In this activity, students perform a lateral arm raise and use the information to calculate their one repetition maximum (1RM). The accompanying calculator uses seven different prediction equations.

By the end of this activity, students should be able to:

  • collect and use data with a 1RM predictor calculator
  • discuss why it is safer to estimate 1RM than to measure the value directly discuss the benefits of calculating their 1RM for various strength movements.

Download the Word file (see link below) for:

  • introduction/background notes
  • what you need
  • what to do
  • extension idea.

Download the Excel file for the 1RM predictor calculator (see link below).

Nature of science

Scientists often use mathematical models to help make predictions. All models have limitations but can produce quite accurate results. Read more about this here.

    Published 21 June 2007, Updated 22 November 2013