The stretching protocols improve hamstrings flexibility immediately, but after exercise hamstrings peak torque is diminished in the SS+PNF but not in the SS+Taping group. This means that SS+Taping can prevent negative results from exercise, which may prevent muscle injury.

Chen, CH, Chiu, CH, Tseng, WC, Wu, CY, Su, HH, Chang, CK, and Ye, X. Acute effects of combining dynamic stretching and vibration foam rolling warm-up on lower-limb muscle performance and functions in female handball players. J Strength Cond Res 37(6): 1277–1283, 2023—The purpose of this study was to compare the acute effects of 3 warm-up protocols on knee flexor and extensor muscles performance in elite female collegiate handball players. Ten female handball players with poor hamstring flexibility completed 3 randomly sequenced experimental visits. During each visit, a different warm-up protocol (general running warm-up [GW], dynamic stretching [DS], or DS combined with vibration foam rolling [DS + VR]) was delivered before the subsequent tests: quadriceps and hamstring muscle stiffness, knee extension and flexion range of motion (ROM), knee joint position sense, knee extension and flexion isokinetic strength with hamstring-quadriceps strength ratio, and muscle endurance during fatiguing exercise. Relative to the GW, the DS + VR protocol resulted in significantly greater knee flexion ROM (mean ± SD: DS + VR = 79.4° ± 7.7°; GW = 69.3° ± 9.6°) and lower hamstring muscle stiffness (DS + VR = 253.33 ± 36.20 N·m−1; GW = 292.89 ± 24.28 N·m−1). In addition, the DS + VR protocol also yielded greater hamstring muscle endurance than the other 2 protocols did (fatigue percentage: DS + VR = 30.24% ± 10.84%; GW = 41.40% ± 8.98%; DS = 42.22% ± 9.42%). Therefore, the results of this experiment suggest that it can be more beneficial for the female handball players to warm-up with the DS + VR, rather than the GW and DS protocols.

The purpose of this study was to determine whether transcranial direct current stimulation (tDCS) can improve countermovement jump performance, fatigue index and alleviate the speed decline during repeated shuttle sprints in trained basketball players. Thirteen trained basketball players were divided into the tDCS trial and sham trial by the random crossover design. The tDCS trial was stimulated with 2-mA current in the M1 area in the middle of the top of the head for 20 min. For the sham trial, the current was turned off after 5 s, stopping the electrical stimulation. After warming up, the players underwent countermovement jump test, weighted countermovement jump test and then performed 40 × 15-m sprints with with a 1:4 exercise: rest ratio. The jump height, sprinting time, fatigue index, heart rate and rating of perceived exertion (RPE) were analyzed by paired-sample t-test, when significance was discovered by two-way repeated measures analysis of variance. The study results revealed that the tDCS trial significantly increase the countermovement jump performance (p = 0.04), decrease the sprinting time (p = 0.016), and had improved fatigue index during the sprinting process (p = 0.009). However, the heart rate and RPE during sprinting were nonsignificantly different between the trials. This study has identified that tDCS can decrease the speed decline, fatigue index during sprinting and increase countermovement jump performance without affecting heart rate or the rating of perceived exertion.

The effect of asymmetry on flexibility and jump in taekwondo athletes and the influence of vibration foam rolling on asymmetry and frequency speed of kick test has not been examined. This study examined the effects of three warm-up protocols on subsequent sports performance in elite male taekwondo athletes. Fifteen elite male taekwondo athletes (20.63 ± 1.18 years) completed three warm-up protocols in a randomized order: general warm-up [GW], GW with vibration foam rolling [GW + VR], and GW with double VR for the weaker leg [GW + double VR]), was delivered before the subsequent tests: flexibility, single-leg countermovement jump (CMJ), 505 agility, hexagon test, and multiple frequency speed of kick tests (FSKTs). Relative to GW, the GW + VR significantly improved the hexagon test (GW + VR = 11.60 ± 1.01 s; GW = 12.80 ± 1.58 s). In addition, the GW + VR and GW + double VR yielded greater kick numbers in FSKT 5 (GW + VR = 21.13 ± 1.96 reps; GW + double VR = 20.93 ± 1.67 reps; GW = 19.27 ± 1.62 reps) and a higher kick decrement index (GW + VR = 5.45 ± 2.57%; GW + double VR = 5.88 ± 3.22%; GW = 9.54 ± 5.00%). However, the GW + VR and GW + double VR did not significantly improve the flexibility and CMJ asymmetry performance. The GW + VR is more beneficial for warming up than the GW is among male collegiate taekwondo athletes.

The purpose of this investigation was to examine whether adding a set of hamstring resistance exercise or dynamic stretching to a regular running-based warm-up before a bout of repeated sprints provides protective effects against the sprinting-induced muscle damage. Twelve elite tennis players participated in this study. After the familiarization, subjects completed 3 separate randomly sequenced experimental visits, during which 3 different warm-up interventions were performed before the muscle-damaging protocol (12 sets of 30-m maximal repeated sprints): 5 minutes of running (control); control with single leg slide curl (SLC); and control with active hamstring stretching (AHS). Before, immediately (POST0), 1 day (POST1), and 2 days after (POST2) the sprints, hip flexion passive range of motion, hamstring muscle thickness and pennation angle, muscle stiffness, and knee flexion concentric peak torque were measured. Repeated sprints have induced muscle damage in all 3 visits. For AHS, the muscle thickness and stiffness values at POST2 were significantly lower than those of other 2 protocols. In addition, the decrements of concentric strength at POST0, POST1, and POST2 for AHS were also significantly less than those of control and SLC. Therefore, adding a set of dynamic hamstrings stretching to a regular warm-up protocol before repeated sprints has protective effect on the sprinting-induced muscle damage. Athletes whose competitions are densely scheduled (e.g., tennis player in a tournament) may take advantage of this strategy to facilitate muscle recovery from the potential muscle damage, thus, to get maximal recovery for the subsequent competitions.