Defining productivity may seem straightforward. Yet as soon as we leave the production line behind and start talking about intellectual work, the word becomes much less clear. Are we productive because we complete many tasks? Because we work quickly? Because we fill our days?
Taking two minutes to clarify what we are actually trying to improve changes how we look at every method discussed on this blog. In my view, personal productivity is not about producing as much as possible at every moment. It is mainly about making the best use of the energy available to us.
The economic definition of productivity
In economics and management, productivity measures the efficiency of a production process. It is the relationship between an output—the goods or services produced—and the resources used to achieve it, such as labor or capital.
This definition is very concrete. If a factory makes more parts with the same number of machines and the same number of working hours, its productivity increases. Both output and resources can be counted, compared, and tracked over time.
The difficulty appears when we apply this logic to what is usually called personal productivity. Blogs, books, and tools devoted to the subject rarely discuss producing identical objects on an assembly line. Instead, they deal with writing, thinking, making decisions, organizing projects, solving problems, or coordinating people.
These intellectual tasks are far less tangible. Two hours of thinking may produce no immediately visible result, then unlock an entire project. Conversely, a day filled with small actions can produce a long list of checked boxes without moving anything important forward.
Why counting tasks is not enough
We could try to reproduce the economic measure by counting the number of tasks started or completed. This kind of tracking is not absurd. In some situations, it helps show whether a system is moving forward, whether work in progress is accumulating, or whether we are misjudging how much we can accomplish.
The problem would be treating this as a complete definition of productivity. Not all tasks have the same cost or value. Replying to three messages, booking an appointment, and filing a document produces four completed tasks. Preparing a difficult decision or writing the first draft of a report may produce only one, despite requiring much more attention and having a much greater impact.
Measurement can also encourage the wrong behavior. If my goal becomes completing as many tasks as possible, I have an incentive to choose the shortest ones, divide my work artificially, and avoid complex subjects. The number rises, but what matters does not necessarily move forward.
We therefore need to be able to track activity without confusing that tracking with the outcome we want. A completed task remains useful information; it is not a universal unit of productivity.
Productivity as energy management
For intellectual work, my definition is simpler and more broadly applicable: being productive means making the best possible use, at any given moment, of the energy available to you.
This energy covers several things that we sometimes distinguish from one another: concentration, motivation, the capacity to make decisions, or simply the willingness to tackle a subject. The fuel metaphor is imperfect, but useful. We wake up in the morning with a certain amount of energy. It generally declines throughout the day, even though the exact level fluctuates depending on the person, the activity, and what happens around us.
This definition changes the question we should ask. Instead of constantly trying to do more, we try to make the best possible use of our current state. That does not mean waiting until we feel perfectly motivated before working. It means recognizing that an hour of deep concentration and half an hour of fatigue do not allow us to achieve the same things, then organizing our work accordingly.
Nor is energy an excuse for postponing difficult tasks indefinitely. A good system should help reserve the best conditions for demanding subjects and use less favorable moments for simpler actions.
Working at the scale of a single day
At the scale of a day, managing your energy first means matching the task to the moment. When I have peace and quiet and can concentrate well, it would be a waste to spend that period sorting notifications. I prefer to reserve it for work that requires thought, creativity, or decision-making.
When my energy drops, I can instead handle more mechanical actions: filing documents, replying to a few simple messages, preparing for an appointment, or completing an administrative task. These things still need to be done, but they do not necessarily require my best hours.
Alternation matters as well. Completing several highly demanding tasks in a row can quickly exhaust your attention. Moving on to a lighter action lets you keep making progress without pretending that you can maintain the same level of concentration all day. The right choice depends on the priority, the available time, the context, and your energy at that moment.
Some “hacks” are designed to create a small artificial boost: drinking coffee, changing your environment, starting a timer, or using a motivational technique. They can help you begin or finish a task. Used in moderation, they can temporarily mobilize energy that felt hard to access.
They are not a substitute for a sustainable system, however. Continually relying on stimulants and tricks to compensate for fatigue is like pressing the accelerator when the fuel tank is nearly empty. It may work for a while, but it does not solve the underlying problem.
Increasing your energy over the long term
The same logic also works on a larger scale. The goal is no longer simply to distribute one day’s energy intelligently, but to maintain and, where possible, increase your overall capacity to act.
Health habits obviously play a role: sleeping properly, moving, eating in a way that works for us, and allowing time for genuine recovery. The aim is not to turn every aspect of life into an optimization program. It is simply difficult to build a reliable productivity system if that system depends on a level of energy your daily life never allows you to reach.
Motivating activities matter too. A meaningful project, a task with a visible result, or a pleasant working environment can make effort much easier. To return to the fuel metaphor, these choices sometimes increase the size of the tank and sometimes improve the vehicle’s fuel efficiency.
The state of flow illustrates this phenomenon well. When we are fully absorbed in an activity suited to our abilities, effort feels more fluid and our energy almost unlimited. We cannot summon this state on command, but we can make it more likely by protecting time, reducing interruptions, and choosing a sufficiently stimulating challenge.
We should not make flow a prerequisite for working, however. Most days contain unexciting obligations and periods of fatigue. Productivity is not about remaining in flow at all times, but about creating favorable conditions when possible and staying capable of moving forward when those conditions are absent.
A system designed to conserve energy
The entire system I present on this blog follows this definition. Its different components are not merely filing tools. Each one prevents us from spending attention on a question that should already have an answer.
A well-managed calendar prevents us from wasting energy remembering that an event must take place at a particular time. We can trust the calendar to represent time constraints instead of constantly holding them in our heads.
Well-organized inboxes reduce the need to keep checking messages, notifications, and other incoming signals. Information is captured in a known place, then processed at the appropriate time. As with the calendar, a reliable system frees up attention.
Finally, the Kanban, which forms the heart of the system, shows which tasks are genuinely actionable and lets us choose among them. Priorities remain essential, but they are not the only criterion. Between two useful tasks, I can choose the one that best fits the time, context, and energy available to me.
This organization also reduces decision fatigue. If every work session begins with a search through messages, notes, and open tabs, some of the available energy disappears before we have even decided what to do. A well-maintained system prepares that decision in advance.
Doing better with the energy available
Productivity cannot therefore be reduced to either the number of hours worked or the number of tasks checked off. Those figures may be interesting, but they do not tell us whether we devoted our best resources to what truly mattered.
Thinking in terms of energy provides a more useful guide. In the short term, it means choosing a task that fits your current state and protecting periods of concentration. In the long term, it means maintaining your capacity to act and building an environment that wastes as little attention as possible.
A good productivity system does not try to turn every minute into measurable output. Above all, it should make good choices easier, help us move important subjects forward, and preserve enough energy for the whole arrangement to remain sustainable over time.