Abstract

The purpose of this study was to evaluate the use of nonexercise (N-EX) data, specifically, the Perceived Functional Ability (PFA) and Physical Activity Rating (PA-R) questionnaires, with the treadmill walk-jog-run protocol to estimate VO2max in 12 to 17 year old boys and girls. Ninety-one participants (49 males and 42 females) took part in this study. Data were collected via PFA and PA-R questionnaires, a walk-jog-run submaximal treadmill test, and a maximal graded exercise test (GXT). Data collected included gender, age, height, weight, PFA and PA-R scores, heart rate (HR), treadmill speed, maximal treadmill grade, respiratory exchange ratio (RER), rating of perceived exertion (RPE), and VO2max. Regression analysis resulted in the development of two valid and reliable models to predict VO2max. Nonexercise and submaximal exercise test data were used to build the following model: VO2max (mL∙kg-¹∙min-¹) = 11.201 + (6.877 x Gender; 0 = female; 1 = male) + (3.573 x treadmill speed; mph) – (0.174 x kg) + (0.405 x PFA score) + (0.653 x PA-R score) + (1.019 x age). The model resulted in an R2 = 0.69 and a SEE = 5.16 mL∙kg-¹∙min-¹. Maximal exercise test data were used to build the following model: VO2max (mL∙kg-¹∙min-¹) = -3.264 + (3.359 x Gender; 0 = female; 1 = male) – (0.082 x kg) + (7.351 x treadmill speed; mph) + (1.750 x maximal treadmill grade). The model resulted in an R2 = 0.88 and a SEE = 3.16 mL∙ kg-¹∙min-¹. The cross-validation PRESS statistics for both models demonstrated minimal shrinkage in the accuracy of the regression model. The results of this study demonstrate, for the first time, that N-EX data can be used to accurately predict VO2max in youth. The submaximal and maximal exercise tests validated in this study can be used to assess cardiorespiratory fitness of youth having a wide range on interests and fitness levels. In addition, the use of PFA and PA-R questionnaires enforces initiatives to increase physical activity among youth. Both exercise tests use a self-selected treadmill speed that elicits a steady-state HR of 70% of the participants age-predicted maximal HR. The use of a self-selected walking, jogging, or running speed accommodates youth with different levels of physical fitness, motivation, and interests. The exercise test protocol presented in this study is practical for use in schools, athletic facilities, and community fitness centers. The equipment required to administer the exercise test presented in this study is limited to a treadmill and a HR monitor. Together with the use of PFA and PA-R questionnaires, the submaximal and maximal exercise tests are efficacious to coaches, fitness professionals, and physical educators in a variety of settings.

Degree

College and Department

Life Sciences; Exercise Sciences

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