I lot of factors enter into calorie burning. For example:
How tough is the match and how much get up and go do you devote to each and every point.
Does your opponent make you run?
But given that it is a 3.5 level; I would say that in singles you may burn 400 calories an hour and in doubles maybe 200.
But as you get better in to the 4.5 and beyond; you opponent can really make you run full blast on almost every point from serve return until the point is concluded. You can burn up to 900 calories easily depend on the temperature - 90 degrees or higher you could easily do 1,200 if you play out of your mind and have an real tough aggressive hitter as an opponent that is doing the same.
Prostaff 6.0 85, Prostaff Tour 90, KProstaff 88 Head Prestige FlexPoint 98, Head Prestige IG Youtek Mid 93.