Postactivation Potentiation of Bench Press Throw Performance Using Velocity-Based Conditioning Protocols with Low and Moderate Loads

Abstract

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.

Keywords: EMG activity; mean propulsive velocity; peak velocity; velocity loss.

Figure 1

Schematic representation of the experimental trials. BPT: bench press throw, SWU: Specific Warm-Up.

Figure 2

Mean and peak velocity of the first and last repetitions during the conditioning activity (CA) across the experimental conditions compared with the number of repetitions. Values are presented as mean ± SD. *: p < 0.01 between the first and the last repetition under the 40%_70v condition. #: p < 0.01 between the last repetitions of 40%_90v and 40%_70v. †: p < 0.01 between the first and the last repetition under the 60%_90v condition. ‡: p < 0.01 between the first and the last repetition under the 60%_70v condition. ¤: p < 0.01 between the last repetitions of 60%_90v and 60%_70v. ¥: p < 0.01 difference between the first and the last repetition under the 40%_90v condition.

Figure 3

Time course of changes of mean propulsive velocity (MPV) performance during the bench press throws. Values are expressed as percent changes compared to baseline values. *: p < 0.01 from the corresponding baseline value. #: p < 0.01 from the corresponding value under the control condition. ¥: p < 0.01 from the corresponding value under the 60%_70v condition. ‡: p < 0.05 from the corresponding value under the 40%_70v condition.

Figure 4

Percent change of mean propulsive velocity (MPV) during the bench press throws between baseline (PRE) and the best MPV, irrespective of the time attained during recovery. *: p < 0.01 from the corresponding baseline value. #: p < 0.01 from the corresponding value under the control condition. ¥: p < 0.01 from the corresponding value under the 60%_70v condition. ‡: p < 0.05 from the corresponding value under the 40%_70v condition. CTRL: control condition.

Figure 5

Time course of changes of peak velocity (PV) performance during the bench press throws. Values are expressed as percent changes compared to baseline values. *: p < 0.05 from the corresponding baseline value. #: p < 0.01 from the corresponding value under the control condition. ¥: p < 0.05 from the corresponding value under the 60%_70v condition. ‡: p < 0.01 from the corresponding value under the 40%_70v condition. †: p < 0.01 from the corresponding value under the 40%_90v condition.

Figure 6

Percent change of peak velocity (PV) during the bench press throws between baseline and the highest peak velocity, irrespective of the time achieved during recovery. *: p < 0.01 significantly different from the corresponding baseline value. #: p < 0.05 significantly different from the corresponding value under the control condition. ¥: p < 0.01 significantly different from the corresponding value under the 60%_70v condition. CTRL: control condition