A comparison of lactate concentration in plasma collected from the toe, ear, and fingertip after a simulated rowing exercise

Objective- The purpose of this study was to examine the validity of using blood taken from the toe for the assessment of plasma lactate concentration in rowers. To achieve this, values were compared with those taken from the fingertip and earlobe.
Methods- Subjects (n=9) exercised at two separate submaximum workloads on the Concept II rowing ergometer. The loads, each lasting four minutes, elicited mean (SD) heart rate responses of 160.1 (8.5) beats per minute and 180.1 (5.7) beats per minute, which corresponded to 76.4 (6.1)% and 91.9 (4.7)% of the individual’s estimated heart rate maximum. Blood was simultaneously removed following the cessation of exercise by three experimenters and was analysed for plasma lactate concentration.
Results- At 76.4% of the individual’s estimated heart rate maximum, the mean (SD) plasma lactate concentrations sampled from the fingertip, toe and earlobe were 6.36 (1.58), 5.81 (1.11) and 5.29 (1.24) mmol/l respectively. At 91.9% of the individual’s estimated heart rate maximum, respective values were 8.81 (2.30), 8.53 (1.37) and 8.41 (2.35) mmol/l. No significant differences (P>0.05) were found between any of the sites at either work intensity.
Conclusions- It was concluded that the toe may offer a practical alternative for assessing the concentration of lactate during rowing, having the advantage that repeated blood samples can be removed without interrupting the rowing action.

Key terms: blood sampling site; lactate; ergometer rowing