Contents
Interval Workout Generator
Build an interval session timeline using your planned pace. See exact work, recovery and preparation totals within a selected time budget.
Build a session timeline
Use a work pace and session type already chosen with your training plan or coach. This tool fits illustrative repetition templates into a time cap; it does not determine your fitness, prescribe an appropriate intensity, or use Strava data. For race-specific work, enter the intended pace for that race. The tool uses exactly that pace, without a hidden race-time multiplier.
The size options select template dimensions, not beginner/advanced suitability. A session fitting your calendar does not establish that it fits your training. If your plan specifies different preparation, recovery or repetitions, follow that plan rather than treating this template as an equivalent replacement.
What the schedule includes
Every output reserves 15 minutes for an easy warm-up, 5 minutes for preparation, and 10 minutes for an easy cool-down. The preparation allowance includes any drills or strides and their recovery already called for by your plan; it is not a requirement to add them. These are disclosed scheduling assumptions, not clinically validated minimums. Allow more time if your planned preparation needs it.
Recovery appears between repetitions only. After the final repetition, the timeline moves directly into the cool-down. The output does not add a separate final recovery.
| Template | Small / medium / larger work repetition | Between-repetition recovery | Maximum repetitions |
|---|---|---|---|
| Longer distance | 400 / 800 / 1,000 metres | 2:00 | 4 / 6 / 8 |
| Short distance | 200 metres for all sizes | 1:30 | 6 / 8 / 10 |
| Timed, 40-minute cap | 3:00 / 4:00 / 4:00 | 1:30 small; 2:00 others | 4 / 5 / 6 |
| Timed, 60- or 75-minute cap | 5:00 / 8:00 / 8:00 | 1:30 small; 2:00 others | 4 / 5 / 6 |
| Race-specific, 5K or 10K | 1,000 metres for all sizes | 1:30 | 4 / 6 / 8 |
| Race-specific, half marathon or marathon | 1 mile for all sizes | 1:30 | 4 / 6 / 8 |
These presets are editorial examples for scheduling, not recommendations established by a training study. No qualified coaching review is claimed. The calculator reduces the repetition count to fit the selected cap. It requires at least two repetitions; if two do not fit, it returns an explanation instead of removing preparation. An unused portion of the budget is not an instruction to add more work.
The arithmetic
One mile is exactly 1,609.344 metres. For distance repetitions:
work seconds = round upward(distance metres ÷ 1,609.344 × supplied seconds per mile)
Each distance repetition is rounded upward to a whole second so the displayed schedule does not underestimate its calculated duration. Timed repetitions use their stated duration directly; your supplied pace does not change their length.
session seconds = 1,800 + repetitions × work seconds + (repetitions − 1) × recovery seconds
The largest count that fits this formula is capped by the template maximum. All displayed work, recovery and session totals come from the same ordered schedule. Paces must be in minutes:seconds format, with seconds from 00 to 59. The supported 2:00–30:00 per mile range is a tool input boundary, not a suitability judgment.
Worked example: a 40-minute session
Select medium, sustained timed repetitions, up to 40 minutes, and a planned pace of 8:00 per mile. Race distance is unused for this template.
| Elapsed time | Step | Duration |
|---|---|---|
| 0:00–15:00 | Easy warm-up allowance | 15:00 |
| 15:00–20:00 | Preparation allowance | 5:00 |
| 20:00–24:00 | Work repetition 1 | 4:00 |
| 24:00–26:00 | Recovery | 2:00 |
| 26:00–30:00 | Work repetition 2 | 4:00 |
| 30:00–40:00 | Easy cool-down allowance | 10:00 |
The result is 2 × 4:00, exactly 8:00 of work, 2:00 between-repetition recovery, and 40:00 overall. A third repetition would require 46:00, so it is omitted. The 8:00 pace is supplied by the runner; this example does not recommend that pace to other runners.
For a distance check, a 1-mile repetition at 8:00 per mile lasts exactly 8:00. Two such repetitions with 1:30 recovery and the 30-minute allowances total 47:30; they cannot fit the 40-minute cap.
Preparation, progression and weekly placement
Use the warm-up and preparation your existing plan calls for, and check that their actual duration fits the reserved time. Do not shorten needed preparation to squeeze in another repetition. Your recovery style—walking, jogging or standing—also comes from the intended session; the timeline records time, not a recovery prescription.
Treat changes in repetition count, repetition length, recovery and pace as changes to the session, not interchangeable ways to fill spare minutes. Compare a proposed change with your plan or discuss it with your coach before progressing. Selecting “larger” is not evidence that progression is appropriate.
Place the session in the quality-work slot of your existing week. Check adjacent hard sessions and long runs before moving it, and reassess the week as a whole if the schedule changes. This generator cannot see your other training, recovery or symptoms and therefore does not assign a weekday or a weekly interval frequency.
Copy your session and review it
Use Copy summary and guide to save the calculated timeline and this worksheet, or Print / Save PDF to print the result. Calculate first so the export includes your session.
| Planning question | Your note |
|---|---|
| Where did my work pace and session choice come from? | |
| What is the intended place in my existing training week? | |
| Do the preparation and recovery allowances match my plan? | |
| What would make me change or stop this session? | |
| Afterward: what did I actually complete, and how did it compare? |
For converting a pace you already have between units, use the pace calculator. Keep the distinction between calculating a schedule and selecting appropriate training.