One of the components of olive oil is tocopherols, that is, vitamin E. Among the effects of vitamin E is its antioxidant action, which is beneficial for male fertility.
High oxidative stress could affect sperm membranes, causing problems in function. In addition, oxidative stress has also been linked to decreased sperm motility. Therefore, vitamin E and its anti-oxidants action will improve sperm motility.
Moreover, the vitamin E in olive oil has also been linked to the production of the male hormone testosterone.