hi ok as sperm grows inside your testes it just keeps moving through and the old sperm just enters your body its like an on going thing. but masturbating once a week does not hurt this helps us men to keep things moving as you seem to be worried about your sperm freshness as does sex on a regular basis say twice a week. do hope this helps you. good luck
does it make a difference how long it's been since last ejaculation? does sperm have to be kept fresh to be fertile?