[jreynar]

I've built a handful of things, most of which mirror commercial / open source products but for which I had particular requirements that were hard to satisfy (like a wine cellar tracker where I wanted recommendations about purchases from an email list). The one that seemed most unique was a fitness / health tracking thing. There are lots of apps for logging data (like Strava), lots of coaching apps (training peaks and others), including AI coaching apps, and tools focused on recovery (whoop), but I couldn't find anything that would help me understand the drivers of my level of fitness. I run, bike, lift weights and do Pilates and wanted to understand where I got the most bang for the buck in terms of cardio and VO2 max. Turned out to be a fairly tricky proposition with a detour through understanding the limitations of measuring your heartrate with an apple watch compared to a chest strap. But I ended up getting a pretty good picture of how best to use limited fitness time in both the summer (when outdoor activities are easy) and winter (when I'm stuck inside more often due to snow, cold weather and gritty roads that making running questionable). I might open source it for other people who are as nerdy about fitness as I am...