ANAEROBIC THRESHOLD IN CHILDREN - DETERMINATION FROM SALIVA ANALYSIS IN-FIELD TESTS

The purpose of this study was to determine the anaerobic threshold of children by the analysis of saliva collected during field tests. A gro up of 25 children (mean age, 10.5 years) performed an incremental exer cise test on a track, consisting of 4-min stages at increasing running velocities. Before each test (at rest) and at the end of each stage, both blood (via finger pricks) and saliva samples (for measurement of salivary concentrations of Na+ and Cl-) were collected to determine la ctate threshold (Th-la-) and saliva threshold (Th-sa), respectively. T here were no significant differences between values of Th-la- and Th-s a when expressed either as running velocity [mean Th-la-, 10.73 (SD 1. 96) km . h(-1); mean Th-sa, 10.89 (SD 1.69) km . h(-1)] or heart rate [Th-la-, 182(SD 14) beats . min(-1) Th-sa 183 (SD 11) beats . min(-1)] . In addition, correlations between Th-sa and Th-la were high, when bo th values were expressed as running velocity in kilometres per hour (r = 0.89; P < 0.001), or heart rate in beats per minute (r = 0.90; P < 0.001). In conclusion, these findings suggested that saliva analysis w ould be a valid method for anaerobic threshold determination in field tests.