In practice, the Bruce protocol is the most commonly used treadmill protocol to assess maximal oxygen consumption ([Latin small letter v with dot above]O2max). It has been suggested that a running protocol (e.g., Astrand) may elicit a comparatively higher [Latin small letter v with dot above]O2max and different cardiorespiratory responses when applied to moderately trained runners. Thus, the purpose of this study was to compare [Latin small letter v with dot above]O2max and other cardiorespiratory responses as elicited by the standard Bruce and a modified Astrand treadmill protocol in moderately trained runners. Fifteen women (age = 21 years, height = 171.5 cm, weight = 63 kg, and body fat = 18%) and 15 men (age = 26 years, height = 177 cm, weight = 72 kg, and body fat = 9%) who were moderately trained runners completed a standard Bruce and modified Astrand protocol (random order), separated by approximately 7 days. Heart rate, Borg ratings of perceived exertion, blood pressure, and pulmonary gas exchange variables were measured during the exercise tests using standard laboratory procedures. This study revealed that [Latin small letter v with dot above]O2max values between the Bruce protocol (51.3 +/- 11.6 ml[middle dot]kg-1[middle dot]min-1) and modified Astrand (51.5 +/- 10.9 ml[middle dot]kg-1[middle dot]min-1) were not significantly different in either the men or the women. However, the Bruce protocol elicited significantly higher maximum treadmill time in men and maximum respiratory exchange ratio (RERmax) and maximum minute ventilation (VEmax) values in both genders. Conversely, the modified Astrand elicited a higher HRmax. These data suggest that [Latin small letter v with dot above]O2max in both moderately trained men and women runners is independent of treadmill protocol despite differences in HRmax, RERmax, and VEmax.
(C) 2007 National Strength and Conditioning Association