This is just one more of many case studies from the US National Library of Medicine - National Institutes of Health which proves that pitchers will benefit from heavy resistance training. Not only does heavy resistance training increase pitching velocity and reduce pitching injury but it also enhances endurance.
The Department of Physical Education, University of Illinois, Chicago put together a study to prove the Potential for strength and endurance training to amplify endurance performance. Here are the results from the study:
These data do not demonstrate any negative performance effects of adding heavy-resistance training to ongoing endurance-training regimens. They indicate that certain types of endurance performance, particularly those requiring fast-twitch fiber recruitment, can be improved by strength-training supplementation.
Not only does this study prove the performance benefits of heavy resistance strength training with endurance athletes but it specifically states that it is even more beneficial for those performances that require fast-twitch muscle fiber recruitment. I couldn't think of any better performance than power pitching when it comes to endurance and fast-twitch muscle fiber recruitment. The shoulder rotation speeds of the hardest pitchers in the game is proven to be the fastest body movements of all sports in the world.
This study also indicates that some type of strength-training supplementation should be occurring in-season to improve performance. This is the case because the study used a group of trained endurance athletes who were already at a steady-state level of performance when they instituted a heavy-resistance training program that was 3 days a week while endurance training remained constant.
How to Amplify Endurance Pitching Performance
The case study does not describe the heavy-resistance training program the athletes used for the study. It does state that the program was 3 days a week for 10 weeks straight and that the training routine was focused in the legs as the case study states that "leg strength was increased by an average of 30%." A predominantly leg focused heavy-resistance training program would make sense for the study because the endurance athletes they were testing were cyclists.
This roughly means the athletes where using some type of heavy-resistance training on the legs which was close to or more than their body weight, 3 days a week. This should tell all pitchers, who want to amplify their endurance so they can throw 7 innings of shutout baseball instead of 5, that they need to add some heavy-resistance training mainly on the legs when in-season. It is important to understand that heavy-resistance training is important during all seasons of training but this study is proof that in-season should be no exception. Not only will the added heavy-resistance training amplify endurance in-season but it will also help maintain the strength gains made from the off-season which will both help prevent velocity inconsistencies and loss.
If you are looking for a program that implements heavy-resistance training to amplify endurance in-season then checkout the 3X Pre and In-Season programs. These programs also include in-season throwing drills to support the 3X mechanics along with flexibility, core, joint integrity routines and much more.