Why more working hours don’t always translate into better performance.
The Illusion of More
A CEO has an important strategic decision to make.
The day has already been demanding. Meetings, operational issues and urgent emails have consumed most of the available time.
At 8 p.m., the CEO decides to work another four hours.
More time to review the numbers. More time to evaluate the risks. More time to prepare.
Surely, those additional hours must translate into better results.
But what if the extra hours come at the expense of the very capacity needed to make good decisions?
This is the extra hour trap.
When More Hours Produce Diminishing Returns
There is nothing inherently wrong with working long hours.
During a major transaction, business crisis or critical project, additional effort may be necessary—and genuinely productive.
The problem begins when working longer becomes the default response to increasing demands.
Research suggests that the relationship between working hours and productivity is not always linear.
Economist John Pencavel examined historical data from British munitions workers and found that beyond a certain point, additional working hours generated progressively smaller increases in output.
The study involved industrial workers rather than modern executives, so its findings should not be treated as a precise productivity formula for CEOs.
Nevertheless, it challenges a deeply ingrained assumption:
Twice the working hours do not necessarily produce twice the results.
And for leaders whose work depends heavily on judgment, problem-solving and decision-making, the implications deserve serious consideration.
The Hidden Cost of Borrowing from Sleep
Consider an executive who regularly extends the working day by sacrificing two hours of sleep.
Initially, the arrangement may seem manageable.
The executive remains productive, meetings continue and deadlines are met.
But the consequences of repeated sleep restriction may accumulate.
In a controlled study, Van Dongen and colleagues (2003) restricted healthy adults to four, six or eight hours in bed per night over 14 consecutive days.
Participants in the four- and six-hour conditions demonstrated progressively worsening cognitive performance.
Perhaps most concerning, their subjective assessment of sleepiness did not fully reflect the extent of their increasing impairment.
In other words, people may become accustomed to feeling tired without becoming equally resistant to the performance consequences of insufficient sleep.
For business leaders, this creates a potentially dangerous blind spot.
The executive may still feel confident.
The experience and expertise remain.
But the capacity to sustain attention and process information effectively may be compromised.
The additional working hours may have created more time to work—while reducing the quality of the capacity available to perform that work.
Capability Is Not the Same as Capacity
Organisations invest heavily in leadership capability.
They develop strategic thinking, financial expertise, negotiation skills and decision-making competencies.
These investments matter.
But capability alone does not guarantee consistent performance.
To illustrate this relationship, I propose a simple conceptual framework:
Effective Leadership Performance ≈ Capability × Available Capacity
Capability represents what a leader knows and can do.
Capacity represents the cognitive, emotional and biological resources available to apply those capabilities effectively.
This is a conceptual framework rather than a scientifically validated mathematical equation.
Its message is straightforward.
A leader may possess exceptional capabilities but struggle to apply them consistently when chronically fatigued.
Working longer increases the time available for performance. It does not necessarily increase the capacity to perform well.
This distinction is particularly important when decisions involve substantial financial commitments, strategic uncertainty or significant consequences for employees and stakeholders.
The Difference Between a Sprint and a Marathon
Elite athletes understand that extraordinary effort cannot be sustained indefinitely without adequate recovery.
A sprinter may push to the limit during a race, but does not attempt to maintain that intensity throughout every hour of training.
Similarly, executives sometimes need to operate at exceptional intensity.
A merger, financial restructuring or operational emergency may demand long hours and difficult trade-offs.
But an occasional sprint is different from an organisation that operates in permanent crisis mode.
Short-term intensity may be necessary. Chronic exhaustion should not become a leadership strategy.
The objective is not to eliminate demanding work.
It is to manage demanding work in ways that preserve the capacity required for sustained effectiveness.
Three Questions Every Leader Should Ask
Before extending another working day, consider three questions.
1. Am I creating meaningful value—or simply staying busy?
Additional hours should be evaluated by the quality of outcomes, not merely the volume of activity.
2. What is the opportunity cost of this extra hour?
If another hour of work consistently reduces sleep, the trade-off may affect attention, judgment and effectiveness the following day.
3. Is this an exceptional demand—or has it become my normal operating model?
Occasional periods of intense effort are different from chronic overwork. The latter deserves closer attention because its effects can accumulate.
These questions are not arguments for working less regardless of circumstances.
They are arguments for working more intelligently.
The Real Measure of Leadership Performance
For many executives, time is the most visible measure of commitment.
We can count hours worked, meetings attended and emails answered.
But the quality of leadership performance is harder to measure.
It is reflected in the decisions made, problems solved, risks identified and people led.
More hours can sometimes help achieve these outcomes.
But beyond a certain point, additional effort may offer diminishing returns—particularly when it repeatedly displaces recovery.
The challenge for leaders is therefore not simply to find more hours in the day.
It is to ensure that the hours available are supported by the capacity to use them effectively.
The objective of leadership is not to maximise working hours. It is to maximise the quality of performance those hours produce.
Perhaps the next time we consider working late, we should ask ourselves:
Will this extra hour genuinely improve tomorrow’s outcome—or am I borrowing from tomorrow’s performance to complete today’s work?
References
- Pencavel, J. (2015). The productivity of working hours. The Economic Journal, 125(589), 2052–2076. https://doi.org/10.1111/ecoj.12166
- Van Dongen, H. P. A., Maislin, G., Mullington, J. M., & Dinges, D. F. (2003). The cumulative cost of additional wakefulness: Dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation. Sleep, 26(2), 117–126. https://doi.org/10.1093/sleep/26.2.117