i know this is a very hot topic with differing opinions but although sprint training and any running with quick, powerful bursts is beneficial for pitchers what about distance running and the effect it has on stamina? id have to imagine better stamina would allow you to keep peak performance in the later innings of starts…
Stamina is used too broadly in this case. When you run for long distance the “stamina” that you are building is aerobic. Baseball doesnt involve the aerobic energy system, it instead uses the anaerobic. Anaerobic energy is based off of short, explosive movements. If you want to increase stamina in this area, you would look to increase muscular endurance (power endurance is a more accurate name for it), as you are going through a short but explosive movement (the pitch) followed by a period of rest as you get the ball back, take the signs and then repeat. An inning can range from 10-30 pitches, and during the course of a game a pitcher might throw 120 pitches or more (factoring in bullpen warmups, etc).
So the real issue is conditioning your power endurance to avoid loss of strength as the game wears on. You can acheive this by mimicking the conditions of a game - one explosive rep, followed by a short rest, then going again. Exercises can vary, but explosiveness is key and you want to incorporate as many of the “prime movers” as possible. One such exercise would be powercleans (or variations) done with 50% of your max weight, completing 20 repetitions. Another option would be to split exercises into a small circuit format, linking them back to back. An example would something like, 10 box jumps, 12 med ball slams, 10 powercleans. Again, you want the exercises to match the pace of your sport, so you would do one rep with max effort, then pause and reset to go again.
If you consider each set, either the small circuit or the high reps of a single exercise, to roughly equate to an inning, then you can see how the fatigue begins to mount. Even if you rest 5-7 minutes between sets, there is still going to be some residual fatigue as you continue on through the workout. Building your anaerobic endurance in this manner will directly transfer to pitching stamina, long distance running won’t.