Ok geniuses. There is no answer for this. It's still debatable as to even how youre supposed to measure caloric consumption by the human body. Every persons metabolic rate is different.
We know how much energy is in a "calorie" (which is a kilo calorie in human terms) but that's about it. We dont know how many calories you burn while you just sit there. We certainly dont know how many calories you burn while you're engaged in something as dynamic as tennis.
There is no way to tell how much calories are burned by the body at any one time. There is only just a guess.
We cant even tell you what your BMI is with much certainty. BMI is just an approximate guess, much like "calorie counters".
We know within a few kcal how much kcals are in the prepackaged food that we eat. That is a far cry from "how many hours of what exercise" it will take for our body to consume enough calories we absorbed from that food.
"In the 1980's two men dominated--sometimes each other, most of the time everyone else."