Most training apps rely only on one RPE score, how hard the session felt overall. But athletes know not all fatigue feels the same.
A heavy squat session torches your muscles but barely challenges your lungs, while a tempo run does the opposite. And sprinting? It does both.
By asking you to rate both muscular effort and respiratory effort, PEAK captures the true stress of your training.
This matters because different types of fatigue load your system in different ways. Ignoring one underestimates the real cost of a session. If you only used respiratory effort, strength sessions would look easy on paper when they’re anything but.
Separating the two allows PEAK to balance gym, field, and endurance work on the same scale, making Training Load more accurate.
The end result?
Your PEAKScore reflects reality, not just cardio. This dual approach ensures that when you review your week, your muscles, lungs, and nervous system all get the credit (and recovery) they deserve.
If you’d like to dive deeper into the science behind this approach, we recommend watching this interview with Dr Shaun McLaren: