What is your "best" and when should you consider adjusting in? Simply put:
Notice the emphasis on repeatedly and complete control.
Just because you can repeatably run at this speed under complete control doesn't mean it isn't difficult! You should feel you are pushing yourself to the max and firing on all cylinders when you are running at your personal best. The only reason it's not described as a 10 out of 10 is that we want to ensure there is a small buffer for correct form and safety.
If you were running from a bear, then by all means, throw form out the window and just move as fast as you can! But we aren't running from a bear, so we add a slight buffer for safety.
Your personal best is not the fastest speed you will ever run. Instead, it's used as an anchor point, which the workout adapts to. There will be moments when we will go faster than your personal best in order to help you progress and get out of your comfort zone, but rest assured knowing:
The app will set your initial personal best based on the questions you answer during onboarding, but you can (and are encouraged to) adjust it at any time.
We suggest using your personal best as a lever to adjust the difficulty of the workout for you. The workouts are focused on balance, but they are not all created the same! Depending on the person, some may struggle with incline but find longer training intervals a breeze, and of course, some may just not be feeling motivated that day!
That said, because the workouts are mathematically balanced, there shouldn't be any workouts that feel significantly too easy or too hard compared to other workouts at the same personal best. If you find yourself making adjustments more than +-1 your usual personal best, please reach out to us so we can dive deeper.