Toe and earlobe capillary blood sampling for lactate threshold determination in rowing.

Area of Science:

• Sports Medicine
• Exercise Physiology
• Biochemistry

Background:

• Lactate threshold (Tlac) is a key indicator of aerobic fitness in athletes.
• Non-invasive blood sampling methods are desirable during intense exercise like rowing.
• Previous research has not extensively compared toe tip and earlobe blood sampling for Tlac determination.

Purpose of the Study:

• To investigate if blood sampling site (toe tip vs. earlobe) influences lactate threshold determination during rowing ergometry.
• To assess the reliability of toe tip blood sampling for continuous monitoring during exercise.

Main Methods:

• Ten physically active males underwent a rowing ergometer protocol.
• Simultaneous blood samples were collected from the toe tip and earlobe between exercise stages.
• Three distinct methods were employed to determine the lactate threshold (Tlac).

Main Results:

• The method used for Tlac determination had a greater impact on results than the blood sampling site.
• Significant variations in Tlac were observed based on the determination method (P = .004).
• Sampling site differences were not statistically significant (P = .45), but greatest discrepancies in Tlac occurred with the TlacΔ1 method.

Conclusions:

• The toe tip is a viable site for blood collection during rowing ergometry.
• Caution is advised when interchanging earlobe and toe tip samples for training intensity prescription based on Tlac.
• Particular care is needed when using the TlacΔ1 method or at lower lactate concentrations.