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March 30, 2026 · by Cyril

Timed exercises and rest timers: why your plank deserves better tracking

You’re holding a plank. 45 seconds. Arms shaking, staring at the floor, counting in your head. “38… 39… 40…”

Wait, was that 40 or 42? When did you actually start counting?

Timed exercises are the forgotten stepchildren of fitness tracking. Planks, stretches, isometrics, weighted holds — they make up a huge chunk of training. But without a reliable timer, you’re training blind.

The problem with manual timers

Most workout apps are built for reps and weight. You log “3x10 at 80 kg” and move on. But when you have a time-based exercise, you end up:

  • Opening a separate stopwatch app
  • Hitting “start” while getting into position
  • Trying to read the screen during a plank (good luck)
  • Forgetting to log the result afterward

That’s not a workflow. That’s friction.

Which exercises need timers

More than you’d think:

  • Planks (front plank, side plank, hollow hold)
  • Stretches (each position held for X seconds)
  • Isometrics (wall sit, dead hang, pause squat)
  • Weighted holds (plank with vest, farmer’s carry for time)
  • Stationary cardio (treadmill, bike, rower — when tracking by time)

Anything measured in seconds instead of reps needs a timer. Not a separate stopwatch. A timer built into the tracking.

How it should work

You tap “Let’s go.” The timer starts automatically. You focus on your exercise, not your screen.

When time is up:

  1. Your phone vibrates (even with the screen locked)
  2. The set is automatically recorded
  3. The rest timer starts immediately

You didn’t touch anything. Zero interruption. You move to the next set when rest is done.

Rest starts before the button

Here’s another common problem. After your last set of planks, you land on the feedback screen. You rate your difficulty, check your summary. Meanwhile, you’re already resting, but no timer is running.

The result: you tap “Next exercise,” the rest timer starts, and you wait another 90 seconds when you’ve already been resting for a minute. That’s wasted time.

The fix: the rest timer starts the moment your last set ends. While you’re rating difficulty, rest is ticking in the background. When you tap “Next,” if rest is done, you go straight to the next exercise.

What about a locked screen?

This is the question everyone asks. You’re doing a plank, you put your phone face-down, the screen locks.

Two options:

  • Keep the screen on: wake lock prevents sleep (enabled by default in RepStack, toggle it off in settings if you prefer)
  • Push notifications: even with the screen locked, you get a “Timer done!” notification with vibration

The idea: you should never have to look at your phone during an isometric exercise.

Progressive overload for timed exercises

Progressive overload applies here too. But instead of adding weight or reps, you add seconds:

  • Week 1: plank 3x30s
  • Week 2: plank 3x35s
  • Week 3: plank 3x40s

And when you plateau on time, switch to weighted holds:

  • Plank 3x30s with 5 kg
  • Then 3x30s with 10 kg

RepStack’s AI handles this progression automatically, whether it’s time, weight, or distance. Each exercise type has its own progression logic.

Getting started

If you do planks regularly but don’t track them, start now:

  1. Create a session type with your core exercises
  2. Set a realistic target time (30s if you’re starting, 60s if you’re comfortable)
  3. Launch the session — the timer handles everything

Try RepStack and create your first timed workout session.