Lower limb suspension induces threshold-specific alterations of motor units properties that are reversed by active recovery

•Little is known about the consequences of disuse on the neural control of large muscles and how these can be reversed.•We studied changes in motor units properties in the vastus lateralis muscle after 10 days of unilateral lower limb suspension and after 21 days of active recovery.•A short period of muscle unloading reduces the discharge rate of lower- but not of higher-threshold motor units, suggesting a preferential impact of disuse on motoneurons with a lower depolarization threshold.•The restoration of neural control requires about twice the duration of the disuse period.