Perceived Exertion, Neuromuscular Activation, and Training Volume in Older Adults: Validating RPE-1 in Moderate-Velocity Elastic Band Resistance Training.

Accurately monitoring training intensity is essential in older adults to optimize adaptations and reduce injury risk. While the OMNI-Resistance Exercise Scale for elastic bands (OMNI-RES EB) has been validated post-exercise, applying it from the first repetition (RPE-1) may provide a quick, non-invasive method to individualize training without maximal testing-improving prescription accuracy, limiting fatigue, and supporting autoregulation in vulnerable populations. The purpose of this study was to validate RPE-1 during moderate-velocity elastic resistance training in physically active older adults with prior experience using elastic-band exercise, by analyzing its predictive validity, reliability, and neuromuscular and cardiovascular responses across effort levels. # Study type Quasi-experimental cohort study. # Methods A convenience sample of twelve healthy older adults (≥60 years) with >3 months of experience in elastic band resistance training performed standing military press sets to failure with an elastic band at four target RPE-1 levels (2-8 out of 10). The band color was chosen based on the participant's RPE-1 on the first repetition. Neuromuscular activity of the anterior deltoid and triceps brachii was recorded using surface electromyography, and heart rate, blood pressure, and total repetitions were also measured. Inter-session test-retest reliability of RPE-1 was assessed using intraclass correlation coefficients (ICC). Neuromuscular activity progression was examined across the four RPE-1 levels. Concurrent validity was evaluated through the relationship between RPE-1, total repetitions, and physiological responses. # Results Six women and six men volunteered to participate (66.75±3.49 years; BMI: 24.99±4.32 kg/m2). RPE-1 was strongly associated with neuromuscular activation in both the anterior deltoid (p<0.001, ηp²=0.83) and the long head of the triceps brachii (p=0.001, ηp²=0.52), showing a strong linear increase with perceived effort. RPE-1 also predicted total repetitions (r=-0.71; R2=0.50), independently of participants' strength level, measured by handgrip strength. Reliability was high across variables (ICC=0.84-0.94). Cardiovascular responses did not differ significantly between intensities. Neuromuscular activation increased across set segments, with marginal gains beyond 75% of total volume. # Conclusion RPE-1 via the OMNI-RES EB scale is a valid, and reliable tool for regulating elastic resistance training intensity in older adults, enabling early, efficient, and individualized prescription strategies. # Level of evidence 3b.