Sperm quality is often thought to be reflected in semen volume – that is, the amount of semen a man produces during ejaculation. The logic behind this belief is that more sperm must equate to better quality sperm. However, this isn’t necessarily the case. While it’s true that a man’s sperm count (the number of sperm per mm of semen) does affect his fertility, other factors such as motility (the percentage of sperm that swims) and morphology (the percentage of normally-formed sperm) are far more important. In fact, a recent study found that men with higher semen volumes actually had lower concentrations of normally-formed sperm. So while more semen may mean a higher sperm count, it doesn’t guarantee better quality sperm.