XXXX and gas exchange responses to incremental and steady state running.

@entity1576 @entity26 @entity880 @entity4962
This study compared the @entity26 uptake ( @entity4962 ) and running velocity at which the @entity880 threshold (LT), the @entity1576 ( @entity1576 ), and the maximal @entity880 steady state (MSSLA), and the maximal @entity4962 steady state (MSSVO2) occurred in 11 trained male runners (mean age = 22.4 years, range 18-28 years). Each underwent an incremental treadmill test to exhaustion. The LT was defined by a systematic, continuous increase in arterialised venous blood @entity880 ; the @entity1576 was determined by an abrupt rise in VE. @entity4962 (-1) without an increase in VE.VCO2(-1). Each subject also completed a series of steady state treadmill runs of 20 minutes duration. The MSSLA was determined as the highest velocity and @entity4962 at which @entity880 concentration increased by less than 0.2 mmol.l-1 from minute 10 to minute 20. The MSSVO2 was determined as the highest velocity or @entity4962 at which a steady state in @entity4962 was not delayed for more than 3 minutes (with a steady state defined as @entity4962 within 0.2 l.min-1 of the average @entity4962 over the last 10 minutes of each test). Each subject also completed a 5 km time trial run to assess performance. No significant differences were found among the four variables expressed either as @entity4962 or velocity. Significant correlations were found between MSSLA and MSSVO2 (r = 0.74) expressed as @entity4962 , and between MSSLA and MSSVO2 (r = 0.90), MSSVO2 and @entity1576 (r = 0.70) and MSSLA and @entity1576 (r = 0.67) expressed as velocity. A stepwise regression analysis found MSSLA (expressed as velocity) to be the best predictor of 5 km performance (r = 0.87). It was concluded that (a) MSSLA and MSSVO2 are closely related, and (b) MSSLA is a good predictor of performance and may be an important, objective measure of cardiorespiratory endurance capacity.
