30 Years of Lactate Thresholds - what remains to be done?

In 1976. the aerobic-anaerobic threshold first defined a point on the lactate power Curve as a) a transition from aerobic to partly anaerobic energy metabolism, b) an indicator of aerobic performance and c) a means of predicting exercise intensities in endurance training. Subsequent threshold concepts detected selected changes of the lactate power curve either based upon theories concerning lactate formation and utilisation or on empirical training observations. Studies on the highest steady state of lactate during prolonged constant workload, termed maxLass or MLSS, support the idea of a transition from aerobic to partly anaerobic energy metabolism. The shape of the lactate power curve and corresponding thresholds are testing-protocol dependent. Thresholds as well as performances at other arbitrarily-selected points on the lactate power curve correlate comparably well with MLSS power and maximum endurance performance. There is no consistent theory or experimental evidence for an interrelationship between MLSS, MLSS exercise intensity and aerobic performance, nor that thresholds indicate superior training intensities. Mechanisms linking lactate concentrations with specific training effects remain unclear. There is no need for new lactate threshold concepts. Existing data should be used to identify reference values in order to adjust lactate performance testing to biomedical standards. Prospective and observatory training Studies should advance knowledge regarding the meaning of specific lactate concentrations for achieving defined training effects. Computer modelling appears to be underused in developing and testing hypotheses on complex effects related to new findings at (sub-)cellular level and their meaning for exercise testing, lactate power curve and training.