He has a robust physique.
This desk is sturdy and will last a long time.
頑健 describes someone as robust and physically tough, contrasting with 虚弱's sense of frailty.
unparalleled robustness; exceptionally robust health
Compound of 頑 (stubborn, firm) and 健 (healthy, strong). The exact historical derivation is uncertain, but the kanji combination conveys the idea of robust health or sturdiness.