Parameters:
(1) weight lifted in pounds
(2) number of repetitions
estimated 1-RM in pounds =
= (weight lifted) * (1 + (0.025 * (number of repetitions)))
fraction of 1-RM =
= 1 / (1 + (0.025 * (number of repetitions)))
In addition, the authors give the number of repetitions that should be given at a percent of 1-RM. When solved this is.
number of repetitions at a percent of 1-RM =
= 40 * (1 - ((weight used) / (1RM))) =
= 40 * (1 - (fraction of 1RM))
If this is rearranged the first equation should be:
estimated 1-RM in pounds =
= (weight lifted) / (1 - (0.025 * (number of repetitions)))
which is similar to the equation of Lander from 1985.
