There is a design problem with the use of the back button as: "lap" during an activity or "skip" during a training.
Some times, in the coach plan, the lap is not displayed as usual (don't know why) and so if you press lap by instinct (as usually), you skip the whole pace or race! Very VERY annoying as you can not revert...
More, if you want to take a lap time by reflex, you can't as the lap button is dedicated to the training and means "skip". And there is nothing you can do to cancel...Very VERY annoying as you can not revert...
Don't even think about disable the lap button (new parameter) as then, you will not be able to go thurther the training. No lap, no skip!
Can you improve the User Experience Design to be less confused ?
Regards