The relationship of individual anaerobic thresholds to total, alactic and lactic oxygen debts after a set treadmill run.

Abstract

This study investigated the relationship of individual anaerobic thresholds to oxygen debt. Anaerobic threshold speed (VTAM) was determined for 21 male university students using a continuous ramp treadmill protocol. The onset of anaerobiosis was determined by visual inspection of excess CO2 elimination. The following week, all subjects ran at the treadmill speed 3.3 m.sec-1 for 10 minutes (this speed split the group into two halves). Recovery oxygen consumption was monitored after this run. Application of double exponential equations by computer and subsequent integration was used to calculate total, alactic, and lactic oxygen debts. Subjects who ran above their VTAM (group L-VTAM) had significantly (p less than .05) higher total, lactic and alactic debts compared to subjects who ran below their VTAM (group H-VTAM). The total debt demonstrated a significant (p less than .05) negative correlation (r = .77) to VTAM in group L-VTAM. This appears to be due to increasing lactic debt, that was also significantly (p less than .05) negatively correlated (r = -.73) to VTAM. Group H-VTAM did not exhibit this characteristic. This study demonstrates that VTAM, as determined by excess CO2 elimination, is a critical factor in determining oxygen debt and therefore, work above this point (which results in the onset of metabolic acidosis) may limit the optimal running speed for a given distance.