Validity and reliability of SEIS-3: An instrument for subjective measuring of strength in older adults.

The use of rating of perceived exertion (RPE) has grown substantially, providing a valuable alternative for exercise intensity monitoring, especially for older adults. However, some challenges, such as cross-cultural validity, age-related differences, and reliability issues, necessitate the development of a concise and user-friendly RPE instrument, particularly for strength training in this population. This study aimed to validate the Subjective Effort Induction Scale (SEIS-3), a simplified tool for measuring effort during strength training.