A novel scale to assess resistance-exercise effort

Area of Science:

• Exercise Physiology
• Sports Science
• Biomechanical Analysis

Background:

• Assessing resistance-exercise intensity is crucial for effective training.
• Subjective measures like Rating of Perceived Exertion (RPE) have limitations.
• A valid scale to estimate repetitions to failure is needed for exercise prescription.

Purpose of the Study:

• To examine the validity and reliability of a novel subjective scale for estimating repetitions to failure.
• To compare the novel scale with the traditional RPE scale in assessing resistance-exercise effort.
• To determine the efficacy of the new scale in predicting muscular failure during resistance training.

Main Methods:

• Seventeen male bodybuilders performed 5 sets of 10 repetitions at 70% of one-repetition maximum for bench press and squat.
• Participants used a novel estimated-repetitions-to-failure scale and RPE after each set.
• Actual repetitions to failure were recorded to validate the subjective scales.

Main Results:

• High correlations (r ≥ 0.93) were found between estimated- and actual-repetitions-to-failure for both exercises.
• The estimated-repetitions-to-failure scale reliably predicted repetitions to failure, especially in later sets.
• RPE showed high correlation with actual repetitions but did not consistently indicate maximal effort at fatigue.

Conclusions:

• The novel estimated-repetitions-to-failure scale is a valid and reliable tool for predicting muscular failure in resistance exercise.
• This scale can be effectively used for assessing exercise effort and prescribing training intensity.
• The scale offers a more precise method for monitoring training progression compared to RPE alone.