If you've lifted weights before, it doesn't make a difference in how your muscles rebuild blood vessels during rest and recovery after not using them, compared to someone who hasn't trained before.

What we've found so far is that prior resistance training does not appear to affect how blood vessels in muscles rebuild during periods of disuse and recovery in young adults. Our analysis of the available evidence suggests this outcome, based on what we've reviewed to date. We looked at one key assertion from the research, which states that having a history of weight training doesn’t change how muscle blood vessels respond when muscles are rested or recovering from inactivity, compared to those without prior training [1]. This assertion is supported by 38.0 studies or data points, with no studies refuting it [1]. That means, according to the evidence we’ve analyzed, whether someone has lifted weights before or not, their muscles show similar patterns in blood vessel changes during rest and recovery phases. We don’t yet know why this is the case, and the evidence doesn’t tell us whether other factors—like age, training intensity, or length of inactivity—might influence these results. Our current analysis is limited to young adults, so we can’t say if the same would hold true for older individuals. Also, while the evidence leans toward no difference, we’re still building our understanding, and future studies could add new insights. The takeaway: For young adults, having a history of resistance training doesn’t seem to give an edge—or a disadvantage—when it comes to how blood vessels in muscles respond during rest and recovery after not being used. Whether you’ve trained before or not, your body may handle this process in a similar way—for now, that’s what the data we’ve reviewed suggests.