New Approach in Assessing Core Muscle Endurance Using Ratings of Perceived Exertion

Abstract

George, JD, Tolley, JR, Vehrs, PR, Reece, JD, Akay, MF, and Cambridge, EDJ. New approach in assessing core muscle endurance using ratings of perceived exertion. J Strength Cond Res 32(4): 1081-1088, 2018-This study sought to develop regression models to estimate maximal endurance time using data from 4 core muscle endurance tests. Eighty healthy university students (age: 22.7 ± 1.9 years) performed the plank, right side-bridge, left side-bridge, and back extension tests in a random order. Participants were instructed to hold each static position for a maximal endurance time, while maintaining proper form, and then rest for 5 minutes between tests. A test administrator recorded participants' ratings of perceived exertion (RPE; a modified 10-point scale) every 5 seconds. Based on regression analysis, the elapsed time to reach an RPE of 8 (RPE8) exhibited statistical significance (p < 0.0001) and the highest accuracy as compared with lower RPE values. The following univariate regression models were generated to estimate maximal endurance time across the 4 tests: plank (r = 0.94; standard error of estimate [SEE] = 17.6 seconds; n = 77) = 23.9 + (1.110 × RPE8); right side-bridge (r = 0.92; SEE = 11.4 seconds; n = 80) = 18.5 + (1.022 × RPE8); left side-bridge (r = 0.93; SEE = 10.8 seconds; n = 80) = 16.8 + (1.062 × RPE8); and back extension (r = 0.93; SEE = 14.2 seconds; n = 79) = 21.5 + (1.027 × RPE8). These results suggest that submaximal protocols based on elapsed time to reach RPE8 provide strength and conditioning professionals relatively accurate univariate regression equation estimates of maximal core muscle endurance time and offer a viable submaximal alternative to maximal capacity testing when time efficiency, participant safety, or certain educational objectives may be a priority.

Does trunk and hip muscles strength predict performance during a core stability test?

“…Hip extensors are highly active during the bridge test with unilateral knee extension. 34 Therefore, their weakness may predict other parameters related to better performance of this test, such as increased maximal endurance time and lower perceived exertion. 34 This study had some limitations.…”

“…34 Therefore, their weakness may predict other parameters related to better performance of this test, such as increased maximal endurance time and lower perceived exertion. 34 This study had some limitations. First, maximal isometric muscle strength might not be the best measure of trunk and hip muscles' function.…”

Análise eletromiográfica de músculos do tronco e percepção subjetiva de esforço no exercício prancha ventral até a exaustão com diferentes equipamentos instáveis

“…Os indivíduos executaram uma repetição de cada exercício com contração isométrica. Para evitar o efeito da fadiga muscular como fator limitante, foram utilizados cinco minutos de intervalo de descanso entre cada exercício 32,66 .…”

“…Para o exercício PV-SO (Figura 6), os participantes foram instruídos a manter a posição de decúbito ventral no chão com os tornozelos afastados na largura do quadril (com os maléolos laterais das fíbulas na mesma linha que os trocânteres maiores dos fêmures), os dedos de cada pé direcionados para baixo em direção ao chão, os ombros e os cotovelos estavam em flexão de 90 graus e os antebraços e as mãos direcionados para frente e posicionados no chão, aproximadamente na largura dos ombros (com os epicôndilos laterais dos úmeros na mesma linha da região lateral dos acrômios das escápulas) 17,32,69 .…”

“…Em relação ao core, um recente estudo de George et al 32 predisse a resistência máxima do core por meio da avaliação da performance do tempo até alcançar a PSE de oito para a escala de Borg 10, sugerindo que essa aproximação da PSE em oito, poderia ser usada para avaliar a intensidade inicial e prescrever exercício para treinamento do core 32 . Em outro estudo, Cruz-Montecinos et al 17 indicaram que a PSE apresenta alta correlação para o músculo RA no exercício prancha ventral até a falha.…”