The Bruce treadmill protocol: does walking or running during the fourth stage alter oxygen consumption values?

摘要

Objective. To investigate heart rate (HR) and relative oxygen consumption (VO_2) measures during two modes (walking or running stage four) of the Bruce treadmill protocol. Participants. Male volunteers (n=27), ranging in age from 25 to 56 years (M=39.1±10.7 yrs). Experimental design. S's performed to volitional fatigue on the two randomly assigned treadmill tests. Measures. HR and VO_2 were taken each minute and at point of exhaustion. Results. Dependent "t"-tests revealed a significant (p ≤ 0.05) difference between the protocols at 11 minutes (running= 46.7±3.9 > walking=44.6±3.7 ml[kg·min~(-1)]) and at 12 minutes (running=49.3±4.1 > walking=47.6±3.5 ml[kg·min~(-1)]) on the VO_2 values. A significant differences was noted on HR at 11 minutes (running=158.1±13.5 > walking=156.0±13.0 bpm) and at 12 minutes (running=160.4±11.0 > walking=157.8±11.4 bpm) between the protocols. The two-way ANOVA technique revealed no significant differences or interactions on VO_2 or HR between younger ( < 45 yrs) and older ( ≥ 45 yrs) subjects during either protocol. A one-way ANCOVA indicated no significant differences between taller and shorter subjects on VO_2 during the fourth stage of the Bruce protocol. The correlations, between the two protocols, for HR were strong but were weaker and inconsistent for VO_2. The repeated measures ANOVA indicated significant within subject variability between test administrations. Conclusions. When testing endurance trained males, modality, age and height are not factors in differences of VO_2 values during the 4th stage of the Bruce treadmill test but learning effect could be.