What would be the best body hair trimmer for guys?

I play varsity tennis at my school and my legs are quite hairy. My coach told me that I should get a body hair trimmed so that I would run faster. This is really confusing as how would this help since it is not swimming but I have to listen to my coach and do it. So I am looking for some effective and best body hair trimmer for guy’s hair. Can anyone help? What would be the best body hair trimmer for guys? I would really appreciate your reply at the earliest. Thanks.