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Work{{ displayReady ? `${displayInputs.work_sec}s` : '—' }} Recovery{{ displayReady ? `${displayInputs.rest_sec}s` : '—' }} Work density{{ displayReady ? formatPercent(displayComputation.values.work_density_percent) : '—' }}
{{ stagePhaseLabel }}{{ stageTimeDisplay }}{{ stageStepLabel }}
Selecting a preset replaces the editable timing and exercise fields.
Use 1 to 12 lines, up to 40 characters each.
Whole seconds from 5 to 180.
s
Use 0 for continuous work, or up to 180 seconds.
s
Whole rounds from 1 to 40.
rounds
Whole sets from 1 to 10.
sets
From 0 to 600 seconds in five-second steps.
s
Use 0 to start immediately, or up to 120 seconds.
s
Audio starts only after you press Start.
{{ volume_pct }}%.
Off by default; unsupported browsers ignore vibration requests.
{{ vibrate ? 'On' : 'Off' }}
Off by default; the browser or operating system may revoke a requested wake lock.
{{ keep_awake ? 'On' : 'Off' }}

{{ chartExportStatus }}

The chart renderer is unavailable. The same durations remain available in the plan and interval ledger.

#PhaseSet / roundExerciseStartsDurationCopy
{{ row.sequence }}{{ row.phase }}{{ row.setRound }}{{ row.exercise }}{{ row.starts }}{{ row.duration }}

{{ tableExportStatus.interval_ledger }}

TimeCuePhaseExercisePurposeCopy
{{ row.time }}{{ row.cue }}{{ row.phase }}{{ row.exercise }}{{ row.purpose }}

{{ tableExportStatus.cue_sheet }}

TimeEventIntervalStateCopy
{{ row.time }}{{ row.event }}{{ row.interval }}{{ row.state }}
Start the timer to record local run events.

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HIIT Workout Timer Plan and run a HIIT workout with named exercises plus warm-up and cooldown phases, work-density checks, and clear live interval cues.
EMOM Workout Timer Build an EMOM minute plan with repeatable movement targets, estimated rest buffers, pacing warnings, and a live workout timer.
AMRAP Workout Timer Build and run an AMRAP workout timer with round-split planning, pace warnings and live partial-score logging that stays in your browser.
Rate of Perceived Exertion (RPE) Calculator Convert Borg, CR10 or lifting RPE into relative effort with scale equivalents, sRPE load bands and optional heart-rate estimates.

“Tabata” is often used for any workout that alternates 20 seconds of activity with 10 seconds of recovery. The original research was narrower: seven to eight 20-second bouts at extremely high intensity on a cycle ergometer, separated by 10 seconds of rest. Reproducing the clock pattern does not reproduce the same workload, training population, or laboratory conditions.

That distinction makes Tabata-style a useful name for bodyweight, strength, low-impact, and mixed-movement sessions that borrow the short interval structure. Exercise choice determines whether ten seconds is enough to recover and reposition. A stationary cycling effort needs little transition, while a floor-to-standing sequence or equipment change can consume most of the rest period.

StructureTimingHow to describe it
Original research protocol20 seconds work, 10 seconds rest, 7 to 8 boutsA specific exhaustive cycling protocol studied in a small trained sample.
Classic timer block20 seconds work, 10 seconds recovery, 8 roundsA four-minute interval block using the familiar timing pattern.
Custom or multi-set planEditable work, recovery, rounds, sets, and set breaksTabata-style interval training rather than the original protocol.

Short recovery creates the defining constraint. It can preserve rhythm for a simple movement, but it may be too brief for changing loads, checking technique, or making a safe transition. Adding a longer break between sets changes total density without altering the repeated work/recovery pair inside each set.

A list of exercises rotates across work rounds and repeats when the number of rounds exceeds the list length. Fewer, clearer movements can be easier to perform consistently than a different exercise every round. Complex or unfamiliar exercises are poor choices when fatigue and rapid cues leave little time to correct position.

The timer supplies structure, not proof of intensity or medical readiness. Start below maximal effort when the format is unfamiliar, use movements that remain stable under fatigue, and stop for chest pain, dizziness, faintness, unusual shortness of breath, or sharp pain.

How to Use This Tool:

Choose between a classic timing block and an adapted interval plan, then verify that the exercise changes fit inside the recovery periods.

  1. Select a Timer preset or edit the timing fields. Presets replace the exercise rotation and primary timing values, so review the whole plan after changing one.
  2. Enter 1 to 12 exercise names, one per line. Keep names short enough to recognize during a three-second warning and place awkward equipment changes between sets rather than inside a ten-second round recovery.
  3. Set work, round recovery, rounds per set, number of sets, between-set recovery, and preparation countdown. A round recovery of 0 creates continuous work phases.
  4. Review Set mix and Interval ledger. Confirm complete timer length, work density, and the ordered exercise rotation before starting.
  5. Choose beep, voice, or silent cues and test the device. Press Start to freeze the current plan; edits during a run take effect only after a fresh start.

Interpreting Results:

Work density is the percentage of complete timer time assigned to work. Preparation, recovery after every round, and breaks between sets all lower it. The value describes the schedule only; it does not measure power, heart rate, oxygen uptake, repetitions, or exercise quality.

The interval ledger is the authoritative phase order for the frozen run. Exercise names repeat by position in the rotation, so eight rounds with four exercise names produces two passes through those four names. Check the ledger when the desired exercise order is more important than the preset label.

A classic 20/10 × 8 plan reproduces the familiar timing pattern. Custom work periods, multiple sets, or different recovery values should be interpreted as adapted Tabata-style intervals rather than evidence that the original research protocol was performed.

Technical Details:

The ordered session begins with optional preparation. Each set then contains the same number of work rounds, and every work round is followed by its configured round recovery, including the final round of the final set. A between-set break is added only after non-final sets.

Formula Core

Let S be the number of sets, R rounds per set, w work seconds, r round-recovery seconds, b between-set recovery, and p preparation.

W=S⁢R⁢wQ=S⁢R⁢rB=(S−1)b

Complete timer time includes all four components, and density uses that complete total.

T=p+W+Q+BD=WT×100

The Classic 20/10 × 8 preset has 160 work seconds and 80 recovery seconds, making the interval block exactly 240 seconds. Its 10-second preparation produces a complete timer of 250 seconds and a displayed density of 64%. The 60-second set-break value is unused because a one-set plan has no between-set boundary.

Transformation Core

Exercise assignment cycles by round position within every set. If the rotation contains e names, round j uses the name at position (j - 1) modulo e. Each nonzero work or recovery segment receives a start and end time; zero-second recovery segments are omitted. Work and recovery segments lasting at least eight seconds also receive a three-second warning cue.

Work accepts 5 to 180 whole seconds, round recovery 0 to 180, rounds 1 to 40, sets 1 to 10, between-set recovery 0 to 600, and preparation 0 to 120. Exercise names are limited to 40 characters. Percentages are calculated from integer seconds and rounded only for display.

Cue style, cue volume, vibration, and screen-wake settings affect the live experience but not the interval ledger or arithmetic. The run event log records timer actions and phase changes, not exercise completion or physiological response.

Safety Notes:

  • Choose movements that need little setup and remain controllable near the end of a set.
  • Reduce pace, resistance, work duration, or round count when ten-second recovery no longer restores safe movement.
  • Allow a gradual warm-up and cooldown outside the timer when the selected plan does not include them.
  • Treat sound, speech, vibration, and screen-wake support as optional; keep the visible countdown available.

References: