Tennis is a mix between anaerobic bursts of speed and aerobic movements that last a long time. At the current moment, I'm building a fitness routine for becoming a better tennis player, and want to include 3 days a week of cardio in it. I also do plyometric and weight training two days a week. Between a 3,200 meter run, 5,000 meter run, 10,000 meter run, and upwards, what do you think should be the best one to improve times on? My current 5k record is 24:06, which isn't great but isn't horrible (I still have 20~ pounds to lose for being a better player). Should I focus on improving this time or move on to longer runs?