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

OBJECTIVE

To investigate heart rate (HR) and relative oxygen consumption (VO2) measures during two modes (walking or running stages 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 VO2 were taken each minute and at point of exhaustion.

RESULTS

Dependent "t"-tests revealed a significantly (p < or = 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 VO2 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 VO2 or HR between younger (< 45 yrs) and older (> or = 45 yrs) subjects during either protocol. A one-way ANCOVA indicated no significant differences between taller and shorter subjects on VO2 during the fourth stage of the Bruce protocol. The correlations, between the two protocols, for HR were strong but were weaker and inconsistent for VO2. 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 VO2 values during the 4th stage of the Bruce treadmill test but learning effect could be.