Effects of exercise intensity on perceived exertionduring multiple sets of bench press to volitional failure

Abstract

Objectives:The purpose of this study was to investigate the effects of intensity on rating of perceived exertion (RPE) during multiple sets to volitional failure in bench press exercise. Design and Methods: Thirteen moderately resistance trained men performed 2 experimental sessions in random order: 3 sets to failure in bench press with 1 minute rest at an intensity of 50% and 70% of 1 repetition maximum (1RM). RPE was measured using the OMNI scale after each set. Readiness to Invest in Physical (RTIPE) and Mental (RTIME) Effort were assessed before each set. Results: Repetitions to failure (46.46 ± 9.43 vs 26.62 ± 8.19; P<0.001) and total weight lifted (2044.31 ± 414.5 vs 1650.15 ± 507.83 kg; P<0.001) were greater at 50% when compared to the 70% 1RM condition. There were no differences in RPE, RTIPE, RTIME and heart rate across conditions. Conclusions: These results indicate that when repetitions are done to volitional failure, monitoring RPE is not a useful technique in regulating intensity during resistance training.(Journal of Trainology 2014;3:41-46)

Efeito da velocidade de contração na fase excêntrica sobre a percepção subjetiva de esforço

“…Such condition is related to a momentary increase in difficulty of execution and exercise intensity, as well as, possibly, to a physiological increase in lactate, phosphocreatine depletion and decreased blood pH, which can induce a greater RPE during strength exercises 5,11 . As a result of these physiological changes, there may be a reduction in the number of repetitions throughout the sets 16 , which was also verified in our study, thus corroborating our initial hypothesis.…”

“…On the other hand, when bench press was executed until concentric failure at 50% or 70% of 1RM, no difference in RPE was observed, despite the greater total weight lifted in the 50% 1RM condition16. In a study conducted by Silva et al 16 , cadence was free, i.e., not controlled by the researchers. In their turn, while investigating the influence of cadence on RPE, Diniz et al 12 showed that the participants who performed the experimental protocol at a slow movement velocity (2 seconds of concentric action for 4 seconds of eccentric action) presented a higher RPE, both per set and total, and a lower volume of total In the present study, the participants who performed the protocols at moderate (2020) and free movement velocities presented a lower RPE throughout the sets, as well as and higher volumes of repetition, corroborating the findings of Day et al 16 , according to which the group that executed the protocol with less intensity performed a greater number of repetitions and presented a lower RPE.…”

Ability to predict repetitions to momentary failure is not perfectly accurate, though improves with resistance training experience

“…As we have recently noted in several papers ( Steele, 2014 ; Steele et al, 2017b ; Steele et al, 2017a ), and as have others, differentiation between perceptions of effort and discomfort are important ( Abbiss et al, 2015 ; Marcora, 2009 ; Smirnaul, 2012 ) particularly within RT ( Steele, 2014 ; Steele et al, 2017b ). In studies using traditional rating of perceived exertion scales higher ratings are given, despite conditions being controlled by supposedly training to MF, with lower loads for lower body exercise ( Shimano et al, 2006 ), as set volume increases ( Silva et al, 2014 ), with increased volume-load ( Pritchett et al, 2009 ), and with increased work rate ( Hiscock et al, 2016 ; Hiscock, Dawson & Peeling, 2015 ) supporting that participants may have expressed their feelings of increasing discomfort ( Steele, 2014 ; Steele et al, 2017b ; Steele et al, 2017a ).…”

Clarity in reporting terminology and definitions of set endpoints in resistance training

“…Thus, we can only assume that the participants were unclear as to how to report their perception of effort. Increasing ratings of effort were, however, given with conditions known anecdotally to produce greater acute discomfort, such as lower load lower body exercise, as set volumes increased, with increased work volume, and with increased work rate . This suggests participants were more likely to express their feelings of increasing discomfort .…”

“…Differentiation between perceptions of effort and discomfort have been highlighted recently as important, particularly in RT, for good reason. A number of studies measuring rating of perceived exertion (RPE) using a Borg CR10 scale (where a value of 10 indicates maximal effort) reported that participants exercised to MF and received verbal encouragement to ensure adequate motivation and effort. In this case, each trial, irrespective of exercise, load, or training status, should have resulted in a maximal value for effort, because people were exercising to MF.…”