A new ventilatory threshold equation for aerobically trained men and women.

The purposes of the present study were to (i) modify previously published ventilatory threshold (VT) equations using the constant error (CE) values for aerobically trained individuals from a recent study; (ii) cross-validate the modified equations to determine their accuracy for estimating VT in aerobically trained individuals; (iii) derive a new non-exercise based equation for estimating VT in aerobically trained individuals if the modified equations are found to be inaccurate; and (iv) cross-validate the new VT equation using the Predicted REsidual Sum of Squares (PRESS) statistic and an independent sample of aerobically trained individuals. Two hundred and eight (n = 208) aerobically trained men and women (mean +/- SD: age = 38.8 +/- 10.4 year) performed a maximal incremental test on a cycle ergometer to determine the observed VT. The predicted VT values from seven published equations were compared with the observed VT by examining the CE, standard error of estimate, validity coefficient (r), and total error (TE). Cross-validation of the modified equations resulted in high %TE values. Therefore, a new VT equation was derived. Cross-validation of this equation on an independent sample of 72 subjects resulted in a low %TE value. The new model is recommended over previous models for estimating VT in aerobically trained individuals.