Sand Resistance Training Interval Timer

How it works

An interval session alternates a work phase, when you sprint, jump or drive hard through the sand, with a rest phase, when you walk or stand and let your breathing settle. This timer counts down one phase at a time, then moves to the next phase and the next round until the rounds you set are complete.

At every phase change the timer plays a short beep generated in your browser with the WebAudio oscillator — no audio file is downloaded. The work phase beep is a higher tone and the rest phase beep is a lower tone, so you can tell them apart without looking at the screen. The timer uses a single countdown: pressing Start while it is already running does nothing, so two intervals can never run at once, and Pause freezes the exact remaining seconds.

Because sand adds resistance, a work interval on sand feels harder than the same interval on a hard surface. A sensible starting point is 30 to 40 seconds of work with 20 to 30 seconds of rest for 5 to 8 rounds, with a gentle warm-up and cool-down either side. If you cannot hold good form in the last rounds, shorten the work interval rather than pushing through with poor technique.

How to use your result

Set your numbers before you start, put the device where you can hear it, and train to the beep rather than watching the clock. When the session ends, note how the last round felt: if it felt easy, add a round or a few seconds of work next time; if form broke down, keep the same numbers until they feel comfortable.

Related guides

• Sand Sprint HIIT Workouts for Beginners
• Interval Training on Soft Surfaces: A Practical Guide
• Building a Beach Workout Routine That Lasts