Int J Sports Med 1998; 19(5): 349-357
DOI: 10.1055/s-2007-971929
Training and Testing

© Georg Thieme Verlag Stuttgart · New York

The Reliability of Lactate Measurements During Exercise

P. Pfitzinger, P. S. Freedson
  • Department of Exercise Science, University of Massachusetts, Anherst, MA, USA
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Publikationsverlauf

Publikationsdatum:
09. März 2007 (online)

The purpose of this study was to establish the reliability of lactate threshold (LT) measurement across days. Twelve endurance-trained males aged 21 - 44 years participated in the study. Blood lactate concentration in capillary whole blood was measured at rest and at completion of 5 minute stages on a treadmill at 60 %, 65 %, 71 %, 77 %, 83 % and 89 % of VO2max during 3 separate days of testing. Velocity at LT (LTVEL), oxygen consumption at LT (LTVO2), and heart rate at LT (LTHR) are determined using each of the following criteria: fixed lactate concentrations of 2.0 mmol, 2.5 mmol, and 4.0 mmol, the breakpoint of the lactate-intensity curve, 1 mmol above rest, and 1 mmol above exercise baseline. A one factor repeated measures AMOVA model was used to calculate intraclass reliability coefficients across the 3 testing sessions. Confidence intervals (95 %) were calculated around the point estimates of reliability for each LT criterion. Intraclass correlation coefficients ranged from 0.98 to 0.99 LTVEL (SEM 0.06 to 0.14 km · hr-1). from 0.91 to 0.96 for LTVO2 (SEM 0.34 to 0.72 ml · kg-1 · min-1), and from 0.75 to 0.96 for LTHR (SEM 0.7 to 1.9 beats · min-1). These results support the reliability of LTVEL, LTVO2, and LTHR measurement.