A noninvasive method of determining the anaerobic threshold in children.

In 72 11-year-old male and female children the anaerobic threshold (AT) was determined on a treadmill with the invasive method of the lactate test. After a break of 45 min an alternative method for determining AT on a bicycle ergometer was used. A loading method with an increment of 10 W/min was chosen. At AT a characteristic deflection from linearity in the heart rate could be recorded. The comparison between the heart rate at the point of deflection and the heart rate at AT determined invasively shows an outstandingly high correlation (r = 0.98; P less than 0.0001). Consequently, the authors came to the conclusion that it is possible to use the deflection from linearity of the heart rate in tests on bicycle ergometer for training optimization in 11-year-old children if the proper degree of load increase is chosen. This simple method can substitute a more laborious invasive way of determining AT.