What is a good work-to-rest ratio?

For VO2max intervals: 1:1 (e.g. 4 min on, 4 min off). For anaerobic: 1:2 or 1:3. For sweet spot: 2:1 or continuous. It depends on the training target.

How many intervals should I do?

Start with 3-4 intervals and build up. For 4-minute VO2max intervals, 5-6 is a good target. For shorter 30-second anaerobic efforts, 8-12 is common.

Should I include warm-up and cool-down?

Always. A proper warm-up of 10-15 minutes prepares your body and improves interval quality. A cool-down of 5-10 minutes aids recovery.

bikecalcs.uk

Interval Calculator — Plan Interval Sessions

Plan cycling interval training sessions with work and rest periods.

Number of Intervals

How many work efforts in the session, e.g. 4–6 for 4-min VO2max efforts or 8–12 for 30-second anaerobic efforts

Warm-up

Easy spinning to prepare for hard efforts, typically 10–15 min

Work Minutes

Time in minutes

Work Seconds

Time in seconds

Rest Minutes

Time in minutes

Rest Seconds

Time in seconds

Cool-down

Easy spinning to aid recovery after the efforts, typically 5–10 min

How We Calculate This

Interval Session Structure

The calculator sums warm-up, work intervals, rest periods between intervals, and cool-down to give total session time.

Total = Warm-up + (Work x Intervals) + (Rest x (Intervals - 1)) + Cool-down

Note: rest periods are between intervals, so there is one fewer rest period than work periods.

Frequently Asked Questions

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Last updated: June 2026

All calculations are estimates. Always verify results and consult a professional bike fitter where appropriate.