Aim: The purpose of this study was to compare the blood-lactate and heart rate response of three treadmill tests and to define a conversion algorithm.
Methods: Subjects included 19 long-distance runners. The first two tests had increments of 2 km/h every 3 (test3m) or 5 minutes (test5m). The third test (testFm) consisted of four consecutive 2000m-runs. The calculated individual-anaerobic-threshold (IAT) from test3m was defined as speed at the third step of testFm, speed-increments between the four steps were 0.25 m/s.
Results: Lactate threshold (LT) did not show significant differences. Speed at IAT in test3m (15.09|*plusmn*|2.29 km/h) was significantly higher than in test5m (14.74|*plusmn*|2.22 km/h), heart rates were nearly identical. Speed and heart rate at 2 mmol/L showed no significant differences. At lactate concentrations of 3 and 4 mmol/L, running-speeds in test3m were significantly higher than in test5m and testFm. Heart rate were the same in test3m and test5m but significantly higher in testFm.
Conclusion: Taking test3m as basis for determining endurance-performance, an adjustment of test5m can be made by adding 1.8 mmol/l instead of 1.5 mmol/l to the LT to derive the IAT. TestFm shows similar results as test5m, however, standardization is difficult due to variable increment durations.