Longitudinal analysis of lactate threshold in male and female master athletes.

Purpose: The lack of relationship between lactate threshold (LT) and running performance in older runners, and the increase in LT with age, has not been previously studied in a longitudinal design. We evaluated the cross-sectional and longitudinal changes in LT with age and compared the changes in LT with changes in performance variables.

Methods: Fifty-one male and 23 female runners (39-77 yr) performed two graded treadmill exercise tests with minute-by-minute venous blood lactate analysis, separated by 5.8 +/- 1.6 yr (mean +/- SD). Body composition was determined by hydrodensitometry and training history by questionnaire.

Results: There was no change in LBM over time, but significant decreases in [OV0312]O(2max) and training volume irrespective of age and gender (P < 0.05). LT as a percent of [OV0312]O(2max) increased with age (P < 0.05), demonstrated poor stability over time (r = 0.29, P = 0.01) compared with other parameters measured, and changes in LT were not related to changes in fitness or performance.

Conclusion: Based upon these findings, we conclude that the LT may be less precise than [OV0312]O(2max) or performance in the prescription of exercise intensities or as an evaluation tool in older individuals.