Abstract
Reason for performing study: There is no good method for measuring net anaerobic power in exercising horses to allow accurate estimates of total metabolic power. Hypothesis: The increase in VO2max when breathing hyperoxic (HO) gas should be accompanied by a stoichiometrically equal (in terms of ATP turnover, i.e. energy equivalents) decrease in plasma lactate accumulation rate (Mlactate). Methods: Six 3-year-old Thoroughbreds were trained on an equine treadmill wearing a semi-open flow mask for measurement of VO2. After 4 months the horses ran with reproducible specific VO2max (VO2max/kg bwt). The mask design allowed mixing of O2 or N2 with the inward bias flow of gas so that inspired O2 concentration of the horse could be controlled. While the horse breathed either HO (25.1% O2), normoxic (NO, 21% O2) or hypoxic (LO, 19.5% O2) gas, it ran at a speed sufficient to elicit VO2max in NO while jugular venous blood was drawn at 15 sec intervals over a period of 2 min to determine Mlactate. Results: VO2max/kg bwt was not significantly different between LO and NO conditions, and LO data could not be used in the comparison. The VO2max/kg bwt increased from 2.59 ± 0.24 (s.d.) to 2.86 ± 0.24 mlO2 (STPD)/sec/kg in NO and HO, respectively, while Mlactate decreased from 11.5 ± 4.2 to 9.0 ± 3.9 mmol/min as VO2 increased. Conclusions: The ratio of Δ Mlactate to Δ VO2max/kg bwt suggests that Mlactate of approx 11.1 ± 6.7 mmol/min is associated with net anaerobic power approximately equivalent to 1.0 mlO2 (STPD)/sec/kg of aerobic power (20.1 W/kg-1). The high variability in VO2max/kg bwt observed in data from some runs, particularly in LO, suggests that caution must be used when comparing data from the same horse during different runs. Potential relevance: This study provides a tool for estimating net anaerobic power and, more accurately, evaluating total metabolic power of horses exercising at or above their aerobic capacities.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 370-373 |
| Number of pages | 4 |
| Journal | Equine Veterinary Journal |
| Volume | 38 |
| Issue number | SUPPL.36 |
| DOIs | |
| State | Published - Aug 2006 |
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Keywords
- Horse
- Hyperoxia
- Hypoxia
- Lactate
- Oxygen consumption
ASJC Scopus subject areas
- Equine
Cite this
Method for quantifying net anaerobic power in exercising horses. / Ohmura, H.; Hiraga, A.; Jones, James H.
In: Equine Veterinary Journal, Vol. 38, No. SUPPL.36, 08.2006, p. 370-373.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Method for quantifying net anaerobic power in exercising horses
AU - Ohmura, H.
AU - Hiraga, A.
AU - Jones, James H
PY - 2006/8
Y1 - 2006/8
N2 - Reason for performing study: There is no good method for measuring net anaerobic power in exercising horses to allow accurate estimates of total metabolic power. Hypothesis: The increase in VO2max when breathing hyperoxic (HO) gas should be accompanied by a stoichiometrically equal (in terms of ATP turnover, i.e. energy equivalents) decrease in plasma lactate accumulation rate (Mlactate). Methods: Six 3-year-old Thoroughbreds were trained on an equine treadmill wearing a semi-open flow mask for measurement of VO2. After 4 months the horses ran with reproducible specific VO2max (VO2max/kg bwt). The mask design allowed mixing of O2 or N2 with the inward bias flow of gas so that inspired O2 concentration of the horse could be controlled. While the horse breathed either HO (25.1% O2), normoxic (NO, 21% O2) or hypoxic (LO, 19.5% O2) gas, it ran at a speed sufficient to elicit VO2max in NO while jugular venous blood was drawn at 15 sec intervals over a period of 2 min to determine Mlactate. Results: VO2max/kg bwt was not significantly different between LO and NO conditions, and LO data could not be used in the comparison. The VO2max/kg bwt increased from 2.59 ± 0.24 (s.d.) to 2.86 ± 0.24 mlO2 (STPD)/sec/kg in NO and HO, respectively, while Mlactate decreased from 11.5 ± 4.2 to 9.0 ± 3.9 mmol/min as VO2 increased. Conclusions: The ratio of Δ Mlactate to Δ VO2max/kg bwt suggests that Mlactate of approx 11.1 ± 6.7 mmol/min is associated with net anaerobic power approximately equivalent to 1.0 mlO2 (STPD)/sec/kg of aerobic power (20.1 W/kg-1). The high variability in VO2max/kg bwt observed in data from some runs, particularly in LO, suggests that caution must be used when comparing data from the same horse during different runs. Potential relevance: This study provides a tool for estimating net anaerobic power and, more accurately, evaluating total metabolic power of horses exercising at or above their aerobic capacities.
AB - Reason for performing study: There is no good method for measuring net anaerobic power in exercising horses to allow accurate estimates of total metabolic power. Hypothesis: The increase in VO2max when breathing hyperoxic (HO) gas should be accompanied by a stoichiometrically equal (in terms of ATP turnover, i.e. energy equivalents) decrease in plasma lactate accumulation rate (Mlactate). Methods: Six 3-year-old Thoroughbreds were trained on an equine treadmill wearing a semi-open flow mask for measurement of VO2. After 4 months the horses ran with reproducible specific VO2max (VO2max/kg bwt). The mask design allowed mixing of O2 or N2 with the inward bias flow of gas so that inspired O2 concentration of the horse could be controlled. While the horse breathed either HO (25.1% O2), normoxic (NO, 21% O2) or hypoxic (LO, 19.5% O2) gas, it ran at a speed sufficient to elicit VO2max in NO while jugular venous blood was drawn at 15 sec intervals over a period of 2 min to determine Mlactate. Results: VO2max/kg bwt was not significantly different between LO and NO conditions, and LO data could not be used in the comparison. The VO2max/kg bwt increased from 2.59 ± 0.24 (s.d.) to 2.86 ± 0.24 mlO2 (STPD)/sec/kg in NO and HO, respectively, while Mlactate decreased from 11.5 ± 4.2 to 9.0 ± 3.9 mmol/min as VO2 increased. Conclusions: The ratio of Δ Mlactate to Δ VO2max/kg bwt suggests that Mlactate of approx 11.1 ± 6.7 mmol/min is associated with net anaerobic power approximately equivalent to 1.0 mlO2 (STPD)/sec/kg of aerobic power (20.1 W/kg-1). The high variability in VO2max/kg bwt observed in data from some runs, particularly in LO, suggests that caution must be used when comparing data from the same horse during different runs. Potential relevance: This study provides a tool for estimating net anaerobic power and, more accurately, evaluating total metabolic power of horses exercising at or above their aerobic capacities.
KW - Horse
KW - Hyperoxia
KW - Hypoxia
KW - Lactate
KW - Oxygen consumption
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UR - http://www.scopus.com/inward/citedby.url?scp=84878458535&partnerID=8YFLogxK
U2 - 10.1111/j.2042-3306.2006.tb05571.x
DO - 10.1111/j.2042-3306.2006.tb05571.x
M3 - Article
C2 - 17402450
AN - SCOPUS:84878458535
VL - 38
SP - 370
EP - 373
JO - Equine veterinary journal. Supplement
JF - Equine veterinary journal. Supplement
SN - 2042-3306
IS - SUPPL.36
ER -