ABSTRACT
BACKGROUND: Current research on athletic performance focuses on genetic variants that contribute significantly to individuals' performance. ACTN3 rs1815739 and PPARA-α rs4253778 gene polymorphisms are variants frequently associated with athletic performance among different populations. However, there is limited research examining the pre-and post-test results of some variants of athletic performance in soccer players. Therefore, the presented research is to examine the relationships between the ACTN3 rs1815739 and PPARA-α rs4253778 gene polymorphisms and athletic performance improvement rates in adaptations to six weeks of training in elite soccer players using some athletic performance tests. METHODOLOGY: Twenty-two soccer players between the ages of 18 and 35 voluntarily participated in the study. All participants were actively engaged in a rigorous six-day-a-week training program during the pre-season preparation period. Preceding and following the training program, a battery of diverse athletic performance tests was administered to the participants. Moreover, Genomic DNA was extracted from oral epithelial cells using the Invitrogen DNA isolation kit (Invitrogen, USA), following the manufacturer's protocol. Genotyping was conducted using real-time PCR. To assess the pre- and post-test performance differences of soccer players, the Wilcoxon Signed Rank test was employed. RESULTS: Upon analyzing the results of the soccer players based on the ACTN3 genotype variable, it was observed that there were no statistically significant differences in the SJ (Squat Jump), 30m sprint, CMJ (Counter Movement Jump), and DJ (Drop Jump) performance tests (p > 0.05). However, a statistically significant difference was identified in the YOYO IRT 2 (Yo-Yo Intermittent Recovery Test Level 2) and 1RM (One Repetition Maximum) test outcomes (YOYO IRT 2: CC, CT, and TT, p = 0.028, 0.028, 0.008, 0.000, respectively; 1RM: CC, CT, and TT, p = 0.010, 0.34, 0.001, respectively). Regarding the PPARA-α genotype variable, the statistical analysis revealed no significant differences in the SJ, 30m sprint, CMJ, and DJ performance tests (p > 0.05). Nevertheless, a statistically significant difference was observed in the YOYO IRT 2 and 1RM test results (YOYO IRT 2: CC, CG p = 0.001, 0.020; 1RM: CC, p = 0.000) CONCLUSIONS: The current study demonstrated significant enhancements in only YOYO INT 2 and 1RM test outcomes across nearly all gene variants following the six-day-a-week training program. Other performance tests, such as the 30m sprint, SJ, CMJ, and DJ tests did not exhibit statistically significant differences. These findings contribute novel insights into the molecular processes involving PPARA-α rs4253778 and ACTN3 rs1815739 that underpin enhancements in endurance (YOYO INT 2) and maximal strength (1RM) aspects of athletic performance. However, to comprehensively elucidate the mechanisms responsible for the association between these polymorphisms and athletic performance, further investigations are warranted. It is thought that the use of field and genetic analyses together to support each other will be an important detail for athletes to reach high performance.
ABSTRACT
This study was designed to investigate the additive effect of EMG-biofeedback in rehabilitation of knee osteoarthritis. Forty patients, aged 45-70, with the diagnosis of knee osteoarthritis according to American College of Rheumatology (ACR) criteria were taken into the study. The patients were randomly assigned in two groups. One group (n = 20) received strengthening exercise program with EMG-biofeedback while the other group (n = 20) had the same exercise program without biofeedback for 3 weeks. The clinical outcome was assessed on the basis of pain with visual analog scale (VAS), function with Western Ontario McMaster Osteoarthritis Index (WOMAC) and quality of life with Nottingham Health Profile (NHP). Quadriceps strength was measured with Cybex isokinetic dynamometer, isokinetically at the angular velocities of 60 and 180 degrees /s and isometric strength at 65 degrees of knee flexion. Pain, WOMAC scores and muscle strength improved in both groups but there was no statistically significant differences between two groups (p > 0.05). In both groups physical mobility, pain scores of NHP improved significantly (p < 0.001) while in EMG-biofeedback group energy and sleep scores also improved after treatment (p < 0.05). As reported in the literature, in our study, strengthening exercises improved pain, function, muscle strength and quality of life in patients with knee osteoarthritis. But it seems that there is no significant additive effect of EMG-biofeedback to regular strengthening exercise program in these patients.
