"restore strength" is a correct and usable phrase in written English.
You can use it when describing the process of rebuilding or revitalizing strength or energy in something or someone, such as "The energy drinks helped to restore strength to my tired muscles."
He lifted weights to restore strength to the shoulder and came to spring training healthy.
Muscular exertion seems to exacerbate symptoms, but rest helps restore strength.
Treatment of these generally involves immobilization of the elbow in a flexed position until damage has healed, followed by a graded exercise program to restore strength.
An alternative is the bonding of composite patches, like carbon fibre reinforced epoxy, over cracked or corroded sections to restore strength or stiffness.
Although they reputedly restore strength and bolster male virility – popular varieties include doh mai roo lom ("never go down") and kamlung seua khrong ("strength of a tiger") – they tend to leave inexperienced imbibers with a particularly soul-crushing hangover.
Back on terra firma, and due to arrive in Houston late on Wednesday night, Kelly now faces a month of formal rehabilitation to restore strength to his muscles, calcium to his bones, and a sense of balance to his body.
Addressing this challenge is critical to restoring strength in our polity.
Restoring strength and mobility to your new joint is essential following a total knee replacement, known as knee arthroplasty.
It was the farmers of the socialist kibbutzim who came to symbolize the restored strength of the Jewish people.
Cosgrove, B. D. et al. Rejuvenation of the muscle stem cell population restores strength to injured aged muscles.
China followed up on this action almost immediately with a series of gestures that seemed designed to demonstrate its restored strength to its southern neighbours.
