Lab Notes: Lapping Avery & Bellardi Pools

World Champ Tech’s workout apps are never designed in a sterile laboratory. Real world testing of the workout apps provides a deeper understanding on the design requirements for each of the apps. Design and development of the Swim+ app took place primarily at Stanford University at the Avery and Bellardi pool complex. Avery pool is a 50 meter by 25 yard pool that can be configured for LCM laps (long course meters) or SCY laps (short course yards). Bellardi pool is a standard Olympic-sized pool that has been used for multiple collegiate and national championships. Olympic-sized pools are 50 meters by 25 metes, and Bellardi can be configured for either LCM laps or SCM laps (short course meters).

Tens of thousands of laps under varying conditions and pool configurations have provided a rich body of design information for the Swim+ app. A primary insight was the visibility of different color text on the Apple Watch screen while underwater. Blue tinted swim googles - a popular choice because they reduce surface glare - filter light such that yellow text on a dark screen is challenging to read under water. Extensive testing showed that white text on a dark background provided the best readability.

Endless lapping at Stanford, with the multiple pool lap configuration on offer, also help uncover a flaw in the data reported by the Apple workout data system. When you select a pool lap length, Apple assumes that you only change stroke types at the end of each lap. In most case this is true. For example, when you swim individual medley in a 25 yard (SCY) configured pool, a 100 yard IM consists of 25 yards, or one lap of the pool. Apple correctly reports a 100 yard IM in a 25 yard pool as 100 yards. But, it’s possible to swim a 100 meter IM in a 50 meter (LCM) configured pool by changing strokes mid-lap. Unfortunately, Apple assumes that each each stroke change is a separate lap, and reports 200 meters for the distance. This error also suggest impossibly fast lap times since the stated distance for each lap is 50 meters, even though in reality you only swam 25 meters. Any swimmer who can finish a 100 meter IM with a 25 meter freestyle segment under 20.91 seconds would have a reported 50 meter lap faster than the world record.

Steam rises off Stanford Avery Pool before a swim on a cold morning. Avery pool is configured for SCY (25 yards)