My dear wife just forwarded me an advertisement for Form swim goggles, the ones that display metrics like time and distance in a heads up display. When she does this I take it as permission to buy. Not bad, since these goggles cost plenty. The only reason I don't already have them is they do not offer corrective lenses. Now that I swim exclusively open water their value would be questionable because they get pace data from the Garmin watch, and stroke by stroke pace data is wildly inaccurate.
I clicked through to the Form site anyway and was bombarded by glossy offers of success, provided I join their training program for a hefty $200+ per year. What does that give you? Training plans for a variety of triathlons, access to a huge library of swim workouts, and a forum. The triathlon plans only cover swimming.
There are similar programs for runners. One I tried did include a monthly live q&a, and the coach did an excellent job of offering solutions to member's questions. Still a lot of money for one size fits all plans.
Previously I have written about the Frontier X HRM. The app that goes with it offers AI driven feedback after every workout. Typically "Nice job. Next time, go a little longer." Woefully inadequate.
I use Inside Tracker. Of course I have it connected to my Garmin. After every workout I get a nutrition focused comment, how much fluids I might need, nutrients, and recipes that put those numbers into practice. I like that.
And now Garmin is getting into the act. I finally got used to seeing their post workout recovery advice. Just how long you should rest. Some of the newer models will suggest workouts based on your recent activity.
My point is that in today's fitness marketplace, consumers are bombarded with the kind of training advice that until recently was only available from personal trainers and coaches. The quality is all over the map, and there isn't much agreement. The biggest drawback is that they can't see the big picture. A good coach will know all about everything you are doing, as well as non sport specific stressors like business travel or illness in the family. A coach can take the mountain of data today's sensors produce and make sense off it and leave the athlete more time to do other things, like sleep.