Set the timer to 172 seconds

How to use the online timer

A proper warm-up doesn't need to be long, and 172 seconds is enough to get your muscles moving and your heart rate up before you jump into the main session. Start the clock, run through a few dynamic stretches or some light cardio, and let the beep tell you when to switch rather than cutting it short because you're keen to get started. Rushing this bit just costs you later.

Using it is as simple as it sounds: hit Start and the countdown takes over from there. Keep the browser tab open while it runs, since the timer only keeps counting while the page stays loaded, and pause or reset it any time if your plans change. When time's up, a sound plays to let you know, so you don't need to keep glancing at the screen.

A mechanical timer needs to be wound and a phone timer needs the phone unlocked, but this one just needs the page you already have open. It sits inside your browser, ready whenever you are, and it's the same tool whether you're on a laptop or a tablet in the kitchen. Free, with nothing to install or sign into, it's built to get out of your way and count. If you would rather say put a timer on for 172 seconds, that works too — press Start and the page does the rest.