Journal of science and medicine in sport最新文献

Objectives: The study aimed to examine the effects of exercise-induced muscle damage on running kinetics.

Design: Twenty-six adult recreational male runners performed 60 min of downhill running (-10 %) at 65 % of maximal heart rate. Running gait changes, systemic and localized muscle damage markers were assessed pre - and post-exercise induced muscle damage protocol.

Methods: Running gait was analyzed using a 3D treadmill at baseline, immediately post, 24 h, and 48 h to determine changes in running pressure sway and vertical ground reaction forces. Blood markers, subjective pain perception, and magnetic resonance imaging utilizing T₂ relaxation time of the thigh muscles assessed systemic and localized damage. Linear mixed-effects models examined changes over time.

Results: Significant decreases were found in the left leg's first (-454.0 to -396.1, P < 0.05) and second (-532.8 to -498.2, P < 0.05) VGRF peaks across all time points compared to baseline. The right leg showed reductions in the first vertical ground reaction forced peak at immediately post (-348.4, P = 0.036) and the second peak at immediately post and 24 h (-467.4 and -396.8, P < 0.05). Creatine kinase increased significantly (P < 0.001) at 24 h and 48 h compared to baseline. The anterior thigh muscle compartment showed significant (P < 0.05) increases in mean T₂ values 1 h following exercise protocol remained elevated up to 48 h. Negative correlations were identified between running biomechanics to local and systemic muscle damage markers.

Conclusions: Running biomechanics remained impaired for up to 48 h following exercise induced muscle damage and correlated with markers of muscle damage using magnetic resonance imaging.

Objectives: Polycystic ovary morphology and ovarian cysts are frequent and usually asymptomatic in young female individuals. The present study is the first to examine ovarian sonographic findings in asymptomatic female athletes from Iran. This study aimed to evaluate the frequency of such sonographic findings in healthy female athletes on a screening basis.

Methods: In this cross-sectional observational study, 455 females from 16 provinces of Iran were evaluated by trans-abdominal sonography during their routine pre-participation medical evaluation.

Results: The mean age of participants was 21.8 years (SD 5.3). The mean age at the beginning of exercise was 14.20 years (SD = 4.25). Menarche occurred at 11-20 years with a mean of 13.5 years (SD 1.5). Judokas had the lowest (12.1 years), and football players had the highest menarche age (14.6 years; as compared to 12.8 years in the Iranian female population). In 87.5 % of participants, the sonographic findings were within normal limits. 4.8 % of all examinations revealed polycystic ovary morphology (PCOM), 5.7 % of participants had a simple cyst(s), and 20.8 % of cysts had diameters >49 mm. In those athletes who began regular performance-oriented training before menarche, PCOM was found in only 2.4 %. There was a significant positive linear association between BMI groups and PCOM (p = 0.003), but not for simple cysts. Frequency of PCOM (p < 0.001) as well as ovarian cysts (p = 0.012) were significantly different among studied sport types. There was a significant positive correlation between delayed menarche status and PCOM (p = 0.017). However, no such relationship was found for simple cysts.

Conclusions: Maintaining a healthy body mass index and beginning regular exercise before menarche may have a preventative effect for polycystic ovary morphology in female athletes.