Sep 19, 2026 · 6 min read
A focus sprint is a block of time with three properties: one task, a fixed end, and no reopening the decision while it runs. The length matters less than people think, and the fixed end matters more. This guide is about choosing a length you will actually keep, and then keeping it.
Deep work is Cal Newport's term for concentrated effort on something that is hard and worth doing, as opposed to the shallow kind of work that fills a day without moving anything. The distinction is useful because the two kinds fail differently. Shallow work fails by piling up. Deep work fails by never starting, because it needs a stretch of unbroken attention and an ordinary day does not offer one unless you cut it out on purpose.
A timer is how you cut it out. The moment you start a countdown you have made two decisions that would otherwise be renegotiated every few minutes: what you are doing, and for how long. Everything that arrives during the block has an answer already, which is "after the chime."
The two lengths people argue about have different origins, and neither is a law.
Twenty-five minutes is the Pomodoro Technique, developed by Francesco Cirillo in the late 1980s: 25 minutes of work, a 5 minute break, and a longer break after four rounds. The number was a practical choice that turned out to travel well. It is short enough to start without dread, and the pomodoro timer runs the whole cycle for you, breaks included.
Ninety minutes comes from a different place. The idea that alertness rises and falls in cycles of roughly that length during the day is widely cited, usually traced to Nathaniel Kleitman's work on rest and activity cycles in sleep and the suggestion that a similar rhythm continues while awake. How firmly that applies to any one person's afternoon is less settled than the popular version suggests. The honest way to use it is as a hypothesis about yourself: try a 90 minute block, and notice whether your attention actually lasts that long or fades at 50.
The better source is your own history, and radialtimers.com keeps one. On the homepage, the Leaderboard opens your record: your total time with a timer running, a chart of the last 30 days, and your current day streak. Signed in, that record follows you across devices; signed out, it lives in the browser you are using.
What to look for is not the total but the shape. If your 30 days show clusters of short runs, you are starting a lot and stopping early, and a shorter block with a real break will serve you better than a longer one you abandon. If the runs are long and the days are sparse, the length is fine and the problem is frequency. Choose the sprint length that your record says you finish, then lengthen it from there.
The stats page is a different thing: it shows the whole community, how much time everyone has kept, an hour-by-hour picture of the last 30 days, and the totals per day. It will not tell you your own number, but it does show when other people are keeping time, which some find useful company for a morning block.
A sprint holds one task. Not one project, one task: the paragraph, the function, the problem set. The reason is not moral. Every switch costs a reload, and the reload is paid in the minutes when you are technically at the desk and not yet working. One task per block means one reload per block.
A radial dial suits this because it does not ask for attention. Twenty rings empty one by one, and a glance at the edge of the screen tells you where you are without reading digits, so checking the time does not become the switch you were avoiding. Pop the dial out picture-in-picture or leave it in a background tab; the countdown follows the clock either way and chimes at zero.
Keep a capture list beside you. When something intrudes, a thought, an errand, a message you want to send, write one line and return to the task. The list is read at the chime, and most of it turns out to be nothing.
Do not start at 90 minutes. Start below what you think you can do, so that the first week is a run of finished blocks, and lengthen only after the shorter block feels easy. One block a day is enough to begin.
| Days | Block | Rounds | What to notice |
|---|---|---|---|
| 1 to 2 | 25 min work, 5 off | 2 | Whether you finish the block without stopping the timer early. |
| 3 to 4 | 25 min work, 5 off | 3 | Which round is the hardest to start. |
| 5 to 7 | 25 min work, 5 off | 4 | Whether the fourth round is still real work or just sitting there. |
| 8 to 10 | 50 min work, 10 off | 2 | Where in the block attention dips, if it does. |
| 11 to 12 | One 1 hour block, then a real break | 1 | Whether the hour felt short or long. |
| 13 | One 90 minute block | 1 | The minute at which you first wanted to stop. |
| 14 | Review the 30-day chart | Pick the length you kept, not the one you admire. |
The last day is the point of the exercise. If the 90 minute block was two good hours of work compressed into ninety minutes, keep it. If you were done at 55, the honest answer is the 50/10 cycle, and there is nothing to apologize for. The block you finish is worth more than the block you planned.
Signed in, the site keeps the record for you. Your time with a timer running counts toward the leaderboard, which can be sorted by all-time total or by best streak, and a streak is simply consecutive days with any timer time at all. A ten minute block on a bad day keeps the streak alive, which is the right incentive: the streak rewards showing up, and the total rewards staying.
None of that is required. The dial works the same signed out, and the record in your browser still shows the last 30 days. The account is for people who want the number to follow them, or who want to see it beside someone else's.
Yes. An untimed break is where the afternoon goes. The pomodoro pages time both halves and move between them on their own; for a single block, start a 5 minute timer the moment the work chime sounds.
Take the break anyway the first few times, and note where you were. If it keeps happening, that is your record telling you the block is too short, and the ramp above is the way to lengthen it.
Yes. The countdown follows the clock, not the tab, so it stays right in the background and still chimes at zero.