A recent study investigated the effects of daily quercetin glycoside supplementation on muscle strength and motor unit (MU) behavior in healthy older adults undergoing a six-week resistance training program. The study included 26 participants divided into two groups: one receiving 200 mg/day of quercetin glycosides (QUE group) and the other a placebo (PLA group). Both groups experienced significant increases in maximal voluntary force (MVF) during isometric knee extension exercises, with the QUE group showing a greater improvement (approximately 15%) compared to the PLA group (about 5%). While muscle mass remained unchanged in both groups, the QUE group exhibited higher firing rates in MUs with moderate to higher recruitment thresholds. Additionally, a significant correlation was observed between the percentage change in MVF and the percentage change in firing rates of higher-threshold MUs. These findings suggest that quercetin supplementation enhances the activation of higher-threshold MUs, leading to greater improvements in muscle strength among older adults engaged in resistance training.
Source: https://link.springer.com/article/10.1007/s00394-025-03634-9
