The way psychometric and neurophysiological measurements of fatigue are connected is not well understood. Thus, the time course of perceived effort changes due to fatigue, as well as the peripheral and central neurophysiological changes accompanying fatigue, were evaluated. Twelve healthy participants (35 ± 9 years old) undertook 10 min intermittent isometric fatiguing exercise of elbow flexors at 50% of maximum voluntary contraction (MVC). Perceived effort ratings, using the 0–10 numeric rating scale (NRS), were recorded at midrange of MVC. Single pulse TMS of the left motor cortex and electrical stimulation over the biceps muscle was used for the assessment of voluntary activation and peripheral fatigue. The fatiguing exercise caused a 44% reduction in the MVC (p < .001) accompanied by an 18% nonsignificant reduction of the biceps MEP amplitude. The resting twitch force decreased (p < .001) while the superimposed twitches increased (p < .001) causing a decrease (19%) of the voluntary activation (p < .001). The perceived effort ratings increased by 1 point at 30%, by 2 points at 50% MVC respectively on the NRS (p < .001) and were accompanied by an increase in mean biceps EMG. A substantial role of the perceived effort in the voluntary motor control system was revealed.
Sofia I. Lampropoulou and Alexander V. Nowicky
Kevin L. Lamb
This study assessed and compared the validity of children’s effort ratings using the established Borg 6–20 Rating of Perceived Exertion (RPE) scale and a recently devised Children’s Effort Rating Table (CERT) during continuous cycle ergometry. Seventy school children were randomly assigned to one of two groups: Group 1 (RPE) and Group 2 (CERT). Both groups received two incremental exercise trials (Trial 1 and Trial 2) 7 days apart. For both scales, data analysis yielded significant (p < .01) Pearson correlations between perceived effort ratings and heart rate (HR) (rs ≥ .50) and perceived effort and absolute power outputs (rs ≥ .59). Moreover, correlations for CERT were consistently higher than for RPE. Test-retest intraclass correlations of R = .91 (CERT) and R = .90 (RPE) revealed that both scales were reliable. These data suggest that among preadolescent children the traditional scale (RPE) is not the only, nor indeed the best, option for monitoring perceived exertion during controlled exercise.
Tristan L. Wallhead and Nikos Ntoumanis
This study looked at the influence of a Sport Education intervention program on students’ motivational responses in a high school physical education setting. Two intact groups were assigned curricular interventions: the Sport Education group (n = 25), which received eight 60-min lessons, and the comparison group (n = 26), which received a traditional teaching approach to sport-based activity. Pre- and postintervention measures of student enjoyment, perceived effort, perceived competence, goal orientations, perceived motivational climate, and perceived autonomy were obtained for both groups. Repeated-measures ANOVAs showed significant increases in student enjoyment and perceived effort in the Sport Education group only. Hierarchical regression analyses revealed that increases in task-involving climate and perceived autonomy explained a significant amount of unique variance in the Sport Education students’ postintervention enjoyment, perceived effort, and perceived competence responses. The results suggest that the Sport Education curriculum may increase perceptions of a task-involving climate and perceived autonomy, and in so doing, enhance the motivation of high school students toward physical education.
Diane K. Ehlers and Jennifer L. Huberty
The purpose of this study was to describe which theory-based behavioral and technological features middle-aged women prefer to be included in a mobile application designed to help them adopt and maintain regular physical activity (PA).
Women aged 30 to 64 years (N = 120) completed an online survey measuring their demographics and mobile PA application preferences. The survey was developed upon behavioral principles of Social Cognitive Theory, recent mobile app research, and technology adoption principles of the Unified Theory of Acceptance and Use of Technology. Frequencies were calculated and content analyses conducted to identify which features women most preferred.
Behavioral features that help women self-regulate their PA (PA tracking, goal-setting, progress monitoring) were most preferred. Technological features that enhance perceived effort expectancy and playfulness were most preferred. Many women reported the desire to interact and compete with others through the application.
Theory-based PA self-regulation features and theory-based design features that improve perceived effort expectancy and playfulness may be most beneficial in a mobile PA application for middleaged women. Opportunities to interact with other people and the employment of social, game-like activities may also be attractive. Interdisciplinary engagement of experts in PA behavior change, technology adoption, and software development is needed.
Herbert W. Marsh
Physical activity measures for a large, nationally representative sample of Australian boys and girls aged 9, 12, and 15 were related to multiple dimensions of physical fitness. Physical activity during a one-week period was only modestly related to physical fitness. However, relations tended to be higher for length of time multiplied by METs (METs - minday1) than for time alone, time multiplied by perceived effort, or METs - min day−1 multiplied by effort, whereas time multiplied by effort did no better than time alone. Relations tended to be nonlinear in that progressively higher levels of activity had less positive associations with physical fitness. The pattern and size of the relations were consistent across scores for boys and girls aged 9 to 15. Self-report measures of typical and recent (within one week) physical activity both contributed to the prediction of physical fitness, indicating that both aspects of physical activity are important.
Kevin L. Lamb
This study examined the validity and reliability of the Rating of Perceived Exertion (RPE) scale and the Children’s Effort Rating Table (CERT) as methods of regulating exercise intensity during discontinuous cycle ergometry. Sixty-four school children (ages 9–10) were randomly assigned to one of two groups, RPE or CERT, and received two trials 7 days apart. On both occasions, subjects produced 4 × 4-min scale-specific exercise intensities—3, 5, 7, and 9 (CERT) or 8, 12, 15, and 18 (RPE)—interspersed with 2-min rest periods. Analyses yielded significant (p < .01) correlations between perceived effort levels and objective measures: r = .47 to .61 (heart rate) and r = .59 to .75 (power output). Intraclass correlations indicated satisfactory overall repeatability of the produced exercise intensities (R > .70), but some notable inconsistencies were observed. The usefulness of effort perception scales among preadolescent children is presently rather limited, probably due to a number of confounding factors that need to be systematically addressed.
Michael J. Axe, Thomas C. Windley and Lynn Snyder-Mackler
To design interval throwing programs for baseball players other than pitchers from 13 years of age to the college level.
The authors recorded throws to base, distance of throws, and perceived effort of throws at 4 levels of play. For catchers they also recorded number of throws to the pitcher, number of sprints to first or third base, and time in the squat stance. From these data they designed throwing programs specific to outfielders, infielders, and catchers.
No significant difference was found between the number of throws and distance of throws for infielders and catchers across all age groups. The mean distance of throws differed significantly between 13-year-olds and all other levels of play.
The authors devised 1 program for infielders and catchers of all age groups, 1 program for 13-year-old outfielders, and 1 for all other levels.
Tristan Wallhead, Alex C. Garn, Carla Vidoni and Charli Youngberg
Sport Education has embedded pedagogical strategies proposed to reduce the prevalence of amotivation in physical education. The purpose of this study was to provide an examination of the game play participation rates of amotivated students within a Sport Education season. A sample of 395 high school students participated in a season of team handball. A multistep cluster analysis approach revealed three motivational profiles: amotivated, moderate and high clusters. A priori analyses revealed differences in perceived effort, enjoyment, and need satisfaction across the three profile groups. Game play participation rates coded throughout the season revealed no significant differences in ball engagement or success rates across motivational profile groups. A significant difference occurred in active game participation between the high and amotivated students. Results suggest that Sport Education elicits a level of inclusive game play participation across students of different motivational profiles.
Thomas J. Birk and Marianne Mossing
The purpose of this study was to determine whether heart rate and ventilation can be predicted from RPE. Also, this study determined whether breathing or heart rate sensations caused perceived effort or strain (degree of perceived central strain). Eight ambulatory active teenagers (ages 13-16 years, M= 14.75) with spastic cerebral palsy performed a discontinuous maximum bicycle ergometer protocol. Rate of perceived exertion (RPE), heart rate (HR) (V5 lead), and V̇E (Wright respirometer) were recorded each minute. Results indicated that Minutes 1 and 2 of Stage 1 were significantly correlated for RPE and ventilation, and RPE and heart rate were significantly correlated for Minutes 3 and 4 of Stages 1 and 2. Low standard error of estimates values were also evident for each of these minutes wherein significant correlations resulted. Initially, pulmonary strain was perceived as greater than HR for a given RPE value. However, by the conclusion of the second stage, breathing was slightly less than cardiac strain. Results suggest that RPE can be used to predict heart rate after the 2nd minute of discontinuous exercise training or testing. The accurate estimation of ventilation for the initial minutes of exercise may be limited since some anxiety, secondary to hyperventilation, could result. Also, breathing is perceived as a greater strain than heart rate initially but appears to equal and be slightly lower at the conclusion of aerobic exercise.
Boris I. Prilutsky
In this response, the major criticisms of the target article are addressed. Terminology from the target article that may have caused some confusion is clarified. In particular, the tasks that have the basic features of muscle coordination, as identified in the target article, have been limited in scope. Anew metabolic optimization criterion suggested by Alexander (2000) is examined for its ability to predict muscle coordination in walking. Issues concerning the validation of muscle force predictions, the rules of muscle coordination, and the role of directional constraints in coordination of two-joint muscles are discussed. It is shown in particular that even in one-joint systems, the forces predicted by the criterion of Crowninshield and Brand (1981) depend upon the muscle moment arms and the physiological cross-sectional areas in much more complex ways than either previously assumed in the target article, or incorrectly derived by Herzog and Ait-Haddou (2000). It is concluded that the criterion of Crowninshield and Brand qualitatively predicts the basic coordination features of the major one- and two-joint muscles in a number of highly skilled, repetitive motor tasks performed by humans under predictable conditions and little demands on stability and accuracy. A possible functional significance of such muscle coordination may be the minimization of perceived effort, muscle fatigue, and/or energy expenditure.