[Effect of the time of sample collection after exertion and the specimen handling on the lactate content in the blood of horses].

This research investigates the impact of exercise’s timing and intensity, as well as different methods of sample handling, on the lactate concentration in the blood of horses. The study found that the lactate level typically peaks immediately after intensive exercise, varies depending on the workout’s speed and duration, and can remain stable for up to 60 days in samples treated appropriately.

Lactate Concentration in Relation to Exercise Intensity and Duration

• The researchers categorized the athletic performance of the horses into three groups based on the duration and speed of the workout.
• They found that the average maximum lactate concentration (Lamax) in the horses’ blood varied between these groups: horses undergoing gallop workouts of less than 11 m/s for more than 180 seconds had an average Lamax of 4.5 mmol/l, those running at speeds of more than 11 m/s for less than 180 seconds had a higher average Lamax of 16.3 mmol/l, and horses exercising at speeds less than 11 m/s for less than 180 seconds had an average Lamax of 4.6 mmol/l.
• The highest lactate concentration was observed in horses that exercised intensely (more than 11/m/s) for a short period (less than 180 seconds).
• This indicates that the speed and duration of the exercise significantly impact the lactate concentration in a horse’s blood. Intense, short-duration exercise results in more lactate accumulation compared to less intense, longer-duration exercise.

Lactate Levels Over Time Post-Exercise

• For category A and C exercises (less intense, longer or shorter duration), the peak lactate level (Lamax) was recorded immediately after the workout. For the category B exercise (more intense, shorter duration), the Lamax was noted between the first and tenth minute after the workout.
• This conclusion is critical as it demonstrates that the lactate concentration does not necessarily immediately peak following intense exercise, requiring careful timing of sample collection to accurately measure the peak lactate levels.

Stability of Lactate Concentration in Stored Samples

• The researchers investigated the stability of lactate concentrations in stored samples. They found it does not vary in whole blood samples that were immediately deproteinized after collection and in plasma samples within seven days. When stored in a frozen state, lactate levels remained stable for 60 days.
• However, in whole blood samples treated with Na-heparin or Na-heparin/Na-fluoride and stored at 20-22 degrees C and 4 degrees C, the lactate concentration significantly increased within the first 24 hours.
• This suggests that the method of sample preparation and storage conditions significantly affects measured lactate concentrations.