One of the most common things we hear from baseball players is: 'My arm was fine, then suddenly it started hurting.'

Many players instinctively try to trace arm pain back to one session: a bad outing, or a pitch that didn't feel right, and sometimes there’s a clear event behind it. But more often, what looked sudden was actually 3–4 weeks of ‘building it up’ until you reached the threshold

It might have started with some extra throwing sessions, followed by a tournament weekend, then a few extra bullpens and some throwing at home. Nothing that seemed excessive at the time, but your arm was quietly accumulating that load the whole time.

This is what we refer to as the workload trap.

Your arm is keeping score

It’s easy to think about workload in terms of games and pitch counts, but your arm doesn’t know whether a throw happened in a game, at training, in a bullpen or in the backyard. It simply responds to the total amount of throwing it’s being asked to handle.

Research has shown that official pitch counts can substantially underestimate how much throwing a pitcher completes in any given week. 

So, the question you should be asking isn’t ‘how many pitches did I throw on game day?’ but ‘how much total throwing is my arm actually doing?’

The throwing workload trap

When your arm is asked to adapt to more work than it’s used to, like at the start of a season or when returning from injury, it needs time to adapt.

Thing is, soft tissue adaptation is slow – your shoulder and elbow need 2–4 weeks to properly adjust to a new load level before you push further. Most players (and most throwing or arm care programs) don't account for this. Even increasing your throwing totals each week can be overkill.

The challenge isn't training harder – it's recognising the signs of accumulation before it becomes a problem. Which is tougher than it sounds when you're performing well. But issues that may be building behind the scenes will show up eventually, and often at the worst possible time.

The technical term for this is acute-on-chronic workload. There’s a proven clinical association between increased workload and arm fatigue, pain, and throwing-related injuries – though there’s no single workload number that applies safely to every pitcher.

What should you track?

You don’t need to record every single throw. Start with your higher-intensity throwing:

• Games
• Bullpens
• High-intensity throwing at training
• Long toss
• Extra throwing outside team sessions

After a couple of weeks, patterns start to emerge. Even two weeks of data should show up things that weren't visible when you were simply judging how your arm felt each day.

For players: pay attention to how your arm responds. Is it taking longer to recover than usual? Does it feel unusually heavy? Are you noticing changes in velocity or control?

For parents: keep an eye on all their throwing and related activity. Each piece might be reasonable on its own; the issue is when it quietly builds.

For coaches: think about the load you don’t see. You see them at games and training, but not at school or home. Ask your players what else they do each week and make sure they understand the connection.

Start by tracking your throwing workload

We put together a free Throwing Workload Tracker to help you keep tabs on your higher-intensity throwing, so you have a clear picture of what’s happening across the week.

It takes around two minutes to update after a session, and will give you a clearer picture of what your arm is being asked to handle.

Any questions? Drop us a line or check out our complete Arm Care program for baseball players – it's for players of every age and stage who want to build a strong, resilient arm, and avoid unnecessary injuries.