Predicting maximal strength in trained postmenopausal woman

Area of Science:

• Exercise Physiology
• Gerontology
• Biomechanics

Background:

• Estimating one-repetition maximum (1RM) is crucial for resistance training prescription.
• Previous methods for 1RM prediction may lack accuracy across diverse repetition ranges and exercises.
• Postmenopausal women represent a key demographic for strength assessment and training optimization.

Purpose of the Study:

• To develop and validate an equation for predicting 1RM from repetitions to fatigue (RTF) in postmenopausal women.
• To assess the equation's accuracy across four different machine resistance exercises.
• To determine if the prediction equation is independent of exercise type and RTF.

Main Methods:

• Seventy trained postmenopausal women (mean age 57.4 years) participated.
• Participants performed maximal and submaximal repetitions (3-20RM range) on leg press, bench press, rowing, and leg adduction machines.
• A cubic polynomial equation was derived to predict 1RM from RTF, maintaining consistent test execution.

Main Results:

• The cubic polynomial equation accurately predicted 1RM from RTF with mean absolute differences of 1.5-3.1% across the four exercises.
• Coefficients of variation for the predicted 1RM were consistently below 3.3%.
• The equation's accuracy was not influenced by the specific exercise or the number of repetitions performed to fatigue.

Conclusions:

• The developed equation provides a valid and accurate method for estimating 1RM in trained postmenopausal women using RTF.
• This approach is reliable across a wide spectrum of repetitions and different machine-based resistance exercises.
• Repetitions to fatigue can be effectively utilized to estimate 1RM, simplifying strength assessment in this population.