Isokinetics and Exercise Science - Volume 27, issue 4

Authors: Barrenetxea-Garcia, Josu | Torres-Unda, Jon | Esain, Izaro | Gil, Susana M.

Article Type: Research Article

Abstract: BACKGROUND: In countries where water polo is a minority sport, coaches often recruit young players to senior teams. OBJECTIVE: To explore whether young water polo players are ready to train and play with older players from a physical and strength perspective. METHODS: Forty-four adolescent and senior water polo players (20 women and 24 men) were evaluated on full anthropometry, absolute and relative isokinetic muscle strength of shoulder internal and external rotator muscles (60 and 240 ∘ /s) and hand grip strength. RESULTS: The strength of the internal …rotators was significantly greater than that of the external rotators in both sexes and age groups. Senior male players had significantly higher values for variables related to body size and absolute strength in these muscle groups compared to their adolescent counterparts but these differences were not observed among women. CONCLUSIONS: Adolescent female players but not male players may be physically prepared to compete and train with senior teams. Show more

Keywords: Team sport, body size, adolescence, strength training, performance

DOI: 10.3233/IES-192189

Citation: Isokinetics and Exercise Science, vol. 27, no. 4, pp. 325-332, 2019

Authors: Ünver, Evrim | Cinemre, Şükrü Alpan

Article Type: Research Article

Abstract: BACKGROUND: The circadian rhythm (CR) is a 24-hour cyclic period that influences a wide array of physiological systems and performance sports. However, its specific effect on drop jump (DJ) scores have not been studied. OBJECTIVE: To investigate the effect of circadian rhythm on DJ performances. METHODS: Thirty-three healthy university students (men, n = 16, age: 23.47 ± 2.9 years; fewomen, n = 17, age: 22.25 ± 2.27 years) participated in this study. Subjects were tested twice, over two …separate days, once in the morning and once in the evening. Subjects started from a drop height of 20 cm and continued until the height where the reactive strength index (RSI) started to decrease. This height was recorded as the optimal drop height (ODH). Ground contact time (GCT) and jump height were also recorded. RESULTS: The ODH values were similar between testing sessions for both genders (p > 0.05). A significant increase in jump height during the evening session was observed in men (p = 0.005, d = 0.80). The RSI values increased significantly in men (p = 0.006, η 2 = 0.77) while GCT was similar in both genders (p > 0.05). CONCLUSION: In men, the optimal time of day for DJ explosive training is the evening. Women may benefit from this type of training both during morning and evening sessions. Show more

Keywords: Circadian rhythm, drop jump, reactive strength index, optimal drop height, jump height, ground contact time

DOI: 10.3233/IES-192174

Citation: Isokinetics and Exercise Science, vol. 27, no. 4, pp. 333-339, 2019