Two people can carry identical workloads and experience entirely different levels of strain. The variable that separates them most reliably is how much say they have over how the work is done.
Demand and discretion are separate dimensions
Occupational research has long treated the amount asked of a person and the latitude they have in responding as two independent axes rather than one.
High demand paired with high discretion tends to be experienced as challenge. The same demand with low discretion tends to be experienced as pressure that cannot be relieved.
This is why demanding jobs are not uniformly harmful, and why some low-demand jobs are unexpectedly draining.
Predictability does much of the work
Control matters partly because it makes what happens next predictable. A person who can influence timing knows roughly when the demand will arrive and can prepare.
Without that, the body has to stay in a state of readiness because the demand could come at any moment. Readiness maintained continuously is more costly than readiness deployed and released.
Interruption-driven work is taxing for this reason rather than because any single interruption is difficult.
The stress response is designed to end
The physiological response to a demand is a mobilisation: energy released, attention narrowed, systems that can wait deprioritised. It is efficient and intended to be brief.
Recovery is the other half of the design. When the demand passes, the systems that were deprioritised resume and the mobilisation is paid back.
Low control interferes with that second half more than the first. The demand never clearly ends, so the return never clearly begins.
Small discretion has outsized effects
The latitude that matters is often minor: choosing the order of tasks, deciding when to take a break, having some influence over a deadline rather than none.
These do not reduce the workload at all. They change whether the person is responding to the work or only absorbing it.
This is also why removing small autonomies from an otherwise unchanged job is felt so sharply by the people doing it.
What this implies for managing pressure
Advice aimed only at the individual — breathe, sleep, reframe — addresses the recovery side while leaving the structural side untouched. That helps, but it is working against a continuing input.
Where any discretion can be recovered, that tends to change the experience more than an equivalent effort spent on coping technique.
Where none can be, naming the situation accurately is still worth something. Strain arising from a genuine lack of control is not a personal deficiency in handling it.