Wow.
I'm not even through the first page of responses and I have to get involved.
Let me first say, I am very wary of pitching instructors, especially those selling something. Especially an increase in velocity. It is my opinion that other than a year round schedule, it is no accident that every kid can hop on the internet and get 5 different guys pushing some kind of system to increase their velocity and suddenly 10 years ago, Tommy John surgery and injuries start to skyrocket.
@JH, You can make a scientific study say anything you like. I am also the cross country coach for our high school, running in general helps overall conditioning so I 100% completely disagree. This does not however mean that my pitchers run 3 miles a day at practice. Pitching is using fast twitch muscles, running doesn't but does help keep you in shape. Running in general strengthens your core, which is extremely important for pitcher. We have several cross country runners who were by far our best pitchers and a couple of years ago maybe the top pitcher in the district was a runner.
You also mentioned ice being bad. I've read that study with my school's very good trainer and she laughed.
Weighted baseballs are useless. We had a nearby coach, go through one of the programs with weighted balls and it caused problems and only half of his kids gained any velocity. The other half had injury issues.
So, you can make a scientific study say anything you like? Not really. You, instead would just take the word of your schools "very good trainer" as the definitive word on icing and ONE coach's experience with weighted balls in ONE program as the definitve answer on weighted balls? I think I'll ignore your trainer and go with the science and I'll ignore your one weighted ball study and go with both my experience and the experience of several other credible coaches who have had fantastic velocity increases with weighted balls. As to long distance running, I'll likewise go with those pesky scientific studies.