Ryan Woodruff
Several years ago, I was coaching between 12 and 20 swimmers at practice by myself, and I was looking for a way to time a series of 25s off the blocks. I wanted a system that could provide an audible “take your marks” command followed by a starting beep and repeat exactly 10.00 seconds apart. This would allow me to stand at the opposite end of the pool and accurately time the swimmers coming to the wall without having to verbally start each successive group. Below are the instructions for you to replicate the system I created.
I used a free iPhone app, a Bluetooth speaker, and my iPhone to create a system to make me a more efficient and accurate coach when we do quality sets.
First — the app. It is called IntervalTimer and is available for free in the iPhone App Store. I don’t know if it also exists for Android.

Next, I got a Bluetooth Speaker. There a lot of options available. I used the Ion Pathfinder Rugged Bluetooth Portable Speaker and set it where it won’t get wet. If you get a waterproof one, it works to set it between the starting blocks. My speaker was able to connect to my phone from over 50m away, which was helpful for long course season.

In the app, I created a timer using the HIIT template. I created 2 intervals – one called “Go” and one called “Take Your Mark.” I also chose to do 3 sets (you can choose whatever number you like), toggled “Repeat” to ON, and set it for “x100”. This creates a loop that would do starts for 50 minutes non-stop, more than long enough for most of our quality sets. Make sure you have all the settings as I have it pictured.

When setting up “Go”, and “Take Your Mark,” I set the sound settings as pictured below.


These settings show a countdown from :08 to :00, at which time the app says “Take your marks” and two seconds later sounds a loud “ding” sound.

A few final tips for usage:
- Make sure you are connected to speaker via Bluetooth and that your phone maintains a clean line-of-sight to the speaker.
- When you start the timer, it takes about a second for the app to begin. This is only important if you are syncing it up to your pace clock – just hit start when your pace clock says XX:X9.
- Be sure to set your phone on “Do Not Disturb” to avoid any awkward phone calls that disrupt your timer.
- I DO NOT RECOMMEND USING THIS SYSTEM WITH 12 & UNDERS. Make sure that all swimmers understand that if they dive in and their goggles come off, they should not stop — there is another swimmer coming 10 seconds later. MAKE SURE ALL SWIMMERS UNDERSTAND THE SET AND HOW TO SAFELY USE THIS SYSTEM.
If you use this system and have any questions or feedback, please let me know at swimmingwizard@gmail.com.