Abstract
AbstractThis study investigated how equipment and sex affect the prediction accuracy of
the maximum number of repetitions performed to failure (RTF) using the fastest
mean velocity of the set (MVfastest). Sixteen men and twelve women
completed four sessions (two using free-weight equipment and two sessions using
the Smith machine). Each session involved three sets of repetitions to failure
against the 65%, 75%, and 85% of the one-repetition maximum, interspersed by
10-min of rest. The goodness-of-fit of the individualized
RTF-MVfastest relationships was comparable between both equipment
types and sexes (P≥0.510). Moreover, there were not significant
differences in the MVfastest associated with RTF between equipment
types (P≥0.258). However, the MVfastest associated with RTF
was higher for men than for women in repetitions 6 to 15 (P≤0.043;
ES≥0.69). In addition, the absolute errors when predicting RTF showed no
significant differences between equipment types and loads (P<0.444).
Specifically, these RTF estimates were within an acceptable range for men (<2
repetitions), but not for women (≥2 repetitions) (main effect of sex:
P≤0.018; ES≥0.58). These findings suggest that individualized
RTF-MVfastest equations estimate the RTF with an acceptable
precision in men during bench press exercises in both equipment types but
exhibit lower precision for women.