Two kinds of timing, two different jobs

Use the Tabata timer when the task is to alternate an activity with a break on a repeating schedule. A round is a block of work, not a promised number of reps. Use the Gym timer when you want a consistent lift, pause, and lowering pace across reps and sets. The two patterns measure different things; a 20-second work interval cannot by itself tell you how many controlled reps fit.

For eight rounds of 20 seconds work / 10 seconds rest, work totals 8 × 20 = 160 seconds. If rest only happens between rounds, there are seven rests: 7 × 10 = 70 seconds. The block lasts 230 seconds, or 3 minutes 50 seconds. Include the rest after round eight and the rest total becomes 80 seconds, bringing the block to 4 minutes.

That calculation does not include a preparation countdown, transitions between exercises, or a warm-up and cool-down. Decide whether the final recovery belongs to this block or the next part of your session before estimating your finish time. The Tabata timer lets you choose whether to include that last rest.

At a 2–1–3 tempo, one rep takes 2 seconds to lift, 1 second to hold, and 3 seconds to lower: 6 seconds per rep. Eight reps take 48 seconds. Three sets of eight contain 24 reps, or 144 seconds (2 minutes 24 seconds) of timed reps.

If you plan 90 seconds of rest between those three sets, there are two rests: 2 × 90 = 180 seconds. The planned total is 324 seconds (5 minutes 24 seconds), excluding setup and transitions. The Gym timer includes rest between sets and between exercises, but not after the final set of the routine. If you deliberately take another 90-second recovery afterward, your real session becomes 414 seconds (6 minutes 54 seconds); that extra recovery is outside the timer total.

Here is a timing example, not a prescribed workout: allow a separate 5-minute easy warm-up, then run six rounds of 20 seconds of a familiar activity and 20 seconds of recovery. With no final rest, that interval block is 6 × 20 + 5 × 20 = 220 seconds (3 minutes 40 seconds). Including the last rest makes it 4 minutes. Allow a transition before any next activity and a separate easy finish.

For a strength-focused block instead, plan two sets of six reps at 2–1–3. The timed reps take 2 × 6 × 6 = 72 seconds. Add one 90-second rest between sets for 2 minutes 42 seconds, plus time to set up and put equipment away. These are estimates: pausing for technique, adjusting equipment, or taking longer recovery will change the real duration. Build the corresponding plan in the Gym timer.

Start with an activity and duration you can do with control. If work intervals leave too little room to recover or technique deteriorates, shorten the work interval, lengthen the rest, reduce the number of rounds, or select an easier activity. For a lift, reduce the load or reps, increase rest between sets, or choose a tempo you can follow without rushing or straining to meet the clock.

Keep a warm-up, equipment changes, and a finish outside the calculated timer block unless you explicitly account for them. Pause or stop if you feel pain, dizziness, or otherwise unwell. A timer is a pacing aid, not a way to assess whether a particular exercise is appropriate for you; seek qualified guidance if you are uncertain about a movement or have health concerns.