Kamiş, O, Gürses, VV, Şendur, HN, Altunsoy, M, Pekel, HA, Yıldırım, E, and Aydos, L. Low-load resistance exercise with blood flow restriction vs. high-load resistance exercise on hamstring muscle adaptations in recreationally trained men. J Strength Cond Res 38(10): e541–e552, 2024—Low-load resistance exercise with blood flow restriction (BFR-RE) has been suggested as a viable alternative exercise for traditional high-load resistance exercise (HL-RE). However, very little is known about hamstring muscle thickness, stiffness, and strength after BFR-RE. This study aimed to compare the effects of 6 weeks of BFR-RE and HL-RE on hamstring muscle thickness, stiffness, and strength. Twenty-nine recreationally trained men were pair matched and randomly assigned to the BFR-RE (n = 15) and HL-RE (n = 14) groups. The BFR-RE groups performed bilateral lying leg curl exercise (30-15-15-15 reps, 30-second rest between the sets, 30% 1RM) with BFR cuffs (60% of limb occlusion pressure), whereas HL-RE performed the same exercise (3 × 12 reps, 90-second rest between the sets, 70% 1RM) without BFR cuffs. Hamstring muscle thickness, muscle stiffness, isokinetic muscle strength, and 1RM were assessed at baseline and follow-up after completing a 6-week resistance exercise program (3× a week). Hamstring muscle thickness was assessed by ultrasonography, whereas muscle stiffness was evaluated by shear wave elastography. Isokinetic dynamometry and a 1RM strength test were used to determine muscular strength before and after the exercise program. Statistical significance was set at p < 0.05. No significant effect was found for hamstring muscle strength, thickness, and stiffness for group and group × time interaction, and only a significant main effect of time (p < 0.001) was observed for all outcomes. Both groups experienced significant improvements for all outcomes from baseline to follow-up without any between-group differences. In conclusion, results revealed that BFR-RE can provide similar hamstring muscle strength, thickness, and stiffness compared with HL-RE.

The aim of this study was to investigate the relationship between 60m sprint results and reaction times in athletes who took part in the World Indoor Athletics Championships. The reaction times and 60m sprint results were compiled for 483 sprinters (253 male, 230 female) who performed 60m sprint event. Corresponding data were obtained from archives of the official website of the International Association of Athletics Federation (IAAF). The relationship between reaction time and 60m sprint results were calculated using Pearson correlation coefficient. Additionally, the Independent Samples T-Test was used to compare athletes’ reaction times and 60m sprint results. Positive moderate correlation was found between mean values of all 60m sprint results and reaction times, which were analyzed together in all categories (r=.436, p<0.01). Moreover, significant differences were also found between male and female finalists based on the 60m sprint times and reaction times respectively (t=-27.98, p<0.01; t=-3.26, p<0.01). As a result, it can be concluded that reaction time has great importance on 60 m performance. The best reaction time is related to the higher performance of 60m sprint in both male and female athletes. Moreover, this is also similar for round 1, semifinal and final categories. Coaches and athletes may consider improving reaction time to achieve better 60m performance.

The study’s purposes were to examine the associations of training load parameters with locomotor demand and puberty status in elite young soccer players and to predict the percentage of changes in their performance ability with adjustments to the training load parameters, using multivariate regression analysis, while considering PHV and maturity offset. Seventeen male players (15–16 years old) participated in this study. Anthropometrics, body composition, maximal oxygen consumption (VO_2max), and puberty status (for calculating PHV) and maturity offset were assessed. The results demonstrated substantial differences between the PHV, VO_2max, and load parameters (acute and chronic workload (CWL)) over a soccer season. A substantial relationship existed between the workload parameters (VO_2max, CWL, and training monotony (TM)) and maturity offset. All of the variables, except for training strain, demonstrated significant variances in relation to the differences between the first and second halves (p < 0.05). Aerobic performance can be estimated using the CWL, TM, and maturity offset values (R² = 0.46). On the contrary, aerobic power performance can be explained using the acute:chronic workload, TM, and PHV values (R² = 0.40). In conclusion, the biological maturity state of young soccer players has a substantial impact on their functional potential. Variations in accumulated load contribute significantly to aerobic resistance, whereas weight and height contribute significantly to sprint and vertical-jump performance, respectively.

This study investigated the effect of limb occlusion pressure (LOP) position on exercise performance, cardiovascular responses, and perceptual experiences during seated bilateral leg extensions with and without blood flow restriction (BFR). Thirty resistance-trained males (age: 22 ± 2 years; weight: 74.4 ± 13.6 kg; height: 177.4 ± 6.4 cm; BMI: 23.5 ± 3.3 kg/m²) participated. Each performed exercise to failure (4 sets, 30% 1RM, 1 min rest) in three conditions: Supine LOP-BFR, Seated LOP-BFR, and no-BFR. BFR was applied at 60% LOP. Significant interaction effects were found for RPE (p = 0.021, d = 0.76), RPD (p < 0.01, d = 1.72), and DOMS (p < 0.01, d = 2.28). Statistically significant fewer repetitions were completed in Supine LOP-BFR vs. no-BFR (p < 0.01, d = 0.5), Seated LOP-BFR vs. no-BFR (p < 0.01, d = 1.0), and Seated LOP-BFR vs. Supine LOP-BFR (p < 0.01, d = 0.6). RPE was higher in Seated LOP-BFR vs. no-BFR (p < 0.01, d = 0.52). RPD was higher in Supine LOP-BFR vs. no-BFR (p < 0.01, d = 0.62) and Seated LOP-BFR vs. no-BFR (p < 0.01, d = 1.25). DOMS was higher in Supine LOP-BFR vs. no-BFR (p < 0.01, d = 0.77) and Seated LOP-BFR vs. no-BFR (p < 0.01, d = 3.52). Seated LOP-BFR increased perceptual demands and reduced repetitions compared to Supine LOP-BFR. Both LOP-BFR conditions reduced repetitions compared to no-BFR without affecting cardiovascular measures.

This study investigated the effect of bodyweight squat (BWS) with blood flow restriction (BFR) exercise on sprint and jump performance in collegiate male soccer players. Twenty-four male collegiate soccer players (age: 19.3±1.0 years; height: 178.8±5.8 cm; body mass: 73.5±10.7 kg) were randomly divided equally into BFR or control groups. The BFR group performed BWS with BFR, while the Control group performed BWS without BFR 3x/week for eight weeks on nonconsecutive days. Both groups performed BWS for 30-15-15-15 repetitions with 30-second rest between sets (with continuous BFR pressure between sets). Limb occlusion pressure (LOP) was measured in a supine position after 10 min of passive rest by the automated device. Progressive overload was achieved by increasing LOP % weekly. The pressure was set at 60% LOP for the first four weeks and then was increased to 70% LOP for weeks 5 and 6 and then to 80% LOP for weeks 7 and 8. Countermovement jump (CMJ) and 30m sprint performance were assessed before and after the exercise program. No statistically significant differences between groups were identified. Both groups significantly increased sprint and CMJ performance (p

During breaks or playing period changes, players’ accumulated workload, physiological alterations, body composition factors, sleep, and health-related qualities can factor into soccer performance. This research examined the impact of prolonged pauses, including breaks due to the 2022 FIFA World Cup and an earthquake tragedy, on running displacements and ball in-play duration during the 2022/23 Turkish Super League season. The secondary purpose was to determine the relationship between performance metrics and competition outcomes (i.e., wins, losses, or draws). 550 players from 19 Turkish Super League teams were included. Performance metrics such as running speed, accelerations/number of speed actions, total field coverage, and match outcomes (i.e., win, lose, or draw) were analyzed before and after significant pauses in play. We also explored correlations between running speed, number of speed actions, match duration, and total distance covered to understand their influence on soccer performance. Significant differences existed in performance metrics between periods, with higher total displacement and running observed after the World Cup (p < 0.05). Additionally, teams exhibiting more static behavior during matches were likelier to lose points, while those running at higher speeds (p = 0.007) and acceleration (p = 0.008) had a higher winning probability. The findings provide valuable insights into the factors affecting success or failure in soccer matches and have implications for training and preparation strategies in professional soccer. In addition, findings illustrate how breaks influence performance metrics and highlight the challenges coaches face in maintaining player readiness during unplanned pauses. This suggests minimizing such disruptions to support optimal training and preparation strategies in professional soccer.