Perceived Exertion: Revisiting the History and Updating the Neurophysiology and the Practical Applications.

The perceived exertion construct creation is a landmark in exercise physiology and sport science. Obtaining perceived exertion is relatively easy, but practitioners often neglect some critical methodological issues in its assessment. Furthermore, the perceived exertion definition, neurophysiological basis, and practical applications have evolved since the perceived exertion construct's inception. Therefore, we revisit the careful work devoted by Gunnar Borg with psychophysical methods to develop the perceived exertion construct, which resulted in the creation of two scales: the rating of perceived exertion (RPE) and the category-ratio 10 (CR10). We discuss a contemporary definition that considers perceived exertion as a conscious perception of how hard, heavy, and strenuous the exercise is, according to the sense of effort to command the limbs and the feeling of heavy breathing (respiratory effort). Thus, other exercise-evoked sensations would not hinder the reported perceived exertion. We then describe the neurophysiological mechanisms involved in the perceived exertion genesis during exercise, including the influence of the peripheral feedback from the skeletal muscles and the cardiorespiratory system (i.e., afferent feedback) and the influence of efferent copies from the motor command and respiratory drive (i.e., corollary discharges), as well as the interaction between them. We highlight essential details practitioners should consider when using the RPE and CR10 scales, such as the perceived exertion definition, the original scales utilization, and the descriptors anchoring process. Finally, we present how practitioners can use perceived exertion to assess cardiorespiratory fitness, individualize exercise intensity prescription, predict endurance exercise performance, and monitor athletes' responses to physical training.

Rating of Perceived Exertion as a Method to Determine Training Loads in Strength Training in Elderly Women: A Randomized Controlled Study.

Objective: The aim of this study was to compare the effects of training using loads from a repetition maximum value (%1RM) and rating of perceived exertion (RPE) in elderly women. Methods: Twenty-five elderly women (60-75 years old) were randomly assigned to a group that trained using loads determined by 1RM test (G%; n = 12) or to a group that trained using loads determined by RPE (GPE; n = 13). Elderly women trained for 12 weeks using five exercises performed with 2-3 sets of 8-15 repetitions. Loads progressed from 45% to 75% of 1RM (G%) and from 13 to 18 from Rating Perceived Exertion of Borg Scale (GPE). The outcome measures, 1RM and maximum repetitions (RMs with 70% 1RM), were assessed before, between and after training programs. Results: Increased 1RM value and RMs were observed in both groups (20-42%, p < 0.001 and 56-76%, p < 0.001, respectively, for %G; and 17-56%, p < 0.001 and 47-106%, p < 0.001, respectively, for GPE), without differences between them. Conclusions: Prescribing loads using the RPE and 1RM might be similarly effective for training elderly women in order to promote strength gains. As a practical application, RPE could be an additional method to determine training loads. In spite of the promising results of the present study, it is not possible to state that the use of RPE is effective in monitoring loads during sub maximal strength training in elderly and more research must be carried out to confirm it.

Predicting Lactate Threshold With Rate of Perceived Exertion in Young Competitive Male Swimmers.

The purpose of this study was to verify the effectiveness of the rate of perceived exertion threshold (RPET) for predicting young competitive swimmers' lactate threshold (LT) during incremental testing. We enrolled 13 male athletes (M age = 16, SD = 0.6 years) in an incremental test protocol consisting of eight repetitions of a 100-meter crawl with 2-minute intervals between each repetition. We collected data for blood lactate concentration ([La]) and Borg scale rate of perceived exertion (RPE) at the end of each repetition. The results obtained were: M RPET = 4.98, SD = 1.12 arbitrary units (A.U.) and M lactate threshold = 4.24, SD = 1.12 mmol.L-1, with [La] and RPE identified by the maximal deviation (Dmax) method without a significant difference (p > 0.05) and large correlations between DmaxLa and DmaxRPE at variables for time (r = 0.64), velocity (r = 0.67) and percentage of personal best time (PB) (r = 0.60). These results suggest that RPET is a good predictor of LT in young competitive swimmers.

Fatores determinantes da estratégia de ritmo em esportes de endurance / Determinants factors of pacing strategy on endurance sports / Determinantes de la estrategia de ritmo en los deportes de resistencia

Resumo Provas cíclicas de longa duração exigem que atletas tomem decisões acerca do uso de energia durante a prova. Visto isso, diferentes estratégias de ritmo (pacing strategy) foram diagnosticadas a fim de promover uma economia de energia durante o esforço. Portanto, o objetivo desta revisão é apresentar os principais mecanismos da estratégia de ritmo, baseados nos modelos de tomada de decisão sustentados por informações aferentes ou contextuais/intuitivas, que são usadas para calcular e reduzir um possível risco de fadiga prematura durante uma tarefa de endurance.

Abstract Long cyclic exercises require that athletes make decisions about the use of energy during the trial, as this, different pacing strategies were diagnosed in order to promote an economy of energy during exercise. Therefore the aim of this review was to present the major exercise strategy mechanisms, based on the decision-making models supported by accurate afferent information, or contextual / intuitive, which are used to calculate the risk of the exercise/test, and decide to reduce/maintain/increase the pace of exercise/test.

Resumen Las pruebas cíclicas a largo plazo requieren que los atletas tomen decisiones sobre el uso de la energía durante la carrera. De esta manera, se diagnosticaron diferentes estrategias de ritmos (pacing strategy) con el fin de promover una economía de energía durante el esfuerzo. Por tanto, el objetivo de esta revisión es presentar los principales mecanismos de la estrategia de ritmo, basados en los modelos de toma de decisiones con el apoyo de la información aferente exacta, o contextual/intuitiva, que se utiliza para calcular el posible riesgo de cansancio prematuro durante la prueba de resistencia.

Effects of caffeine on neuromuscular fatigue and performance during high-intensity cycling exercise in moderate hypoxia.

PURPOSE: To investigate the effects of caffeine on performance, neuromuscular fatigue and perception of effort during high-intensity cycling exercise in moderate hypoxia. METHODS: Seven adult male participants firstly underwent an incremental exercise test on a cycle ergometer in conditions of acute normobaric hypoxia (fraction inspired oxygen = 0.15) to establish peak power output (PPO). In the following two visits, they performed a time to exhaustion test (78 ± 3% PPO) in the same hypoxic conditions after caffeine ingestion (4 mg kg-1) and one after placebo ingestion in a double-blind, randomized, counterbalanced cross-over design. RESULTS: Caffeine significantly improved time to exhaustion by 12%. A significant decrease in subjective fatigue was found after caffeine consumption. Perception of effort and surface electromyographic signal amplitude of the vastus lateralis were lower and heart rate was higher in the caffeine condition when compared to placebo. However, caffeine did not reduce the peripheral and central fatigue induced by high-intensity cycling exercise in moderate hypoxia. CONCLUSION: The caffeine-induced improvement in time to exhaustion during high-intensity cycling exercise in moderate hypoxia seems to be mediated by a reduction in perception of effort, which occurs despite no reduction in neuromuscular fatigue.

Percepção subjetiva do esforço em jogos oficiais de Futsal / Perception subjective effort in official Futsal games

O objetivo do presente estudo foi quantificar a intensidade dos esforços utilizando o método da PSE em partidas oficiais de futsal. A amostra foi constituída por 10 atletas do sexo masculino (16,5±2 anos) que participaram da etapa estadual dos Jogos Escolares da Juventude. Foi avaliado o comportamento da percepção subjetiva de esforço (PSE) em resposta à cinco jogos oficiais de futsal na categoria sub-17, sendo dois pela fase classificatória e três pela fase final da competição. A quantificação da carga interna foi determinada através do método da PSE da sessão (FOSTER et, al., 2001). Foram encontrados valores médios de 7,5 e 7,4 para as partidas da 1ª fase e 8,2, 8,7 e 8,9 para os jogos da fase final. Os resultados indicam cargas crescentes ao longo da competição, demonstrando que os jogos foram realizados com intensidades elevadas, compatíveis com intensidades de partidas de futsal analisadas utilizando outros indicadores, como frequência cardíaca e lactato. Pode-se concluir que a PSE é um método confiável para mensurar a intensidade dos esforços em partidas oficiais de futsal.(AU)

The aim of this study was to quantify the degree of effort using the method of PSE in official games of futsal. The sample consisted of 10 male athletes (16.5 ± 2 years) who participated in the state level of School Youth Games. The behavior of perceived exertion (RPE) in response to the five official games of futsal in the under-17 category was evaluated, two and three through the qualifying for the final stage of the competition. The quantification of the internal load was determined by the session SPE (Foster et, al. 2001) method. Average values of 7.5 and 7.4 for departures from 1st stage and 8.2, 8.7 and 8.9 for the finals matches were found. The results indicate increasing loads throughout the competition, demonstrating that the games were held at high intensities, consistent with intensities of futsal matches analyzed using other indicators such as heart rate and lactate. Can conclude that the PSE is a reliable method to measure the intensity of the efforts in official games of futsal.(AU)

Alteraciones emocionales y la relación con las cargas de entrenamiento en nadadores de alto rendimiento / Emotional alterations and training loads in high performance swimmers / Alterações emocionais e da carga de treinamento em nadadores de alto rendimento

Resumen El objetivo de este estudio fue evaluar la relación entre la carga de entrenamiento y el estado de ánimo durante un macrociclo. Veinte nadadores velocistas de alto rendimiento, de ambos sexos fueron evaluados a través de la Escala de Percepción Subjetiva del Esfuerzo (PSE) y el perfil Brums. La carga de entrenamiento se determina multiplicando kilómetros nadó (volumen) semanalmente por la respuesta del PSE semanal. La correlación de Pearson fue usada para verificar la relación entre la carga de entrenamiento y el estado de ánimo. Los resultados mostraron una correlación positiva entre la carga y la fatiga, y negativa con el vigor (p < 0,01). Por lo tanto, se concluyó que la carga de entrenamiento determinada por la relación entre el volumen y la PSE está relacionada com los estados emocionales, el vigor y la fatiga.

Abstract The aim of this study was to evaluate the relationship between training load and athletes mood states during a macrocycle. Twenty sprinters swimmers of high performance, of both sexes, were evaluated through the Rating of Perceived Exertion (PSE) and the Brums Profile (BR). The training load was determined multiplying the weekly kilometers swam (volume) by the score of the PSE. The Pearson correlation was used to verify the relationship between the training loads and the emotional states. Results showed a positive correlation with fatigue and negative correlation with vigor (p < 0.01). Thus, it was concluded that the training load determined by the relationship between volume and PSE is related to emotional states, vigor and fatigue.

Resumo O objetivo do presente estudo foi avaliar a relação entre a carga de treinamento e o estado de humor durante um macrociclo. Vinte nadadores velocistas de alto rendimento, de ambos os sexos, foram avaliados pela Escala de Percepção Subjetiva de Esforço (PSE) e pelo Perfil Brums. A carga de treinamento foi determinada com a multiplicação dos quilômetros nadados (volume) semanalmente pela resposta da PSE semanal. A correlação de Pearson foi usadaparaverificar a relação entre a carga de treino e o estado de humor. Os resultados mostraram correlação positiva da carga com a fadiga e negativa com o vigor (p < 0,01). Assim, foi possível concluir que a carga de treinamento determinada pela relação entre o volume e a PSE se relaciona com os estados emocionais, o vigor e a fadiga de nadadores.

The psychobiological model: a new explanation to intensity regulation and (in)tolerance in endurance exercise

The mechanisms underpinning fatigue and exhaustion, and the specific sources of exercise-endurance intensity regulation and (in)tolerance have been investigated for over a century. Although several scientific theories are currently available, over the past five years a new framework called Psychobiological model has been proposed. This model gives greater attention to perceptual and motivational factors than its antecedents, and their respective influence on the conscious process of decision-making and behavioral regulation. In this review we present experimental evidences and summarize the key points of the Psychobiological model to explain intensity regulation and (in)tolerance in endurance exercise. Still, we discuss how the Psychobiological model explains training-induced adaptations related to improvements in performance, experimental manipulations, its predictions, and propose future directions for this investigative area. The Psychobiological model may give a new perspective to the results already published in the literature, helping scientists to better guide their research problems, as well as to analyze and interpret new findings more accurately...

Os mecanismos que explicam fadiga e exaustão, controle da intensidade e (in)tolerância ao exercício de resistência cardiorrespiratória têm sido estudados há mais de um século. Apesar de diversas teorias científicas atualmente disponíveis, nos últimos cinco anos um novo modelo chamado de Psicobiológico tem sido proposto. Este modelo dá maior importância aos fatores perceptuais e motivacionais em relação aos seus antecessores, bem como a respectiva influência destes fatores no processo consciente de tomada de decisão e controle comportamental. Nesta revisão, nós apresentamos evidências experimentais e sintetizamos os pontos chaves do modelo Psicobiológico que explicam o controle da intensidade e (in)tolerância ao exercício de resistência cardiorrespiratória. Adicionalmente, nós discutimos como o modelo explica as adaptações ao treinamento relacionadas à melhora no desempenho, as manipulações experimentais e suas predições. Ao final, propomos futuras direções para esta área investigativa. O modelo Psicobiológico pode proporcionar uma nova perspectiva aos resultados anteriormente publicados na literatura, ajudando os cientistas a entenderem melhor seus problemas de pesquisa, assim como analisar e interpretar novas evidências mais precisamente...