Originally Posted by New Daddy
By the way, I don't think long distance is good for tennis. Long distance and tennis use muscles totally differently. Judging from the body build of top tennis players, tennis is probably close to short-to-medium distance running (long distance=thin, lean; sprinter=muscular). Actually, this goes to the very topic that I wanted to raise in my OP.
A lot of this will have to do with your pacing on your runs and how you train. It's very different to just simply run 6 miles (is that long distance) "once in a while" at a pace you feel "comfortable", but quite another to train to run a 10K in 40 minutes for example (6:30 pace) or faster, by doing a combination of training (slower stamina runs, pacing runs, and hard track intervals). I’m also confident that if a person could run a marathon in under 3-hours (6:52 pace), they wouldn’t think this wasn’t good for their tennis or made them slow on the court. Exactly the opposite.
As is often the case, the devil is in the details. I think many, many different training plans can get you "tennis fit".