A scoping review of muscle excitation in resistance training across key training parameters

Resistance training is widely recognized for its health and performance benefits. Since muscle activation correlates with muscle strength and performance, optimizing training variables to maximize activation during resistance training exercises is of interest. However, the most effective approach remains debated. This scoping review examines the impact of training variables such as intensity, range of motion (ROM), and repetition duration on muscle excitation, measured via surface electromyography (sEMG), in healthy, pain-free adults (≥18 years). Only original research in English was considered, focusing on acute bipolar sEMG assessments. A systematic search of PubMed, Scopus, and Web of Science identified 63 studies (35 on intensity, 13 on ROM, 15 on repetition duration) involving 966 participants. The findings indicate that higher training intensities generally produce greater sEMG signals. In addition, faster repetition durations are linked to increased muscle excitation, and greater ROM enhances excitation when repetition speed is controlled. However, when velocity is not standardized, ROM findings remain inconsistent. The current evidence suggests that higher intensity and faster repetitions increase muscle activation, while the effects of ROM remain unclear. Future research should focus on addressing these gaps and improving the experimental design to better understand the interplay of these training variables on muscle excitation.