Method for quantifying net anaerobic power in exercising horses.

The research article describes a method for measuring net anaerobic power in exercising horses, which can contribute to a more accurate evaluation of the animals’ total metabolic power while they’re exercising at or above their aerobic capacities.

Introduction

• The authors state that there’s a lack of efficient methods for measuring net anaerobic power in exercising horses; such tools can help generate accurate estimates of total metabolic power. They aimed to achieve this by analyzing the increase in maximum oxygen consumption (VO2max) when a horse breathes hyperoxic (HO) gas, expecting a decrease in the rate of plasma lactate accumulation (Mlactate).

Methodology

• Six 3-year-old Thoroughbreds were trained on a treadmill while wearing a semi-open flow mask to measure VO2. After four months of training, the horses were able to run with a reproducible specific VO2max.
• The mask was designed to allow the mixing of oxygen or nitrogen with the inward bias flow of gas, giving researchers control over the oxygen concentration that the horse inhaled. The horses ran at a speed that provoked VO2max in normal oxygen (NO) conditions while their blood was drawn every 15 seconds over 2 minutes to determine Mlactate levels.
• The horses performed this exercise while breathing through three different gas conditions; hyperoxic (higher oxygen concentration), normoxic (normal oxygen concentration), and hypoxic (lower oxygen concentration).

Results

• The researchers found that VO2max per body weight was not significantly different in LO and NO conditions, thus the data from these tests were not used in the comparison.
• In NO and HO conditions, VO2max increased while Mlactate decreased, suggesting that a higher oxygen concentration led to a decrease in lactate production.

Conclusions

• The study found a relationship between changes in Mlactate levels and changes in VO2max per body weight, suggesting a certain amount of Mlactate is associated with net anaerobic power equivalent to a specific measure of aerobic power.
• The authors noted a high variability in VO2max per body weight in data from some runs (especially in lower oxygen concentration), which led them to conclude that caution must be exercised when comparing data from the same horse during different runs.
• Ultimately, the study provides a useful method for estimating net anaerobic power and evaluating total metabolic power of horses exercising at or above their aerobic capacities.