A well-established positive relationship exists between strength training and soccer performance, as well-designed resistance-based programs can enhance both aerobic and anaerobic capacities, which are essential for the sport. The present study aimed to examine the long-term effects of complex and contrast strength training on aerobic and anaerobic endurance performance in soccer players. The study sample consisted of 30 male athletes (mean height: 180.53 ± 6.339 cm; mean weight: 72.97 ± 7.421 kg; mean age: 18.10 ± 0.712 years) from the Gaziantep F.K. soccer team, competing in the TFF Development League during the 2024–2025 season. Utilizing an experimental design with pre-test and post-test control groups, the research employed quantitative methods to assess changes over time. Baseline aerobic and anaerobic endurance tests were conducted over the first two days, after which participants were randomly assigned to one of three groups: complex training, contrast training, or a control group. In addition to regular team practices, the complex and contrast training groups completed 24 training sessions over eight weeks (three sessions per week), while the control group continued with standard weekly training only. Following the intervention period, post-tests for aerobic and anaerobic endurance were administered. Data analysis involved paired sample t-tests for within-group comparisons, one-way ANOVA for between-group differences, and LSD tests for multiple comparisons, with a significance level set at p < 0.05. The results indicated that both complex and contrast training significantly improved aerobic and anaerobic endurance compared to the control group (p < 0.05), with notable gains observed in the 30-15 Intermittent Fitness Test (IFT) and Vertical Jump Test. However, no significant differences were found between the complex and contrast training groups (p > 0.05). In conclusion, the eight-week intervention yielded significant improvements in both aerobic and anaerobic performance among soccer players, suggesting that incorporating complex and contrast strength training into conditioning programs can effectively enhance soccer-specific endurance capacities. Article visualizations:

Background. Considering that breathing strategies are essential for athletic performance, insufficient scientific data exists to understand how they operate. Objectives. This study investigated the effect of conscious diaphragm muscle-based respiratory muscle exercise on respiratory muscle strength and function. Methods. For that, four groups (IMT-DF (inspiratory muscle training using diaphragm), IMT ...

Objectives: Isometric strength training is widely used to enhance athletic performance and support rehabilitation. However, few studies compare the effects of dynamometer-based and suspension-based isometric training on performance, and the effects of these methods remain unclear. This study compares the effects of dynamometer-based and suspension-based isometric training on muscle asymmetry, balance, estimated maximal strength, anaerobic power, and isokinetic strength in trained male athletes. Methods: This study included 16 healthy male athletes aged 18 to 21 years (mean age: 18.81 ± 1.16 years; height: 178.06 ± 4.65 cm; body weight: 74.25 ± 4.32 kg; BMI: 23.43 ± 1.24 kg/m ² ; body fat: 14.29 ± 1.55%). Participants were randomly assigned to either the TRX-based isometric training group (TRG, n=8) or the dynamometer-based isometric training group (DTG, n=8). Both groups performed isometric strength training based on the principle of progressive overload for eight weeks. The TRG group completed a predetermined series of four exercises three days per week. In contrast, the DTG group performed 6-second isometric contraction series in both flexion and extension positions for each leg three days per week. We assessed data normality using the Shapiro-Wilk test and calculated the mean and standard deviation. The relationship between pre-test and post-test measurements in the TRG and DTG groups was analyzed using a two-way repeated-measures analysis of variance (ANOVA; time × group); the level of statistical significance was set at p <.05. Results: A significant main effect of time from the pretest to the posttest was found for the parameters of isokinetic peak torque, OSI, MLI, peak power, average power, and estimated 1RM (p <.05). In contrast, no significant main effect of time was observed for muscle asymmetry, API, and time to reach peak power (p>.05). Furthermore, it was stated that neither the group effect nor the time × group interaction showed a statistically significant effect on any of the performance parameters (p>.05). Conclusion: In conclusion, while an eight-week TRX and dynamometer-based isometric training program resulted in significant changes in selected strength, balance, and anaerobic power parameters attributable to the main effect of time, no significant changes were observed in group effects or time × group interactions for any of the measured parameters.

Caffeine supplementation is one of the most commonly used ergogenic aids among soccer players. However, research shows conflicting results regarding the effects of different caffeine forms on muscle strength and power. This study investigated the impact of a high-dose caffeine mouth rinse on isokinetic knee extensor and flexor strength of the dominant leg at high (180°/s−1) and low (60°/s−1) angular velocities. Eight young male soccer players were randomly assigned to three conditions. Ten seconds before the isokinetic strength tests, participants either rinsed with an aspartame solution containing 750 mg of caffeine (Experimental), a calorie-free aspartame solution (Placebo) or did not use any solution (Control). Participants continued the mouth rinse for 10 s. Isokinetic strength measurements were performed at angular velocities of 60°/s−1 (5 repetitions) and 180°/s−1 (15 repetitions) in all interventions. Peak torque (Nm), the H/Q ratio, time to peak torque (ms), and average peak torque (Nm) in extension and flexion were analyzed. Data were tested for normality using the Shapiro-Wilk test, followed by one-way ANOVA and LSD post hoc tests (significance set at p < 0.05). According to the results, a significant difference was found in the H/Q ratio and time to peak torque at the angular velocity of 60°/s−1 (p < 0.05, η² = 0.290; 0.306). At the angular velocity of 180°/s−1, no significant differences were found among the interventions (p > 0.05). These findings suggest that a high dose of the caffeine mouth rinse was effective at the lower angular velocity (60°/s−1), but had no effect on peak torque at the higher angular velocity (180°/s−1).