wearing — causing one to become tired; exhausting

a hiker struggles up a rocky mountain trail, wiping sweat from their forehead with heavy breathing. Their backpack weighs them down as they take slow, labored steps on the steep incline. The long uphill climb has drained their energy after hours of continuous walking. Their legs shake slightly and shoulders slump forward from exhaustion. A fellow hiker behind them also shows signs of fatigue, pausing to catch their breath. Another more experienced hiker ahead looks back with concern at their struggling pace. the physically wearing nature of the demanding mountain climb