This is one of the more dangerous assumptions I have made as a leader and it is a very understandable one: if someone continues to perform well, they must be coping well.

For many years, I worked in demanding operational environments where pressure was simply part of the job. There were deadlines, disruptions, customers, reorganisations, systems problems and targets that did not disappear because people were having a difficult week. You learned to deal with it.

And the people you relied on most were usually the people who dealt with it best.

They stepped in when something went wrong. They took another project because you knew they would deliver. They helped colleagues who were struggling. When an important customer issue appeared, their name came up. When a vacancy remained open, they covered the gap.

I have done exactly this with good people. And others have done it with me. The problem is that high performers can be remarkably good at hiding declining capacity.

I know this from both sides of the table. As a leader, I have continued giving work to people because I trusted them to deliver. And as a high performer myself, I continued delivering while my own capacity was gradually disappearing. Eventually, I ran into burnout.

Looking back, the warning signs were there. But because I was still performing, both I and the people around me could easily believe that I was still coping.

They do not necessarily need less responsibility or more protection. But they do need leaders who can recognise the difference between high performance and sustainable capacity. Increasingly, this is also a conversation I have in my coaching, particularly with leaders in demanding operational environments.

Look beyond the output

When someone is struggling visibly, leaders usually notice. Performance deteriorates. Deadlines are missed. Behaviour changes. Someone asks for help. You step in as a leader.

The greater risk may be the person whose performance doesn’t deteriorate, and where you do not step in. Simply because they know how to compensate.

They work longer. They prepare at night. They shorten recovery time. They become more selective about where they spend their energy. They quietly stop doing things that are not immediately necessary.

And the dashboard stays green. But underneath it, something is changing.

This is why I now distinguish much more explicitly between performance and capacity.

The signals are often small

As a leader, I would not start by asking, “Are you overloaded?” High performers are quite likely to say no and they may genuinely believe it, as they have built much of their professional identity around being able to cope.

Instead, become curious about changes. High performers rarely move from coping well to being overloaded overnight. The shift is usually gradual and visible first in small changes in behaviour, energy and interaction with others. The important question is therefore not “Is this person still performing?” but “What is different from three or six months ago?” Look for changes from their normal pattern rather than comparing them with other people. A highly capable leader under considerable strain may still outperform most of their colleagues. The relevant benchmark is often the person against themselves.

Someone who normally contributes broadly becomes very transactional. A leader who used to have time for colleagues starts protecting every gap in the diary. Irritation appears more quickly. Strategic thinking gives way to getting through the immediate workload. Delegation decreases because explaining something to somebody else feels like more work than doing it yourself.

None of these signals proves overload. Together, however, they should make you curious.

There is another signal I have learned to watch particularly carefully: the reliable person keeps getting more work precisely because they remain reliable.

That can become a dangerous reinforcing loop.

Ask a different question

Rather than asking whether someone can take another assignment, I prefer questions that make it easier to talk about both workload and the person behind the workload:

This last question really matters, because adding a priority without removing one is not prioritisation. It is accumulation. How often do you accumulate because you want things done properly and reliably?

But I would also go beyond work. How are you, really? Are you still enjoying what you are doing? When was the last time you properly switched off? What happens to your energy when you get home? Are you sleeping well? What are you giving up outside work to keep this going? And perhaps most importantly: if nothing changes for the next six months, would that be okay?

These questions are not for a checklist, and certainly not questions to fire at someone in one conversation. They require trust and genuine interest. Sometimes one question, followed by enough silence to allow a real answer, tells you more than any workload dashboard.

And the consequences of missing the signals can be substantial. When a high performer finally reaches the point where they can no longer work, you do not simply lose one person’s capacity. You often lose someone who carries critical knowledge, relationships, informal leadership and some of the organisation’s most difficult work. Their responsibilities then move to colleagues who may already be stretched, creating exactly the conditions that caused the problem in the first place. What looked like an individual capacity issue can quickly become a team performance and business continuity issue.

There is one question I have learned to value particularly:

For a high performer, that can open a very different conversation.

If you are a leader: look beyond the people who are visibly struggling. Look carefully at the people who never complain, who always volunteer and whose numbers remain excellent!

Your strongest performers may not show you that they are overloaded until the price of overload has already become significant.