feat: Automatic coaching for set goals

[Mafeffe]

Since the app collects your training data it should be able to notice when you're stagnating in an exercise over time (long timescale). Daily form would of course influence your data in the short term, but over several months your average exercise weight and/or reps should increase in order to see muscle/strength growth. If the app notices stagnation, it could suggest ways to combat this, for example by suggesting a slight weight increase, slightly more reps, or even a weight decrease in order to get more reps. More sets could also be an option, though one has to be vary of getting junk volume. Even just a reminder that you have stagnated in this specific exercise could be enough to push you further.

Maybe the app should have you set what your goals are. If your goal is to build muscle, this type of coaching would be great, and perhaps the app would suggest that you do somewhere between 6 to 12 reps. If the goal is to gain strength it could instead suggest a lower number of reps, but more sets. If the gain is to lose weight then stagnation isn't that important, but tracking how much weight you've moved (and therefore kcals burned) would be good.

[Mafeffe]

Maybe a graph to visualise progress somewhow would be good. I think that might be very motivating for the user. Sometimes progress can be so slow that it's hard to notice. So the app telling you you have been getting stronger the last few months even though it doesn't feel like it could help.