Lactate minimum test during incremental running after a submaximal cycling exercise: a novel test with training...

The purpose of the present study was to determine whether running speed determined in a lactate minimum test (lactate minimum intensity, LMI) during a treadmill incremental exercise performed just after submaximal cycling corresponds to the speed of a respiratory exchange ratio of 1.00 (RER-1) and, by extension, to the maximal lactate steady state (MLSS) previously obtained in a standard incremental exercise test.

Eighteen moderately trained triathletes (15 men, 3 women) underwent two exercise sessions 72 h apart in random order: 1) a standard incremental treadmill test to identify the speed corresponding to RER-1, and 2) a submaximal exercise test on a bicycle-ergometer to obtain the LT (lactate threshold) followed by the incremental portion of the lactate minimum test on the treadmill.

No significant differences were detected between running speed and heart rate at RER-1 and LMI (14.44±1.24 vs. 14.11±1.36 km·h-1 and 166.38±9.30 vs. 169.55±8.97 beats·min-1, respectively). Moreover, 95% of the differences between the results of the two incremental tests for running speed and heart rate were within the limits of agreement.

These findings suggest the possibility of obtaining a valid physiological profile of a triathlete using a single test to assess the level of training in both cycling and running.