Rating of perceived exertion during two different constant-load exercise intensities during arm cranking in paraplegic and able-bodied participants

Fatigability during volitional walking in incomplete spinal cord injury: cardiorespiratory and motor performance considerations

Fatigability describes the decline in force production (i.e., performance fatigability) and/or changes in sensations regulating performance (i.e., perceived fatigability) during whole-body activity and poses a major challenge to those living with spinal cord injuries (SCI). After SCI, the inability to overcome disruptions to metabolic homeostasis due to cardiorespiratory limitations and physical deconditioning may contribute to increased fatigability severity. The increased susceptibility to fatigability may have implications for motor control strategies and motor learning. Locomotor training approaches designed to reduce fatigability and enhance aerobic capacity in combination with motor learning may be advantageous for promoting functional recovery after SCI. Future research is required to advance the understanding of the relationship between fatigability, cardiorespiratory function and motor performance following SCI.

Objective and subjective methods for quantifying training load in wheelchair basketball small-sided games

The aim of the present study was to analyse the training load in wheelchair basketball small-sided games and determine the relationship between heart rate (HR)-based training load and perceived exertion (RPE)-based training load methods among small-sided games bouts. HR-based measurements of training load included Edwards' training load and Stagno's training impulses (TRIMP_MOD) while RPE-based training load measurements included cardiopulmonary (session RPEres) and muscular (session RPEmus) values. Data were collected from 12 wheelchair basketball players during five consecutive weeks. The total load for the small-sided games sessions was 67.5 ± 6.7 and 55.3 ± 12.5 AU in HR-based training load (Edwards' training load and TRIMP_MOD), while the RPE-based training loads were 99.3 ± 26.9 (session RPEres) and 100.8 ± 31.2 AU (session RPEmus). Bout-to-bout analysis identified greater session RPEmus in the third [P < 0.05; effect size (ES) = 0.66, moderate] and fourth bouts (P < 0.05; ES = 0.64, moderate) than in the first bout, but other measures did not differ. Mean correlations indicated a trivial and small relationship among HR-based and RPE-based training loads. It is suggested that HR-based and RPE-based training loads provide different information, but these two methods could be complementary because one method could help us to understand the limitations of the other.

Wheelchair users' perceived exertion during typical mobility activities

STUDY DESIGN

Each participant performed a series of wheelchair exercises equivalent in intensity to minimal functional speed (1 m s(-1)), functional walking speed (1.3 m s(-1)), a relatively challenging speed (1.6 m s(-1)) and a self-selected speed. Each participant also completed a graded exercise test (GXT) to volitional exhaustion (VO2peak).

OBJECTIVES

The purpose of this study was (1) to assess the physical capacity of wheelchair users as they undertake typical mobility activities and (2) to investigate how closely the components of a differentiated model of perceived exertion mirror wheelchair users' own perception of exertion.

METHODS

Eleven (eight males and three females) spinal cord-injured or congenitally impaired wheelchair-dependent participants volunteered for the study. Differentiated ratings of perceived exertion (RPE_arm and RPE_respiration) and oxygen uptake (VO2) and heart rate were recorded during each exercise.

RESULTS

The mean comfortable speed at which the participants propelled their own wheelchairs on the wheelchair ergometer was 1.1±0.2 m s(-1). Speeds of 1 m s(-1) and 1.3 m s(-1) are typical of everyday functional propulsion. The corresponding RPE_respiration and RPE_arm ranged from 7 to 13 on the Borg scale; the %VO2peak measured in these trials ranged from 37 to 80% VO2peak. For propulsion intensities used in the present study-low, moderate, high and graded exercise intensity-no difference could be observed between RPE_respiration and RPE_arm. There were no significant differences between RPE_arm and RPE_respiration at the termination of the GXT.

CONCLUSION

The current study showed potential for the use of RPE to assess and monitor daily wheelchair propulsion intensity in individuals with paraplegia.

Use of Ratings of Perceived Exertion in Sports

The rating of perceived exertion (RPE) is a recognized marker of intensity and of homeostatic disturbance during exercise. It is typically monitored during exercise tests to complement other measures of intensity. The purpose of this commentary is to highlight the remarkable value of RPE as a psychophysiological integrator in adults. It can be used in such diverse fashions as to predict exercise capacity, assess changes in training status, and explain changes in pace and pacing strategy. In addition to using RPE to self-regulate exercise, a novel application of the intensity:RPE relationship is to clamp RPE at various levels to produce self-paced bouts of exercise, which can be used to assess maximal functional capacity. Research also shows that the rate of increase in RPE during self-paced competitive events of varying distance, or constant-load tasks where the participant exercises until volitional exhaustion, is proportional to the duration that remains. These findings suggest that the brain regulates RPE and performance in an anticipatory manner based on awareness of metabolic reserves at the start of an event and certainty of the anticipated end point. Changes in pace may be explained by a continuous internal negotiation of momentary RPE compared with a preplanned “ideal rate of RPE progression” template, which takes into account the portion of distance covered and the anticipated end point. These observations have led to the development of new techniques to analyze the complex relationship of RPE and pacing. The use of techniques to assess frontal-cortex activity will lead to further advances in understanding.