Tsoukos, A, Veligekas, P, Brown, LE, Terzis, G, and Bogdanis, GC. Delayed effects of a low-volume, power-type resistance exercise session on explosive performance. J Strength Cond Res 32(3): 643-650, 2018-This study examined the delayed effects of a power-type training session on explosive performance. Seventeen well-trained male power and team sport athletes (age: 22.7 ± 5.5 years, height: 181 ± 8 cm, body mass: 80.7 ± 8.6 kg, body fat: 9.2 ± 1.7%, 1 repetition maximum (1RM) half-squat: 163 ± 29 kg) performed 4 sessions (2 experimental and 2 control) 1 week apart in a randomized and counterbalanced order. Explosive performance was assessed before, 24 and 48 hours after a low-volume, power-type training session (5 × 4 jump squats at 40% 1RM with 3 minutes rest), as well as before and after 24 and 48 hours of rest (control). Dependent variables were as follows: countermovement jump (CMJ), reactive strength index (RSI) during a drop jump, leg press maximum isometric force, and rate of force development (RFD) at 3 time windows: 0-100, 0-200, and 0-300 milliseconds. Analysis of variance revealed no changes in the control conditions. In contrast after training, CMJ was improved by 5.1 ± 1.0% and 3.0 ± 1.0% at 24 and 48 hours, respectively, compared with baseline. The RSI improved by 10.7 ± 2.1% only at 24 hours. The RFD increased at all time windows at 24 hours (range of improvement: 9.7 ± 3.4% to 18.3 ± 4.1%, p < 0.01). However, at 48 hours, improvement was only seen in RFD0-100 (9.8 ± 3.1%, p < 0.01). These findings suggest that a low-volume, power-type training session results in delayed enhancement of explosive muscle performance, which is greatest at 24 hours after the activity. Athletes are advised to perform power-type training 1 day before competition or a high-quality training session to improve their performances.

This study investigated the effects of muscle action type during conditioning activity (half-squat) on subsequent vertical jump performance. Fourteen track and field athletes (relative half-squat of 2.3 ± 0.3 times their body weight) completed 4 main trials in a randomized and counterbalanced order 5-7 days apart: (a) concentric (CON) half-squats: 7.5 ± 1.2 repetitions against 90% of 1 repetition maximum (1RM), (b) eccentric (ECC) half-squats: 9.3 ± 1.5 repetitions against 70% of 1RM, and (c) 3 sets of 3-second maximal isometric (ISO) half-squats, (d) a control (CTRL) trial, where subjects rested for 10 minutes. The number of repetitions in CON and ECC was adjusted so that the impulse of the vertical ground reaction force was similar to ISO. Countermovement vertical jump (CMJ) performance was evaluated for 21 minutes after each main trial. Countermovement vertical jump performance in ISO was higher than CTRL from the second to the 10th minute of recovery, whereas CMJ performance in ECC was higher than CTRL from the sixth and 10th minute of recovery. Analysis of the peak individual responses revealed an increase in CMJ performance compared with baseline only in ISO (3.0 ± 1.2%; p = 0.045), whereas no significant increases were observed in ECC and CON. Peak CMJ performance for all subjects in ISO and ECC was achieved within 2-10 minutes after the conditioning muscle actions. Isometric were more effective than CON and ECC muscle actions in increasing explosive leg performance when the impulse of the ground reaction force of the conditioning exercise was equated.

Tsoukos, A, Brown, LE, Terzis, G, Veligekas, P, and Bogdanis, GC. Potentiation of bench press throw performance using a heavy load and velocity-based repetition control. J Strength Cond Res 35(2S): S72–S79, 2021—The acute effects of heavy load bench press exercise on subsequent bench press throw (BPT) performance and surface electromyographic (sEMG) activity were examined using movement velocity control. Eleven resistance-trained men completed 3 conditions in randomized and counterbalanced order. In 2 conditions, bench press was performed as fast as possible against a load of 80% of 1 repetition maximum, until mean velocity dropped to 90% (C90) or 70% (C70) of the fastest repetition. In the control condition, no bench press was performed. Single maximal BPT efforts were performed in all conditions after warm-up and throughout the 12 minutes of subsequent recovery. Mean propulsive velocity (MPV), peak velocity (PV), and sEMG activity of the prime mover muscles were measured during the BPT efforts. The total number of repetitions and volume load during bench press were significantly greater in C70 compared with C90 (6.5 ± 1.9 vs. 3.4 ± 0.9 repetitions and 557.8 ± 177.8 vs. 293.8 ± 95.7 kg, p < 0.01). In C90, MPV was increased 5.3–7.4% (p < 0.01) for a prolonged period (4–12 minutes), while in C70, MPV increased only at 10 minutes (+5.9%, p < 0.01) and 12 minutes (+4.3%, p < 0.01). Peak velocity was improved only in the C90 at 8–12th min by 3.6–4.7% (p ≤ 0.05). Surface electromyographic activity of the pectoralis major muscle was significantly greater than baseline at 10 minutes of recovery only in the C90 (p < 0.01). Performance gains may be optimized by taking into account the individual fatigue profiles, allowing a percentage drop of only 10% in movement velocity during the conditioning bench press exercise.

This study examined the acute effects of the bench press exercise with low and moderate loads as well as with two predetermined movement velocity loss percentages on bench press throw performance and surface electromyographic (sEMG) activity. Ten trained men completed 5 main trials in randomized and counterbalanced order one week apart. Mean propulsive velocity (MPV), peak velocity (PV) and sEMG activity of prime movers were evaluated before and periodically for 12 minutes of recovery under five conditions: using loads of 40 or 60% of 1 RM, until mean velocity dropped to 90 or 70%, as well as a control condition (CTRL). MPV and PV were increased 4-12 min into recovery by 4.5-6.8% only after the 60%1RM condition during which velocity dropped to 90% and total exercise volume was the lowest of all conditions (p < 0.01, Hedges’ g = 0.8-1.7). When peak individual responses were calculated irrespective of time, MPV was increased by 9.2 ± 4.4 (p < 0.001, Hedges’ g = 1.0) and 6.1 ± 3.6% (p < 0.001, Hedges’ g = 0.7) under the two conditions with the lowest total exercise volume irrespective of the load, i.e. under the conditions of 40 and 60% 1RM where velocity was allowed to drop to 90%. sEMG activity of the triceps was significantly greater when peak individual responses were taken into account only under the 60%1RM condition when velocity dropped to 90% (p < 0.05, Hedges’ g = 0.4). This study showed that potentiation may be maximized by taking into account individual fatigue profiles using velocity-based training.

This study compared the effects of unilateral and bilateral plyometric training on single and double-leg jumping performance, maximal strength and rate of force development (RFD). Fifteen moderately trained subjects were randomly assigned to either a unilateral (U, n=7) or bilateral group (B, n=8). Both groups performed maximal effort plyometric leg exercises two times per week for 6 weeks. The B group performed all exercises with both legs, while the U group performed half the repetitions with each leg, so that total exercise volume was the same. Jumping performance was assessed by countermovement jumps (CMJ) and drop jumps (DJ), while maximal isometric leg press strength and RFD were measured before and after training for each leg separately and both legs together. CMJ improvement with both legs was not significantly different between U (12.1±7.2%) and B (11.0±5.5%) groups. However, the sum of right and left leg CMJ only improved in the U group (19.0±7.1%, p<0.001) and was unchanged in the B group (3.4±8.4%, p=0.80). Maximal isometric leg press force with both legs was increased similarly between groups (B: 20.1±6.5%, U: 19.9±6.2%). However, the sum of right and left leg maximal force increased more in U compared to B group (23.8±9.1% vs. 11.9±6.2%, p=0.009, respectively). Similarly, the sum of right and left leg RFD0-50 and RFD0-100 were improved only in the U group (34-36%, p<0.01). Unilateral plyometric training was more effective at increasing both single and double-leg jumping performance, isometric leg press maximal force and RFD when compared to bilateral training.