Study of measurement and experimental design problems associated with the step test

The Harvard Step Test (HST) scoring formula is inadequate when individuals do not complete the prescribed duration. Insull, et al., (1955) proposed a formula with a quadratic function which rendered scores independent of the duration of stepping. Using Insull's data, a linear function was fit to the relationship between the HST score and the duration of stepping, and a new simpler scoring formula was developed. The new scoring formula was evaluated empirically to help an investigator make a choice among different HST scoring formulas. Three maximum stepping durations were administered to 12 subjects previous to and subsequent to running two miles each day for nine days. Compared to the rapid HST scoring formula, the classical HST formula was not consistently more sensitive to the changes produced by the physical conditioning. Both the classical and rapid formulas were less sensitive than the new versions of the two formulas. It was concluded that the controversial nature of the HST is, in part, a result of inconsistent empirical results produced by the original formulas. It was also concluded that the new formulas should always be used in preference to the original formulas, since the new formulas are more sensitive to the changes produced by physical conditioning, and they produce scores which are comparable to the standard HST scores regardless of the duration of stepping. Finally, concurring with past investigators, it was concluded that the extra two pulse counts employed by the classical formula are redundant, thus rendering the rapid formula preferable since it requires less testing time.