I'm not saying how these systems interact because I don't understand them. But there is some information from research on these 3 energy systems. The power or force? and output duration that is required from the muscles determines how the body uses these systems. I'm also sure that they work together, in an overlapping manner. If you have to lunge for a serve your heart & respiration have not changed but the greatest force is supplied apparently by the ATP-CP system. Run for some balls and all the systems are probably contributing.
The average calories per second over a tennis match is probably not very high. The calories per second during some intense points is probably much more than the aerobic system can handle, similar to lifting heavy weights for a few reps.
I was given a VO2max test. As best it was explained to me they keep increasing the resistance on an instrumented pedaling machine to find your aerobic limit. As the resistance goes up you can handle it easily at first. You also slowly fatigue. They are raising the resistance in increments faster than you are fatiguing and so at some point they exceed your aerobic capability. At that point you know you can continue but not for very long - just several more seconds. I believe that at that point your aerobic system was not able to handle the power and that you are then exhausting the last contributions from your fatigued anaerobic energy systems. At that point your heart and respiration rates are very high.
I'm sure this stuff is well researched for many simpler sports such as rowing and running. It would be interesting to see an evaluation for tennis.
Last edited by Chas Tennis; 08-15-2012 at 06:36 AM.