The purpose of the present study was to increase the accuracy of prediction of VO2max from the Canadian Aerobic Fitness Test (CAFT) by modifying the protocol and developing a new equation. Males and females between the ages of 15 and 69 years (n = 129) were tested on four occasions. Each subject performed four submaximal step tests (modified CAFT protocol) and a maximal treadmill test. The modification of the protocol consisted of allowing each subject to complete the number of stages needed to reach a target heart rate of 85% of age-predicted maximum. This required adding a new Stage 8 for men and Stages 7 and 8 for women. The prediction equation resulting from regression analysis was, VO2max (ml.kg-1 x min-1) = 32.0 + 16.0 VO2 - 0.24 Age - 0.17 Wt (R2 - 0.77; delta 2 - 26.6), where VO2 = oxygen cost of stepping at the final level (L.min-1), Age = age (yrs), and Wt = body mass (kg).
A pilot study was conducted to investigate the applicability of the Canadian Aerobic Fitness Test (CAFT) for use in epidemiological studies. Thirty subjects ranging in age from 18 to 65 were evaluated for cardiorespiratory fitness on four separate visits. Protocols used included maximal treadmill testing, maximal step testing, and the CAFT. Results from these evaluations suggested that (a) habituation to the CAFT was negligible; (b) prediction of VO2max from the CAFT in fit subjects remains a problem and further equation development for this group may be necessary; (c) maximal step-test protocols do not result in unequivocal VO2max determinations and may lead to misclassification of fitness level; and (d) although the CAFT correlates highly to treadmill VO2max (r = 0.90), a relatively large standard error may result in as high as a 13% error in estimating VO2max and may lead to problems in classifying fitness in some populations (e.g., older unfit).
Comment In: Can J Sport Sci. 1992 Mar;17(1):73-41322777
The purposes of this study are to assess the reliability of the physical activity components of the Canada Fitness Survey (CFS) questionnaire (N = 64 males, N = 63 females) and the Canadian Aerobic Fitness Test (N = 44 males, N = 52 females) in a sample of subjects between 15 and 80 yr.
The intraclass correlation (rI) for the fitness scores was 0.98. The activity variables showed low to moderate correlations (rI = 0.48-0.53). Correlations were higher for males (rI = 0.38-0.65) than females (rI = 0.28-0.60) for most of the activity variables reported. Males generally report leisure activity more reliably than nonleisure activity, whereas the opposite was true for females. Males reported strenuous activity with higher reliability (rI = 0.86) than females (rI = 0.31). There was considerable variation in the reliability of specific activities. Of the components of physical activity (time, intensity, duration) that comprise the energy expenditure (EE) variable, the least reliably reported is intensity for both males (rI = 0.43) and females (rI = 0.55).
The CFS questionnaire is moderately reliable for most measures of physical activity. Estimates of reliability vary considerably among the various activities and components of these activities and between males and females.
Our purpose was to assess the validity of VO2 max values predicted from The Canadian Aerobic Fitness Test (CAFT) by comparing them with peak VO2 values measured during a maximal treadmill protocol. Male and female subjects, 15-69 yr (n = 129), performed two submaximal exercise tests (CAFT protocol), and one maximal treadmill test. There was no significant heart rate habituation between the first two CAFT protocols. Peak VO2 values measured during the treadmill test (TM) were significantly higher than those predicted from the CAFT whether the sample was analyzed overall or categorized by sex. When the sample was categorized by age group, all but groups 1 (15-19) and 6 (60-69) had treadmill peak VO2 values significantly higher than those predicted using Jetté's equation. Using treadmill measured peak VO2 scores as the gold standard, VO2 max predictions using the CAFT protocol and Jetté equation placed individuals of lower fitness levels more accurately than highly fit individuals, into one of five fitness categories.
This study evaluated the predictive ability of the modified Canadian Aerobic Fitness Test (mCAFT) on an independent sample of subjects and compared it to the original Canadian Aerobic Fitness Test (CAFT). Male and female subjects (n = 154), 15-69 yrs of age, performed the mCAFT and a maximal treadmill test. VO2max scores predicted from the mCAFT equation did not differ significantly from those measured during the treadmill test, whether the sample was analysed overall or categorized by sex, whereas the CAFT (Jetté) equation resulted in VO2max scores that were significantly lower than either the measured values or those predicted using the mCAFT. The strength of the linear relationship between predicted and measured VO2max scores is the same for both the mCAFT (r = 0.88) and CAFT (r = 0.89). However, the mCAFT results in a lower mean square error (37.0 for mCAFT vs. 63.3 for CAFT) and thus is an improvement over the CAFT prediction.