Circuit Training Timer

Stations: {{ resultsReady ? computation.values.station_count : '—' }} Rounds: {{ resultsReady ? computation.normalizedInputs.rounds : '—' }} Work density: {{ resultsReady ? formatPercent(computation.values.work_density_percent) : '—' }}

{{ livePhaseLabel }}{{ liveRemainingDisplay }}

Circuit preset:

A preset replaces the roster and primary timing fields.

Station roster:

Use up to 30 named stations. Pipe fields override the defaults for that station.

Default station length:

10 to 300 seconds before per-station overrides.

sec

Default station transition:

0 to 180 seconds before per-station overrides.

sec

Rounds:

1 to 12 complete passes through the roster.

rounds

Between-round recovery:

0 to 300 seconds for water, coaching, and reset.

sec

Start countdown:

0 to 60 seconds to get into position.

sec

Session emphasis:

Choose the lens used for timing guidance.

Final cleanup transition:

Use this when cleanup time belongs inside the timed session.

{{ include_final_transition ? 'Included in the run sheet' : 'Finish after final work' }}

Phase cue sound:

Optional local cue at phase changes.

Vibration cue:

Off by default and unavailable on some devices.

Keep screen awake:

Off by default; the timer remains usable without it.

{{ row.label }}{{ row.value }}

Step	Phase	Round	Station	Focus	Start	Duration	Cue	Copy
{{ phase.step }}	{{ phase.type_label }}	{{ phase.round_label }}	{{ phase.station_name }}	{{ phase.focus_label }}	{{ formatClock(phase.start_seconds) }}	{{ formatDuration(phase.duration_seconds) }}	{{ phase.cue }}

Check	Read	Evidence	Action	Copy
{{ row.check }}	{{ row.status }}	{{ row.note }}	{{ row.action }}

Event	Clock	Phase	Detail	Copy
{{ row.event }}	{{ row.clock }}	{{ row.phase }}	{{ row.detail }}

In a busy circuit, the seconds between exercises matter almost as much as the work periods. A short move from a floor exercise to a loaded station may be enough for one person, yet leave a class queuing for equipment or starting before everyone is ready. The schedule has to account for exercise time, physical movement, coaching, water, and the reset between complete passes through the room.

A station is one named exercise or task. A round is one pass through every station, while a transition is the time used to reach and prepare for the next station. A longer round recovery creates a shared pause after the last station before the roster begins again. These pauses are not automatically wasted time. They protect setup quality and make a written circuit runnable in the space where it will actually happen.

Strength-focused circuit: Longer work periods and recovery can support controlled repetitions, load changes, and stable technique.
Conditioning circuit: Shorter transitions raise the share of active work, provided the movements and room layout remain simple.
Technique circuit: More time between efforts can be useful when instruction, positioning, or careful repetition matters more than pace.

Work density describes the percentage of work-and-recovery time spent at stations. It is useful for comparing two versions of the same circuit, but it is not a direct measure of exercise intensity. A high-density plan can still use easy movements, while a lower-density strength circuit can contain demanding loads. Exercise choice, load, ability, environment, and fatigue still decide how hard the session feels.

Station order also changes how a circuit behaves. Alternating lower-body, upper-body, pulling, pushing, core, and cardio tasks may spread local fatigue more evenly than repeating one demanding area. That balance is a planning clue rather than a universal prescription. Sport practice, rehabilitation, equipment limits, and group supervision can all justify a narrower focus.

Timing cannot judge movement quality, pain, dizziness, heat stress, or readiness for vigorous exercise. A workable plan leaves enough time to move safely and can be reduced when form or control deteriorates. Public physical-activity guidance also concerns activity accumulated over time; one timer session does not establish that a weekly target has been met.

How to Use This Tool:

Build the roster around the room and equipment first, then check the computed schedule before starting the live timer.

Choose a Circuit preset or enter one station per line in Station roster. A line can contain only a name, or use Name | focus | cue | work | transition when one station needs different timing.
Set the default station length, transition, number of rounds, and between-round recovery. Add a start countdown or final cleanup transition only when those periods belong inside the timed session.
Select the Session emphasis that best matches the plan. It changes the density check used for coaching guidance, not the timer sequence or the physical intensity of an exercise.
Review Plan snapshot, Run sheet, and Coaching checks. Correct a missing roster, an impractical transition, or a warning about duration or density before pressing Start.
Start the session after the plan is ready. The active run keeps the schedule that was current at Start; later edits belong to the next run.

Interpreting Results:

Total session includes preparation, station work, transitions, round recovery, and an optional final transition. Work density excludes the preparation countdown, so it answers a narrower question: how much of the work-and-recovery block is active station time.

The focus comparison groups planned work seconds by the focus assigned or inferred for each station. Treat it as a roster audit, not an assessment of muscular demand. Equal seconds of squats and rows do not imply equal load, effort, or training effect.

A High, Watch, or Tight coaching status comes from the declared planning rules below. It should prompt a check of room flow, supervision, and recovery; it does not diagnose overtraining or certify a session as safe.

Technical Details:

The station roster becomes an ordered phase schedule. Every station receives its work time, but its transition is used only when another station follows in the same round. The last station instead leads to the between-round recovery, except after the final round when an optional cleanup transition may be added.

Formula Core

For n stations and R rounds, total station work is the sum of each station duration repeated for every round.

W = R \sum_{i = 1}^{n} w_{i}

Recovery includes transitions between stations, round breaks between repeated passes, and the final transition only when it is enabled.

Q = R \sum_{i = 1}^{n - 1} t_{i} + (R - 1) b + F t_{n}

Here, w_i is station work in seconds, t_i is its transition, b is the between-round recovery, and F is 1 when final cleanup is included and 0 otherwise. Preparation p is added to the complete session but excluded from density.

\begin{matrix} T & = & p + W + Q \\ D & = & \frac{W}{W + Q} \times 100 \end{matrix}

Rule Core

Density guidance is a repo-authored planning rule. Values exactly on a listed boundary stay in the balanced range; only values strictly below the lower boundary or strictly above the upper boundary change status.

Work density coaching boundaries by session emphasis
Emphasis	Watch below	Balanced range	High above
Balanced circuit	48%	48% to 85%	85%
Strength stations	35%	35% to 77%	77%
Conditioning density	58%	58% to 93%	93%
Technique practice	28%	28% to 75%	75%

A session shorter than 480 seconds is marked Short. From 480 through 2,100 seconds it is Ready; above 2,100 through 3,300 seconds it is Watch; above 3,300 seconds it is Long. A separate warning appears when density is above 88% and work exceeds 600 seconds, or when the complete plan exceeds 4,500 seconds.

Default station time accepts 10 to 300 whole seconds and default transition time accepts 0 to 180. A per-line work override is rounded and bounded to 5 to 600 seconds; a per-line transition is rounded and bounded to 0 to 300. The roster uses at most the first 30 non-comment station lines.

Safety and Planning Limits:

The timing model cannot measure load, technique, balance, heart rate, room temperature, or recovery between sessions. Begin conservatively, increase activity gradually, and leave enough transition time for the actual equipment and number of participants.

Stop the session for pain, dizziness, faintness, or loss of movement control.
Do not treat a favorable density status as medical clearance or proof that every station is suitable.
Test sound, vibration, and screen-wake behavior on the device before relying on them for group cues.

References:

Physical Activity Guidelines for Americans, 2nd edition, U.S. Department of Health and Human Services, 2018.
Measuring Physical Activity Intensity, Centers for Disease Control and Prevention.