厳しいダイエットの反動で、つい食べ過ぎてしまった。
After my strict diet, I ended up overeating on the rebound.
好景気の反動で、翌年は売り上げが大きく落ち込んだ。
In a backlash to the boom, sales dropped sharply the following year.
厳しく育てられた反動からか、彼は大学に入ると遊んでばかりいた。
Perhaps in reaction to his strict upbringing, he did nothing but play once he got to university.