A comparison of the PWC170 and 20-MST tests of aerobic fitness in adolescent schoolchildren.

The aim of this study was to compare the validity of two field tests of aerobic fitness for predicting maximal oxygen uptake (VO2max) in a group of adolescent schoolchildren. Twenty four schoolboys (means age = 15.6 +/- 0.6 yr) and twenty four schoolgirls (means age = 15.4 +/- 0.7 yr) underwent three different tests of aerobic capacity, with one week separating each assessment. The test were: (a) VO2max, using a continuous, progressive treadmill protocol, (b) a physical work capacity test at a heart rate of 170 beats per minute (PWC170), and (c) a 20-metre endurance shuttle run (20-MST), using a modified lapscoring protocol. Heart rates were monitored continuously in all tests. Results (means +/- SD) for boys n = 23) and girls (n = 18) respectively were: VO2max, 53.3 +/- 5.9 and 42.6 +/- 5.8 ml.kg-1.min-1; PWC170, 2.84 +/- 0.47 and 1.86 +/- 0.39 w.kg-1; 20-MST, 81.7 +/- 15.9 and 50.4 +/- 12.5 laps. Linear regression of PWC170 and 20-MST on VO2max scores (n = 41), revealed similarly high powers of prediction for both field tests (PWC170 vs VO2max, r = 0.84; 20-MST vs VO2max, r = 0.87), with an indication that the shuttle run test may be preferable for use with girls. In conclusion, the PWC170 and 20-MST field tests both appear to be valid predictors of VO2max in adolescent schoolchildren. However constraints of time and tester expertise favour the 20-MST for the assessment of aerobic capacity in the field.