Anecdotally, shilajit has been reported to improve energy and endurance; however, this is currently not supported by strong evidence.
In mice, shilajit was found to increase muscle ATP levels,[1] and fulvic acid has been shown to stimulate mitochondrial energy production in vitro.[2] One human clinical trial reported that shilajit supplementation minimized the decline of muscle strength following a fatiguing exercise.[3] Beyond this, the effects of shilajit on exercise performance are entirely unexplored.