study. The testosterone and cortisol were measured in 4 testing sessions over 18 weeks during preparation and competition period. The training protocol consisted of three specific weightlifting exercises. The saliva samples were collected in 4 testing sessions, pre and 5 min, 15 min and 30 min after protocol, respectively. The basal level of salivary testosterone and cortisol remains unchanged during preparation and competition period. Also, acute testosterone response was not observed over the monitored period. However, acute decrease of cortisol were found between pre intervention and post 5 (p ≤ 0.01), 15 (p ≤ 0.01), and 30 min (p ≤ 0.05) during preparation periods. While in competition period was found significant decrease (p ≤ 0.05) only 5 min after testing protocol. The testosterone/cortisol ratio significantly increased during preparation periods (p ≤ 0.01), but not in competition period. Results indicated that the routine assessment of testosterone and cortisol may provide an effective way to monitor acute and chronic adaptive response to weightlifting training. Our results suggest that cortisol, not the testosterone is an important component of adaptation during elite weightlifting training.
Changes in serum lipid profile of elite volleyball players in the competition period
Study aim: To assess the changes in serum lipid profile of volleyball players in various phases of competition period characterised by creatine kinase activity.
Material and methods: A group of 14 Polish elite volleyball players aged 23 - 34 years were examined 3 times during the competition period lasting 10 weeks. Total cholesterol (TC), LDL, HDL, triacylglycerols (TG) and creatine kinase (CK) activity were determined in serum. Body fat content was determined from 4 skinfolds by Durnin's method.
Results: Creatine kinase activity was very high throughout the study period although significantly decreased in relation to the first examination; TC, LDL, TC/HDL and LDL/HDL gradually increased while HDL decreased. Nevertheless, the values of TC, HDL, LDL and LDL/HDL were within normal limits in all subjects throughout the study.
Conclusions: The changes in lipid profile may be regarded as transitory and of no significant impact on the risk of cardiovascular diseases as in all cases they were within physiological ranges.
Romain Bouzigon, Gilles Ravier, Benoit Dugue and Frederic Grappe
exposure or have been subjected to colder temperatures than subjects with a higher BMI.
Globally, a 3-min exposure at –130 °C is well tolerated by athletes and can be used during a heavy competitionperiod and/or during a training period when the load of physical exercise is very important. PBC is not perceived as extremely uncomfortable or stressful by most athletes; however, special attention should be given to female athletes with a low BMI as they seem to be much more sensitive to cold. Our recently published review emphasizes that further studies should be
Robert Podstawski, Michał Boraczyński, Danuta Nowosielska-Swadźba and Danuta Zwolińska
Study aim: Regular exercise training is thought to modify cardiac autonomic control. One of the body’s responses to training stimuli is heart rate variability (HRV). The use of HRV in the management of sport training is a common practice. The objective of the present study was to assess the impact of the physical activity level on HRV of 1st league national volleyball players prior to and during the competition period.
Materials and methods: The study involved 11 players whose HRV was evaluated during the two analysed training periods. Selected indicators of spectral analysis (total power, %VLF, % LF, % HF powers, LF n.u, HF n.u, and LF/HF powers) as well as time analysis (HR, RR, RMSSD, NN50) were assessed on the basis of recordings.
Results: The studies conducted in the pre-competition and competition periods showed significant differences in the parameters of spectral VLF% analysis and time NN50 analysis. In the competition period, a significant increase in VLF [%] may be the result of increased psycho-physical arousal, when compared to the pre-competition period. ]
Conclusions: Resting bradycardia, assessed on the basis of time analysis indicators, may be the result of internal changes in the sinus node, which reflects the impact of long-term training on the cardiac conduction system. A high level of physical activity of volleyball players in the tested periods could have contributed to a reduction in vagal tone and a shift in the balance of the autonomic nervous system in the direction of the sympathetic system, which may be the result of overtraining
Adam Czaplicki, Marcin Śliwa, Paulina Szyszka and Jerzy Sadowski
Introduction. The aim of the study was to determine the changes in the peak torque of the knee extensors and flexors of the dominant lower limb, the shoulder internal and external rotators of the dominant upper limb, and the shoulder extensors and flexors of the dominant upper limb as well as the changes in jump height in volleyball players during the annual training macrocycle.
Material and methods. The study involved 13 volleyball players from a Polish second-league team. The measurements were performed five times: before the preparation period (T1), at the beginning of the competitive season (T2), in the middle (T3) and at the end of the first competition period (T4), and after the competitive season (T5). The torque of the knee muscles and shoulder rotators was measured in isokinetic conditions, and the torque of the shoulder extensors and flexors was assessed in isometric conditions. Jumping ability was tested using a piezoelectric platform.
Results. We observed statistically significant differences (p < 0.05) in jump height and relative peak torque between the measurements, except for the torque of the shoulder external rotators and flexors. The results of multiple factor analysis based on 5 sets composed of 5 strength variables revealed differences between subjects and measurement sessions.
Conclusions. The results obtained indicate that strength and jumping ability should be assessed regularly during the competitive season. The findings of the study suggest that it is necessary to modify the training methods used during the preparation period and individualize the training in the final phase of the competition period.
Tomasz Sacewicz, Sławomir Bodasiński, Marcin Śliwa, Paulina Szyszka, Zenon Mazur and Adam Czaplicki
Introduction. The aim of the study was to determine the torque of the knee extensors and flexors of the lead lower limb, the torque of the shoulder extensors and flexors of the dominant upper limb, and the torque generated by the muscles of the kinematic chain going from the trail lower limb to the hand of the dominant limb in male handball players during the annual training macrocycle. Changes in jump height and throwing velocity were also investigated. Material and methods. The study involved 13 handball players from a Polish second-league team. The measurements were performed four times: at the beginning of the preparation period, at the beginning of the season, at the end of the first part of the season, and at the end of the second part of the season. Torque was measured in isokinetic and isometric conditions. Jumping ability was tested using a piezoelectric platform, and throwing velocity was measured with a speed radar gun. Results. The study found statistically significant differences between the relative torque values of the knee extensors (p < 0.002) and flexors (p < 0.003) of the lead leg measured in isokinetic conditions between the first three measurements and the final one. Isokinetic measurement of the torque of the muscles of the kinematic chain going from the trail leg to the hand of the dominant arm decreased in a statistically significant way at the end of the season. As for the results of the measurement of the torque of the shoulder extensors and flexors in static conditions, no statistically significant differences were observed between the four measurements. However, statistically significant differences were noted in jumping ability and throwing velocity in the annual training macrocycle. Conclusions. The results of the study indicate that there is a need to perform regular assessments of players’ strength and jumping ability during the competition period. There is a need to modify the training methods used during the preparation period and in the second part of the season as well as to individualise training at the end of the competition period.
Introduction. Since the competition period has been prolonged in modern football, it is important to know if a shortened preparatory phase is enough to improve motor fitness preparation. This study analysed the changes in the level of physical fitness in second-league soccer players with respect to training conducted during the preparatory period.
Material and methods. Speed (5-m and 30-m sprint), endurance (progressive test), and power (Counter Movement Jump) were tested in 21 players at the beginning and at the end of the preparatory phase.
Results. The results obtained indicate a significant improvement in physical capacity parameters as well as speed and strength abilities measured using 5-m and 30-m running speed tests and the CMJ test for muscle power. In the progressive test measuring anaerobic threshold speed, the players active in the central section of the pitch (centre-backs and central midfielders) achieved the best results, while in the speed trials and explosive strength trials, side-backs and side midfielders achieved the best results.
Conclusions. During the winter preparatory season, the most significant changes in the physical fitness of soccer players were observed in aerobic endurance expressed as threshold speed (an increase of 1.2 km/h) and running speed measured as the time needed to cover a distance of 5 m (time reduced by 0.04 s) and 30 m (time reduced by 0.07 s). These traits are crucial in the preparation of soccer players for league matches and have the greatest impact on their performance in sports competitions.
Study aim: Recent evidence has revealed a reduction in the strength of correlation between ratings of perceived exertion and a heart rate (HR) derived training load in elite field hockey players during competition. These competitive periods involve sustained levels of cardiovascular performance coupled with considerable time performing above the anaerobic threshold. As such, the purpose of this investigation was to examine the magnitude of correlation between ratings of perceived exertion and time spent above threshold and two HR derived training loads.
Material and methods: Seventeen (n = 17) international caliber female field hockey players competing as a national team were monitored over four matches during a seven-day competition period within the 2016 Olympic Cycle. Cardiovascular indices of exercise intensity were derived from HR dynamics and were quantified through estimating time spent above anaerobic threshold (LT2), the Edwards training load model (TLED) and the Polar Training Load (TLPOL). Sessional ratings of perceived exertion (sRPE) were recorded after each match.
Results: 64 samples were recorded for analysis. HR derived (TLED& TL POL) and sRPE training loads remained comparable between matches. A large correlation (p = 0.01) was observed between sRPE and each heart rate derived training load (TLED& TLPOL). An unremarkable relationship (p = 0.06) was revealed between time spent above LT2 and sRPE.
Conclusions: Our results demonstrate HR derived training loads (TLPOL& TLED) exhibit a stronger correlation with sRPE than time spent above LT2 in elite field hockey players during competition.
Paulina Szyszka, Janusz Jaszczuk, Jarosław Sacharuk, Florian Parnicki and Adam Czaplicki
Introduction. The aim of the current study was to examine the relationship between knee and elbow isometric muscle torque values and the results obtained in special and specific exercises in young weightlifters. Material and methods. The study involved eight young weightlifters (age: 19.9 ± 4.3 years; height: 176.8 ± 10.6 cm; weight: 69.0 ± 19.7 kg - pretest, 70.9 ± 21.6 - posttest). Their performance put them in the second and third top classes of weightlifters their age according to the Polish norms for weightlifting (the so-called ‘national class’ and ‘first class’ in the Polish system, which are lower than the ‘international class’). The differences between the values obtained in the first measurement of torque performed at the beginning of the preparation period and those obtained at the beginning of the immediate pre-competition period were compared with the differences in the maximal load lifted in special and specific exercises. Results. The training that the weightlifters underwent during the preparation period caused a significant increase in the relative torque values of the knee extensors (0.56 Nm/kg on average, p ≤ 0.047) and those of the elbow flexors (0.35 Nm/kg, p ≤ 0.0002). Significant differences (p ≤ 0.05) were observed between the results obtained in all of the special and specific exercises examined. A statistically significant relationship was also found between the changes in relative torque values and the results achieved in special and specific exercises. Conclusions. The regression equations derived in the study can help predict sports performance outcomes based on the results of laboratory tests.