How Many Athletes Can One Coach Manage? What the Training Data Shows

Simma reads every session a squad records and watches how each athlete's training changes against their own history. That gives us one view of the capacity question, the view from the data, and this piece stays inside it.

The question comes up in almost every conversation we have with a coach, usually as a worry rather than a question: "I could take more on, but something would slip." What follows is what we can see about the something.

What a squad looks like from where we sit

Every week, each athlete on a squad records some number of sessions. Each session arrives as a file: pace or power and heart rate sampled every second, laps or lengths, GPS if it was outdoors, temperature and humidity where and when it happened. One session is a lot of numbers. A squad's week is a lot of sessions.

Nobody reads the raw numbers, and nobody should. What a coach actually wants from that pile is a much shorter list of things: who trained and who did not, whose load is climbing and whose is flat, whose easy sessions have stopped being easy, who has gone quiet against their own pattern, who is carrying three hard sessions in a row without a recovery between them. That list is not coaching. It is the thing coaching starts from.

We call the work of producing that list screening, to keep it separate from what happens next. The distinction matters for the capacity question, because the two kinds of work scale differently.

Screening scales with the squad. Coaching does not have to.

Screening is the same job for every athlete, every week. Read the sessions, compare them with what is normal for this person, decide whether anything has moved. Its cost is roughly linear in the number of athletes: twice the squad, twice the reading. It is also the part that is easy to skip when time is short, because skipping it produces no visible failure that week. The athlete who is quietly falling behind their own rhythm does not send a complaint.

Coaching is not the same job for every athlete. Some weeks most of a squad is fine and needs a sentence. A few athletes need a conversation, and those conversations are where a coach's judgment, memory of the person and relationship do the work. That part does not have to scale with the squad, because it is spent where the screening says to spend it.

So, from the data side, a squad has a ceiling only if screening and coaching are done as one job, by one person, in one sitting. When they are separated, the question changes shape. It stops being "how many athletes can I read?" and becomes "how many of those conversations can I have well?" The data does not answer the second one. That is your number, and it is different for every coach.

What we see happen when screening is skipped

We can say this part with some confidence, because it is the pattern our system was built to catch. When a coach is stretched, the first thing to go is not programming and it is not the athletes who are struggling loudly. It is the quiet ones.

An athlete whose gap between sessions stretches a little past their normal, then a little more. A runner whose easy pace has been drifting slower at the same heart rate for a fortnight. A swimmer three hard sessions into a decline with no recovery between them, who says they feel fine. None of these announce themselves. Each of them is visible in the sessions the week it starts, and each of them is easy to miss when the sessions are being read by someone who also has to write twenty messages before Monday.

The cost of the miss lands weeks later, as an injury, a lost month, or an athlete who drifts off without anyone having asked why. We have written about the last of those separately: what the data shows before an athlete goes quiet.

What should your assistant be able to do here?

Screening is work an assistant can do, if it has the right tools. Today you can ask yours who needs attention this week, who has gone quiet, and what changed for any athlete against their own history.

If there is a screening question you ask yourself every week that your assistant cannot answer yet, email coaching@getsimma.com and tell us the question. We build tools from those.

Simma does the screening: it reads every session your squad records, compares each one with that athlete's own recent history, and gives you a per-sport status and a reason for every athlete each week, in the web app or inside the assistant you already use. It does not have the conversations. Create your coaching account.