Even sets of repetitions of each with a weight appropriate for your strength will be good for you and tone you up! 둘째 날 B는 허리와 다리를 위한 운동 저도 알지만 어딘가에 다리를 넣어야 해서 이렇게 직접 해봤어요! There are a few basic exercises you can do for your back.