I know its splitting hairs but you really don’t produce lactic acid, you produce lactate. The decrease in muscle pH is due to lack of oxygen to shuttle the hydrogen ions into the mitochondria during intense physical efforts. The decrease in pH is associated with lactate threshold which is one of the main makers of shifting from aerobic to anaerobic energy systems. The only way to really solve the problem is fitness. Training helps you deliver oxygen to your working muscles so you are using aerobic energy systems at a higher percentage of your VO2 max. Intervals are the best way to accomplish this so embrace high intensity flat land sprints and enjoy your hill repeats.