I don’t mean to ruffle any feathers, but I most likely will.
One of the things I keep telling my son is he has a big advantage over other kids playing baseball. That’s because I never really played baseball so I had nothing from 35 years ago to teach him. I went out and did research on everything having to do with baseball so it was all the latest information from the latest research. I learned very quickly not to trust “conventional baseball wisdom” because it was wrong most of the time. So I started seeking out conditioning people that had a “CSCS” after there name (certified strength and conditioning specialist). I found the website for Dana Cavalea, CSCS who is the strength and conditioning coordinator for the New York Yankees and Steve Zawrotny, MS, CSCS and his website
www.baseballfit.com and others. I also discovered Velocity Sports Performance and yes the trainers there all have CSCS after their names. The main question always asked by these trainers was “Why train aerobically for an anaerobic sport?”
The other main saying that always came up “Train slow to be slow, train fast to be fast”.
Most of the baseball coaches (not all) coach the way they were taught 30+ years ago and their coaches coach that way because that’s the way they were coached 30+ years ago and so on and so on. So a lot of the techniques used for training in baseball today could be 100 years old. It wasn’t that long ago that it was “conventional baseball wisdom” to tell baseball players to never left weights.
Distance running will slow you down and in order to tap into your aerobic conditioning you have to do an action continuously for at least 2 minutes. No play lasts 2 minutes in baseball. Even the pitcher is at rest over 90% of the time. Interval training will give the endurance that is needed without slowing the player down.
I know it’s much more complex than this but simply put, there are three main types of muscles: fast twitch, slow twitch and a transitional type (many more types, but this simplifies the subject). Transitional types will take on the characteristics of the fast twitch or slow twitch depending on how they are trained.
I could go on and on but the bottom line is, if your players run a lot of distance they will become slower sprinters and it will take away from their quickness.