This study aimed to perform a systematic review and meta-analysis on the efficacy of upper-body PAPE conditioning activities. Data suggest that several upper-body conditioning activities can be used to acutely improve upper-body performance. Findings varied between studies, at times because of differences in experimental designs and procedures, as discussed in later sections.
Bench Press Variation Conditioning Activities
As highlighted in the meta-analysis, the bench press with loads of ≥ 80%1RM can be an effective conditioning activity to elicit improvements in subsequent power output in the BBT at 30–40%1RM [25, 27, 35, 38, 40, 41]. Only one study [35] reported a marginally detrimental effect on BBT power output. Peak power output was typically observed between 8 and 12 min post-conditioning activity; however, this varied because of the different timepoints considered. Where performance at multiple timepoints was considered, three studies reported a peak in BBT power output after 8 min rest [25, 38, 41], whilst one study reported a peak at 12 min [40]. All of the above studies implemented a bench press protocol of ≥ 80%1RM, which could suggest that a heavy load bench press conditioning activity requires a considerable recovery duration to induce PAPE. It should be noted, however, that loads were rarely directly compared in the literature. Liossis et al. [41] found 4 min was optimal recovery following bench press at 65%1RM, whilst 8 min was considered optimal for the 85%1RM load. This again highlights the trade-off between fatigue and PAPE. Similarly, 7 min following a bench press protocol at 90%1RM was sufficient recovery to observe a significant increase in concentric-only bench press power output [29]. Coaches and practitioners may wish to use the bench press as a conditioning activity to evoke PAPE in subsequent BBT; however, as noted by Seitz and Haff [4], greater recovery durations may be needed where high loads are used.
The only study that utilised a heavy bench press protocol on subsequent bench press power output found no significant improvements [31]. However, the 3 × 3 protocol of 85%1RM in that study was described as ‘reps to failure’, which is perhaps not synonymous with producing efforts of maximum power output. Further research is needed to analyse the effects of prior heavy bench press on subsequent bench press power output.
Bench press also failed to elicit improvements in handball throwing velocity [55]. Firstly, the biomechanical differences between the conditioning activity and the performance test are apparent [4], which may suggest the bench press may not transfer to acute task-specific performance improvements. A recent review found the greatest PAPE was typically observed ≥ 5 min following high-to-moderate intensity conditioning activities [4]. It could, therefore, also be plausible that the single measurement at 4 min [55] may not have been sufficient recovery to reduce fatigue from the multiple repetitions of 90%1RM bench press. The same limitations applied to a study by Martinez-Garcia et al. [46], who found no significant improvements in overhead handball throwing velocity following a standing chest press with variable resistance, with even shorter initial recovery durations. Markovic et al. [33] also found bench press produced non-significant differences in throwing performance 3 min following the conditioning activity, where the medicine ball load (0.55-kg) was similar to that of a handball. However, the latter study did find a significant improvement (p = 0.001; 8.3%) in throwing distance at the same rest period, with a heavier (4-kg) medicine ball. The bench press may have potential in improving sport-specific performance such as throwing, though this may be load specific [33]. The monitoring of only one timepoint in both studies could mask potential PAPE effects that manifest at greater recovery durations, which may mislead the coach or practitioner on the efficacy of such conditioning activities. However, it is worth noting that several testing intervals may also negatively affect subsequent performance due to fatigue, therefore requiring careful consideration.
Only a single study [35] explored the use of concentric-only bench press as a conditioning activity to improve BBT power output, evidencing potential effectiveness. Similarly, only one study explored the use of concentric-only bench press on subsequent plyometric activity [39], finding it may not be an effective method to acutely improve performance in the plyometric push-up. Post-activation performance enhancement was monitored at only one timepoint following the conditioning activities in the two studies [35, 39], 12 min and 1 min, respectively. Again, it is conceivable that performance improvement could manifest at later timepoints, when considering the time course of PAPE is thought to last for several minutes [4]. In the initial minutes following the conditioning activity, other mechanisms such as PAP may be the basis of performance improvement [5], suggesting the 1 min recovery period in the study by Bodden and colleagues is inappropriate in relation to PAPE. This is especially true when reflecting on the incremental high-volume protocol involved [39]. The lack of studies exploring the efficacy of concentric-only bench press to induce PAPE suggests the evidence is unclear.
The evidence presented in this review suggests that eccentric-only bench press does not induce a PAPE effect in BBT power output [25, 35]. Both studies reported no significant differences as a result of the conditioning activity. Though high loads have been demonstrated to induce PAPE throughout this review, the supramaximal nature (120%1RM) of the conditioning activity in the study by Ulrich and Parstorfer [25] may have induced too much fatigue, thus suppressing PAPE. This is despite the lower number of overall reps (1 × 3) performed compared with bench press PAPE studies. Esformes et al. [35] used a lighter load, equivalent to 3RM, and found only a very marginal increase (0.8%) in power output. Therefore, the PAPE-inducing capability of the eccentric-only bench press on the BBT is not currently supported by the literature.
The two studies that included an isometric variation presented conflicted findings [28, 35]. Tsolakis et al. [28] found no significant differences in BBT power output following isometric bench press. Further analysis revealed that the female athletes possessed relative strength levels (bench press 1RM as a percentage of body mass) of 0.62, noticeably lower than the 1.01 achieved by the male athletes in the same study. As strength level is a modulating factor of the PAPE response [4], the large differences in strength levels could explain the apparent lack of performance improvement. Specifically, stronger athletes are able to achieve greater levels of PAPE (ES = 0.41), compared with their weaker counterparts (ES = 0.32) [4]. It has been suggested that an increased level of strength may make an individual more resistant to fatigue following a conditioning activity, thus responding more favourably than weaker athletes [4].
In contrast, Esformes et al. [35] did identify significant improvements in subsequent BBT power output, where participants possessed overall relative strength levels (bench press 1RM as a percentage of body mass) of 1.1 in the bench press. Additionally, the latter study included only one maximal voluntary contraction, whereas Tsolakis et al. [28] included three. Differing protocols and the ensuing fatigue may contribute to the varied results, though the overall contraction time was similar in both studies. The lack of research makes it difficult to infer the effectiveness of an isometric bench press conditioning activity in inducing an acute performance benefit in the BBT. Efficacy may be contingent on athlete strength levels, and by association, sex.
West et al. [27] reported increases in BBT power output, 8 min following a 3 × 3 BBT conditioning activity at 30%1RM. In contrast, separate trials of 1 × 5 BBT at various loads ≥ 50%1RM did not influence BBT power output after 4 min rest [34]. The disparity between the two studies may be explained by the increased recovery time in the former study. A single set of 3 repetitions of BBT at 30% did not elicit any differences in subsequent BBT performance [54]. Interestingly, in the same study, a contrast protocol of 1 × 3 BBT at 30%1RM, followed by 1 × 5 at 60%1RM load did produce an improvement in power output at 3 min (8.7%) and 5 min (10.4%), respectively. The differences at the two timepoints again support the notion of optimal post-intervention timing. The evidence suggests that the BBT as part of a resistance exercise contrast or complex set may be a promising conditioning method to induce PAPE, and thus, improve subsequent performance in the same activity. However, as is a common theme throughout, more research is required to confirm this.
Further research could explore whether bench press variations can acutely influence task-specific or sporting performance. This would enable practitioners and coaches to determine whether it has appropriate inclusion as a pre-competition warm-up conditioning activity for athletes. Though, as previously discussed, biomechanical specificity and logistical issues mean more sport-specific PAPE conditioning activities could be better alternatives for athletes.
Sport-Specific Conditioning Activities
Select studies explored the use of movement-specific combinations that involve the sporting action as the conditioning activity and performance test, thus greater specificity to sporting performance. These complexes can be used more widely for athletes outside of a weight room or laboratory, for example, within the constraints of the competition warm-up environment and are described in the sections below.
Modified Implement Throw Conditioning Activities
The current data suggest that warming up with overweight implements could potentially improve subsequent throwing for distance performance; however, the previous literature suggests there may be a limit to performance benefits at increased loads [26, 37, 42]. A plausible reason for the improvement could be due to the conditioning activities and the performance tests being either identical or at least sharing biomechanical similarities [4]. It is worth noting that although the participants were trained in their respective throwing disciplines, strength levels in the studies varied [26, 37], whilst one study did not report this information [42]. All studies shared a 3 min recovery period between the cessation of the conditioning activity, and the performance measure. Whilst this suggests that a 3 min period may be sufficient to elicit a performance improvement following a throwing conditioning activity, the time course of PAPE is purported to last several minutes [4]. Thus, the lack of monitoring at several timepoints may underestimate a ‘peak’ in the PAPE effect. Though, it is again worth noting the potential negative performance effects that could arise from excessive testing intervals. Nevertheless, on current evidence, warm-up throws with a marginally overweight implement compared with the competition standard seem to be an effective method of improving competition throwing performance where increased distance is the primary goal. Therefore, throwing coaches could consider adopting this well-practiced strategy either as a pre-competition conditioning activity or in-between throws in training, once individual athlete responsiveness has been established. In contrast, the use of a heavy cricket ball, and indeed a lighter cricket ball, did not yield any performance improvement in cricket bowling speed and accuracy [50]. Again, the latter study included a short recovery duration of 3 min between the conditioning activity and the subsequent performance test. Likewise, participant strength levels were not reported.
Swing-Specific Conditioning Activities in Ball Striking Sports
Five studies were included in the review pertaining to ball striking sports [36,43,49,51,52]. Bliss et al. [49] reported improvements in speed and distance in the golf swing, 1 min following prior swings with light and heavy implements, compared with a control trial. The study by Bliss et al. [49], and indeed all of the swing-specific sports included in the review, comprised PAPE conditioning activities that shared clear biomechanical specificity to the performance test in terms of the movement pattern. Bat swing-specific isometric contractions of a 5-s duration seemingly induce a PAPE effect on subsequent swing velocity [43, 51]. Gilmore et al. [43] demonstrated a PAPE effect following 3 × 5 bat swing-specific isometric contractions, in a group of athletes that are not considered to be the strongest, whereas Higuchi et al. [51] did not report strength characteristics. Interestingly, the latter study showed an ~ 1.3% increase in swing velocity after just 1 min of rest post-conditioning activity. The evidence on the efficacy of weighted swings would suggest it does not improve, and in some cases, may even be detrimental to subsequent swing velocity [36, 51, 52]. Where Bliss et al. [49] reported improvements post ‘heavy’ swings, this was actually of a similar mass to that of a standard golf club, and was part of a protocol of contrasting implements. Montoya et al. [36] reported an increase (3.3%) in swing velocity after lighter bat swings, compared with a standard bat. All studies pertaining to swing-specific conditioning activities in ball striking sports had administered the initial post-performance test within 1 min of the conditioning activity. Considering the proposed time course of PAPE and the possible coexistence of PAP and PAPE [5, 16], any performance improvements may not necessarily be solely attributed to PAPE. Despite the small body of work in the area, the use of bat swing-specific conditioning activities in the form of isometric contractions appear to be a useful method for improving subsequent swing velocity. This method has been applied in baseball and softball, though it may offer a novel method for the coach and practitioner across other sports that require upper body distal point velocity, such as throwing or punching. The use of lighter weighted swings or contrasting light-heavy swings may be useful in improving subsequent swing-specific performance [36, 49]; however, more research should explore the efficacy of this method.
Cable Pulley Conditioning Activities
Three studies explored the use of a cable pulley-type mechanism as a ‘sport-specific’ PAPE conditioning activity. Asencio et al. [55] did not find any improvements in handball throwing velocity after eccentric conical pulley activity, with the authors stating this was possibly due to the short recovery time of 4 min. Hancock et al. [44] implemented a longer recovery duration of 6 min following the swimming-specific mode and found an ~ 0.8% reduction in swim sprint time, corresponding to just under a 1-s improvement. Cuenca-Fernandez et al. [48] also administered a 6 min recovery period to national-level swimmers post-dynamic stretching and 1 × 3 cable pull overs at 85% of 1RM. Compared with a control trial of a swimming-only warm-up, rate of force development and stroke rate improved in the 15-m front crawl. Interestingly, the conditioning activity produced a negative effect on variables such as velocity and distance covered. More research is needed to understand the potential benefits of the cable pulley or similar resistance, as a PAPE-inducing conditioning activity.
Elastic Resistance Conditioning Activities
Only one study was included in the review that explored the efficacy of a PAPE conditioning activity with elastic resistance [45]. Increases in the thrust and speed of international and national-level swimmers’ 25-m front crawl performance was reported following 2 × 5 elasticated pulls performed 8 min prior. The inclusion of only one study does perhaps show an under-utilisation of elastic resistance to induce PAPE. Elastic resistance has successfully induced a PAPE effect in combat-specific actions [56, 57]; however, because of the lower-body elements of the conditioning activities, the relevant studies were not included in this review. Therefore, future research should further explore the efficacy of upper-body elastic resistance activity in inducing PAPE in a variety of sports.
Bodyweight Conditioning Activities
Sarramian et al. [53] compared the effects of a swimming warm-up inclusive of 1 × 3 pull-ups at 3RM, to a control trial of just a swimming warm-up. The findings showed the addition of the pull-up conditioning activity did not improve 50-m freestyle swim performance to a greater extent than the swimming warm-up, despite the inclusion of individual rest times. The only study to explore the PAPE-inducing effect of the push-up, included a 30-m freestyle swim as the performance test [30]. The authors found no significant improvements compared to a control trial of rest. A number of factors could explain the lack of performance improvement. Firstly, the protocol was reported as a 30-s maximal effort. This conditioning activity may induce levels of fatigue that would suppress any possible PAPE effect. Indeed, the authors reported mean pre-swim blood lactate levels of 3.6 ± 0.9 mmol.l−1 during the push-up trial, compared with 1.9 ± 8 mmol.l−1 at the same point in the control. There is also arguably little biomechanical specificity between the push-up and freestyle swim technique; however, it should be noted that it is not a requirement for the conditioning activity to directly mimic the sporting activity [11]. Lastly, no information on the strength levels of participants was provided by the authors.
Plyometric versions of the push-up have received more focus in the literature. Ulrich and Parstorfer [25] found the plyometric push-up to be an effective conditioning activity to improve subsequent BBT power output by ~ 4.9% after 8 min. Both exercises share similar stretch–shortening cycle principles, whereby a rapid eccentric loading is followed by a rapid concentric push [58]. This again perhaps highlights the importance of biomechanical specificity. Other authors [28] reported only a marginal and non-significant increase in BBT performance, when preceded by a plyometric push-up protocol, comprising the same recovery time implemented by Ulrich and Parstorfer [25]. However, the former study included both female and male participants, with female participants exhibiting considerably lower strength levels, resulting in markedly greater strength levels in the study by Ulrich and Parstorfer [25]. Krzystofik and Wilk [32] found increases in peak power output and bar velocity 4 min post 3 × 5 plyometric push-ups compared with a control trial; however, both variables were weaker than the control trial at 12 min post. Krzystofik and Wilk [32] also reported considerably greater strength levels in their study, compared with that of Tsolakis et al. [28]. As PAPE seemingly manifests in a greater magnitude in stronger athletes [4], this could partly explain the different magnitudes of PAPE observed between the studies. Additionally, Tsolakis et al. [28] instructed participants to complete 15 overall repetitions compared with ten in the study by Ulrich and Parstorfer [25]. Plyometric push-ups performed alongside counter-movement jumps elicited small increases in golf drive speed and distance compared with a control trial [49]. The inclusion of the lower body element, however, makes it difficult to attribute the performance increase to the plyometric push-up.
In summary, it is not yet possible to infer the usefulness of push-ups as a conditioning activity to induce PAPE. However, the findings of three studies [25, 28, 32] suggest that the plyometric variation of the push-up may have potential as a conditioning activity to induce PAPE in the bench press, BBT or golf drive performance.
Combination of Exercise Conditioning Activities
One study included in the review was categorised on its own, due to the combination of many types of activity [47]. Gelen et al. [47] found increases in tennis serve velocity following an upper-body dynamic warm-up, inclusive of movements with the tennis racket. Interestingly, even greater benefits were found following a ‘ballistic 6’ protocol, whereby the tennis athletes performed a combination of upper-body rotational movements with elastic resistance and implement throws. This suggests a conditioning activity inclusive of ballistic movement may induce PAPE, as seen in the previously discussed sport-specific sections. It is, however, difficult to infer which activities are responsible for the performance improvements.