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

AIM: 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.

METHODS: 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.

RESULTS: 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.

CONCLUSION: 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.