Is playing baseball year round bad for a young pitcher?
Year-round competitive pitching is a well-established injury risk, and MLB and USA Baseball recommend at least four months off from competitive pitching annually. Total cessation of all throwing is a separate question. Connective tissue that rests without any stress reorganizes disorganized, which is why many arms fail shortly after throwing resumes rather than during the season.
The short answer, and the question hiding inside it
Year-round competitive baseball is bad for a young pitcher. The evidence on that is about as settled as anything in this sport. MLB and USA Baseball recommend at least four months a year away from competitive pitching, with two to three of those months continuous and free of overhead throwing altogether. Take that seriously.
There is a second question inside the first one, though, and it is the one almost nobody asks. Taking a young pitcher off the mound and turning his arm off entirely are not the same decision, and only one of them is well supported.
What happens during a total shutdown
Picture the standard version. He throws his last pitch of the season, cleans out his locker, and does not touch a baseball for three months.
He has just spent seven or eight months putting microscopic trauma into every piece of connective tissue in that arm. Now it begins healing, with no stress on it at all.
Connective tissue organizes itself along the lines of force it is asked to handle. It gets that organization from being loaded while it heals. Remove the load entirely and the repair lays down without direction, which leaves a patch that is strong in no particular orientation.
Then February arrives and he starts throwing again. That disorganized tissue is the most vulnerable it will ever be, and it is being loaded. Part of the wave of arm injuries every spring is not about spring at all. It is about what the winter did.
The third way
Off-ramp rather than stopping cold. Taper him down. A few weeks of easy bullpens and light long toss after the season ends, with intensity dropping gradually. That allows new tissue to form along functional lines instead of randomly.
Keep a low-intensity maintenance thread through the winter. Not a program and not competition. Sub-maximal, throwing-like movement that keeps tissue organized. He is completely off competitive pitching. His arm is not completely idle.
When he ramps back up in the spring, his connective tissue is already organized. He gets a rolling start rather than starting from a dead stop.
The rule that saves the most arms
Every week of complete rest requires roughly two weeks of ramping back up.
The pattern we see every year is not caused by rest. It is caused by what follows rest. An athlete takes too long off, starts back too late, and then has to rush to be ready for tryouts or a first tournament. If he takes ten weeks completely off, he needs something like twenty weeks to return properly. When the calendar does not allow for that, the calendar is the thing that has to change.
What to do
- Pull him out of year-round competitive pitching. Four months minimum, two to three of them continuous.
- Taper into the off-season rather than stopping on a single day.
- Keep light, sub-maximal throwing-like movement through the winter.
- Count backward from the first game he needs to be ready for, using two weeks of ramp for every week he was down.
- Use the months off for the things the season never allows: movement quality, strength, sleep, and general athleticism.