Adaptation of the "Conconi test" to children and adolescents.

A field test for the determination of anaerobic threshold (AT) based on the relationship between work intensity and heart rate was previously developed in adult runners (4) and then applied in various sports activities (3, 5, 9). In the current study the same relationship between running speed (S) and heart rate (HR) was determined in 274 healthy children and adolescents (169 males and 105 females). All tests were performed either outdoors on a 400-m track (n = 159, 110 males and 49 females) or indoors in a gymnasium (n = 115, 59 males and 56 females). The subjects increased their work intensity progressively from low to submaximal speeds. HR was determined by a heart rate monitor (Sport Tester TM PE 3000, Polar Electro, Kempele, Finland). In every subject examined, the linearity of the S-HR relationship was lost at a speed, called deflection speed (Sd), above which the increase in S exceeded the increase in HR. HR at Sd was defined as HRd. The respective test-retest correlation coefficients for Sd, HRd, and slope of the linear part of the graph were 0.990, 0.824, and 0.953 when determined outdoors and 0.996, 0.840, and 0.932 when determined indoors. The outdoor-indoor correlation coefficients were 0.934, 0.855, and 0.282, respectively, for Sd, HRd, and slope. The results suggest that application of this test to children and adolescents in running may prove useful in cross-sectional and longitudinal studies of the development of aerobic power during growth.