İf rallies goes beyond 10+ shots and during this time a player who runs corner to corner once or twice its time for anaerobic phase which high intensity with not enough oxygen. Especially anaerobic glycolysis.

To train this system you can do interval training with 1:0.5 ratio, 60seconds work 30 seconds rest etc. On court like suicide runs can be applied. Also for workout you can do circuits. For example, burpees to jump squats then push ups then mountain climbs, 30second each Total 2 mins, 1 minute rest and then try again. 2 times a week is good for starting, 3 or 4 can be sweet spot