Objectives: This study aims to examine the acute effects of cyclic stretching versus static stretching on the shoulder flexibility, rotator cuff muscle strength, spike speed, and spike hit rate on target in adolescent volleyball players. Materials and methods: A total of 36 female volleyball players aged between 13 and 15 years were included in this study. Volleyball players were randomly divided into three groups: cyclic stretching group, static stretching group, and control group. Shoulder flexibility, rotator cuff muscle strength, spike speed, and spike hit rate on target were measured before and after the intervention. Results: Shoulder flexibility increased in cyclic stretching and static stretching groups after the intervention. Internal rotation strength increased in cyclic stretching group after the stretching intervention, compared to the control group. A significant reduction was observed in the scapular plane abduction strength in static stretching group after the intervention. Conclusion: Our study results suggest that cyclic stretching may be beneficial, as it increases both the shoulder flexibility and strength of young female volleyball players. In terms of volleyball performance, it can not be declared both cyclic stretching and static stretching have any effect.

ÖZETBu çalışma, akut fiziksel aktivitenin, antioksidan sistem parametreleri üzerine olan etkisinin incelenmesi amacıyla planlanmıştır. Bunun için araştırmaya 14-17 yaşları arasında Altay spor kulübünde düzenli antrenman yapan gönüllü 18 sporcu katılmıştır. Futbolcuların ilk gün antropometrik ölçümleri alınmış üç gün dinlendirildikten sonra 45'er dakikalık iki devreli maç yaptırılmıştır. Antioksidan sistem parametrelerinden SOD (Süperoksiddismutaz), CAT (Katalaz); lipid peroksidasyon sonucu oluşan MDA (Malondialdehid), E vitamini aktiviteleri ve hemogram değerleri egzersiz öncesi ve egzersiz sonrası alınan kan örneklerinden incelenmiştir.Futbolcuların % yağ oranı 10.9 ± 2.9, indirekt maxVO 2 değerleri 53.12 ± 9.88 ml./kg./ dk. olarak tespit edilmiştir. Eritrosit, hemoglobin, Hematokrit, MCV düzeyinde egzersiz öncesine göre artış bulunmuştur. Bu artış istatistiksel olarak anlamlıdır (p<0.05). Lökosit düzeyi artmış olmasına rağmen istatistiksel olarak anlamlı değildir (p >0.05 ).Akut egzersiz sonrasında istirahat durumuna göre SOD enzim aktivitesinde artış gözlenmiştir ve bu artış istatistiksel olarak anlamlıdır (p<0.05). CAT enzim aktivitesinde ise dinlenme durumuna göre normal sınırlar içinde artış gözlenmiştir ancak bu artış istatistiksel anlamlı değildir (p>0.05). Bu çalışmada akut egzersiz sonrasında MDA düzeyinde azalma meydana gelmiştir. Bu azalma istatistiksel olarak anlamlı bulunmuştur (p<0.05). MDA düzeylerinde saptanan düşüklük, antrenmanla antioksidan savunma sistemin güçlenmesi sonucunda serbest radikalleri ve buna bağlı olarak lipid peroksidasyonunu azalttığını düşündürmüştür. E vitamini düzeyinde akut egzersiz sonrasında ise dinlenme durumuna göre normal sınırlar içinde artış gözlenmiş, ancak bu artış istatistiksel olarak anlamlı değildir (p>0.05).Bu sonuçlar aerobik antrenmanın oksidatif strese adaptasyon yeteneğini geliştirdiğini ve bunun da lipid peroksidasyon düzeylerini azalttığını gösterebilir.Anahtar Kelimeler: Antioksidan Sistem, Lipid Peroksidasyon, Akut Egzersiz, Futbol. THE EFFECTS OF ACUTE EXERCISE ON THE PARAMETERS OF ANTIOXIDANT SYSTEM IN FOOTBALL PLAYERS ABSTRACTThe objective of this study was to investigate the effects of acute physical activity on antioxidant stress parameters including SOD (superoxide dismutase), and CAT (catalase) activities, the amount of MDA (malondialdehyde) and vitamin E and the hemogram values of football players. The research was performed on 18 football players (aged 14-17 years) of Altay football club in Turkey. Measurements were taken before and after a 90 min. football match and results compared.The maximum VO 2 (ml/kg/min) and average fat mass (%) of players was 53.12 +/-9.88 and 10.9 +/-2.9. Significant increases in the levels of erythrocyt, hemoglobin, hematocrit and MCV were observed after acute exercise as compared to their levels before exercise, but leukocyt level did not change significantly.Acute exercise significantly increased SOD activity but did not change CAT activity significantly (p<0.05). The MDA level declined significantly after acute e...

The vestibular system, visual and proprioceptive pathways provide information about control of posture, movement and balance. Loss of postural control directly leads to a greater incidence of falling in the elderly population causing serious health problems. One important neuromuscular mechanism instrumental in the control of posture and balance is the reflex system. However, the age-related changes of vestibular and visual systems and their relationship with the reflex system are not clear. The purpose of this study was to investigate the effects of age, the vestibular and the visual systems on the modulation pattern of the soleus H reflex. Seventeen neurologically healthy volunteers were categorized by age in two groups: young (n = 8, mean age = 22.1 ± 5.0 yr.) and elderly (n = 9, mean age = 59.3 ± 12.8 yr.). Maximal soleus H-reflex (H-max) and motor response (M-max) amplitudes were determined prior to testing at each condition while subjects were lying supine on a tilt table for standardization. Stimulation intensity was set to evoke a 5-10% M-wave on each trial. Participants received 5 test H-reflex stimuli in two conditions, static 60º and dynamic 60º on a tilt table. Both tilt conditions were performed with vision and no vision. A 3-way repeated-measures analysis of variance (ANOVA) 2 (groups: young/old) x 2 (condition: static/dynamic) x 2(vision: vision/no vision) was used to assess changes in H-reflexes. All data were expressed relative to the H-reflex amplitude at 0º static on the tilt table. The results showed a significant 3-way interaction (p = .038). The old group showed greater H-reflex amplitude in the no vision condition at static 60º (vision:0.97; no vision:1.23) whereas in the young group less modulation was demonstrated in the same condition (vision:1.15; no vision:1.12). These results suggest in young subjects the vestibular system produced a suppression of the H-reflex with or without visual input; however, in the old group vision was necessary for this suppression. The interaction between the visual and vestibular systems as we age needs to be further explored.

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