Riven App Uses Apple Watch to Track Muscle Failure During Workouts

Here's an uncomfortable truth about the gym: most people never actually train to failure.

They stop on discomfort, boredom, or a rep number they picked in advance — usually a few reps before the muscle is actually done.

Since pushing close to failure is what makes muscle grow, that gap is why so many people train for years and look the same.

Until now the only way to measure this was lab equipment — expensive, impractical, and definitely not something you'd use at a commercial gym.

So I built Riven on something millions of people already wear: the Apple Watch.