Reliability and validity of measures taken during the Chester step test to predict aerobic power and to prescribe aerobic exercise

Abstract

Objectives: To evaluate the reliability and validity of measures taken during the Chester step test (CST) used to predict VO 2 max and prescribe subsequent exercise. Methods: The CST was performed twice on separate days by 7 males and 6 females aged 22.4 (SD 4.6) years. Heart rate (HR), ratings of perceived exertion (RPE), and oxygen uptake (VO 2 ) were measured at each stage of the CST. Results: RPE, HR, and actual VO 2 were the same at each stage for both trials but each of these measures was significantly different between CST stages (p,0.0005). Intertrial bias ¡95% limits of agreement (95% LoA) of HR reached acceptable limits at CST stage IV (22¡10 beats/min) and for RPE at stages III (0.2¡1.4) and IV (0.5¡1.9). Age estimated HRmax significantly overestimated actual HRmax of 5 beats/min (p = 0.016) and the 95% LoA showed that this error could range from an underestimation of 17 beats/min to an overestimation of 7 beats/min. Estimated versus actual VO 2 at each CST stage during both trials showed errors ranging between 11% and 19%. Trial 1 underestimated actual VO 2 max by 2.8 ml/kg/min (p = 0.006) and trial 2 by 1.6 ml/kg/min (not significant). The intertrial agreement in predicted VO 2 max was relatively narrow with a bias ¡95% LoA of 20.8¡3.7 ml/kg/min. The RPE and %HRmax (actual) correlation improved with a second trial. At all CST stages in trial 2 RPE:%HRmax coefficients were significant with the highest correlations at CST stages III (r = 0.78) and IV (r = 0.84). Conclusion: CST VO 2 max prediction validity is questioned but the CST is reliable on a test-retest basis. VO 2 max prediction error is due more to VO 2 estimation error at each CST stage compared with error in age estimated HRmax. The HR/RPE relation at .50% VO 2 max reliably represents the recommended intensity for developing cardiorespiratory fitness, but only when a practice trial of the CST is first performed.T he Chester step test (CST) was originally developed by Kevin Sykes at University College Chester to assess aerobic fitness by predicting maximal aerobic power (VO 2 max) in fire brigades in Britain, Europe, USA, and Asia, and more recently for work with airport firefighters, the ambulance service, health authorities, and corporate institutions.1 It also features in commercial health and fitness assessment packages and most noticeably one in particular (Fitech Pty Ltd, Australia; www.fitech.com.au). The CST is one of many tests designed to provide a safe and practical means of assessing aerobic fitness under submaximal conditions. Examples of other similar tests include the Astrand-Ryhming nomogram cycle ergometer protocol, 2 the American College of Sports Medicine protocols for cycle ergometry and treadmill, 3 and the Canadian standardised step test of fitness. 4 The limited equipment needed (step, heart rate monitor, portable cassette or compact disk player, and perceived exertion scale) makes the CST very portable and requirements for space are minimal, which is advantageous compared with similar protocols using treadmills, shutt...

Validación inicial de la escala de medición de esfuerzo percibido infantil (EPInfant) en niños chilenos

“…Esto sugiere que la prueba de ejercicio se comportó como una prueba de intensidad gradualmente creciente 'submáxima', como ya se ha descrito en la literatura científica. En una muestra de adultos jóvenes sanos (con edad promedio de 22,4 años), Buckley, et al, observaron que la frecuencia cardiaca al final de la prueba de ejercicio alcanzó el 81,1 % de la frecuencia cardiaca máxima; además, la percepción del esfuerzo llegó a 14,2 puntos en la escala de Borg (6 a 20), lo cual equivale a un 71 % del valor máximo teórico (19). En este estudio ningún grupo superó los 8 puntos de esfuerzo percibido.…”

“…Se llevó a cabo la prueba de escalón de Chester, que es una prueba de intensidad creciente y continua validada en sujetos sanos y que se aplica en distintos contextos (19)(20)(21)(22). La prueba consiste en subir y bajar un escalón de 20 cm de altura a una velocidad creciente indicada por una señal sonora.…”

Reproducibility of step tests in patients with bronchiectasis

“…Step Test (CST), which was designed to estimate aerobic capacity in healthy participants [11][12][13] , has also been used among patients with pulmonary disease [14][15][16] . However, the CST is a strenuous protocol because fewer than half of patients in recovery from severe acute respiratory syndrome are able to complete the test 14 .…”

Validity and reliability of the Chester step test for prediction of the aerobic capacity among Iranian students

“…CST is also claimed to be inexpensive, safe, portable and highly applicable and adaptable to a wide range of age and fitness (7). This test was already applied for determination of aerobic fitness of fire brigades in British, European, north American and Asian workers (7,12), disaster personnel (13) and children (14). However, its applicability has not yet been explored among Iranian population.…”

“…Kevin Sykes developed CST at Chester university of United Kingdom. This test was designed to provide a safe and practical procedure for assessing aerobic fitness under submaximal conditions (7,12). CST is also claimed to be inexpensive, safe, portable and highly applicable and adaptable to a wide range of age and fitness (7).…”