RPE (Rate of Perceived Exertion) is a method for gauging training intensity based on effort rather than fixed percentages. Training close to failure (RPE 9-10) maximizes muscle growth and strength by recruiting the most muscle fibers. As a coach, I use RPE because it allows for auto-regulation, ensuring clients train effectively without overreliance on rigid numbers. Learning RPE takes practice, but it helps lifters develop awareness, train smarter, and make consistent progress.