One of the reasons for a study by Usaj and Starc (A-21) was an interest in the behavior of pH kinetics during conditions of long-term endurance and short-term endurance among healthy runners. The nine subjects participating in the study were marathon runners aged 26 5 years. The authors report that they obtained a good correlation between pH kinetics and both short-term and long-term endurance.

The following are the short- (VSE) and long-term (VLE) speeds and blood pH measurements for the participating subjects.

VLE VSE pH Range 5.4 5.6 .083 4.75 5.1 .1 4.6 4.6 .021 4.6 5 .065 4.55 4.9 .056 4.4 4.6 .01 4.4 4.9 .058 4.2 4.4 .013 4.2 4.5 .03 Source: Data provided courtesy of Anton Usaj, Ph.D.