Contents
Timer, rounds, effort
An interval workout is a fixed pattern of hard work and timed rest, repeated until the session ends. This guide walks through the procedure with exact seconds, shows which work-to-rest ratio fits your level, and gives you a 6-20 scale to judge how hard each interval should feel.
Set the timer, warm up, then repeat the work-rest block until the rounds are done.
Start with a warm-up of 5 to 10 minutes at Borg 9-11. This raises heart rate and prepares muscles before the first hard interval.
Then start the timer for the work block. Work at the effort your ratio calls for, stop exactly when the timer signals, and rest for the programmed seconds. Repeat until all rounds are finished.
Cool down after the last round with easy movement until breathing settles. Total session time, including warm-up, is what the table below reports.
The ratio runs from 1:1 for trained athletes down to 1:3 for beginners.
High-intensity interval training alternates short hard efforts with recovery. Common work-to-rest ratios run from 1:1 for trained athletes to 1:3 for beginners.
A standard beginner session is 30 seconds of work and 90 seconds of rest repeated six to eight times, about 10-15 minutes including a warm-up.
The advanced end of the range is the Tabata pattern itself: 20 seconds of work and 10 seconds of rest, which is a 2:1 work-to-rest ratio and totals four minutes of intervals.
Hard intervals should feel like 15 to 17 on a scale that runs from 6 to 20.
The Borg rating of perceived exertion scale runs from 6 to 20, where 6 means no exertion and 20 means maximal effort. Hard intervals typically sit at 15-17.
Gunnar Borg published the perceived-exertion scale in Sweden. Multiplying the rating by ten approximates heart rate in beats per minute for many adults, so a 16 roughly corresponds to about 160 beats per minute.
Check the number mentally at the end of each work block. If the round reads above 17, shorten the next work block or lengthen the rest.
Hard intervals typically sit at 15-17 on a scale where 20 is maximal effort — hold that band from round one, not just at the end.
| Level | Work seconds | Rest seconds | Rounds | Session minutes (with warm-up) |
|---|---|---|---|---|
| Beginner | 30 s | 90 s | 6-8 | 10-15 |
| Intermediate | 40 s | 80 s | 6-8 | 12-16 |
| Advanced (Tabata) | 20 s | 10 s | 8 | ~8-10 |
| Warm-up (all levels) | — | — | — | 5-10 |
| Target effort (hard rounds) | Borg 15-17 | — | — | — |
| Hard sessions per week | 2-3 | — | — | — |
Most blown sessions come from starting too hard, resting too short, or stacking hard days.
Starting the first round at Borg 19-20 burns the session in the first minute. Hold the target band from round one.
Cutting rest below the programmed seconds keeps heart rate elevated and turns the next work block into a slog. Rest the full interval.
Scheduling three or more hard days in a row leaves no recovery. Interval sessions are usually limited to two or three per week so that recovery days separate the hard days.
Run down this list before and after every interval session.
The checklist below covers the timer setup, the effort target, and the weekly schedule so nothing is left to improvisation on the day.
Izumi Tabata et al., 1996; Gunnar Borg, perceived exertion scale.