This study compared measurements which were considered traditionally to reflect alactacid and lactacid components of anaerobic metabolism. Subjects (men (N = 9) and women (N = 5)) on one occasion performed an exhaustive cycle ergometer ride at VO2 max and had peak lactate and O2 debt (fast and slow components) determined. On a second occasion, they performed a Wingate test. All data were normalized for body weight. Very few correlations were found between O2 debt or peak lactate and the peak power, mean power and power decrease of the Wingate test. In particular, both peak lactate and the fast O2 debt component had low, nonsignificant correlations with either peak or mean power. The study failed to support the traditional assumptions that both tests are quantifying the same anaerobic energy systems.