Having developed my dynamism through studying abroad and my physical strength through school club activities, the spirit of cooperation is my strong point.
「Having...」=「Because I have...」
「Having developed my dynamism through studying abroad and my physical strength through school club activities,...」
ポイント:「having developed」は一回だけ使いました。同じ言葉使う場合で、よく2回目をスキップします。