Every benchmark comes from somewhere. Here is where.
These numbers are in the app, on the cards, with their source written underneath. They are not there to impress: they are there so you can go and read what they rest on, and decide for yourself what to make of them.
Your body index
Example
You are between 20 and 25, the range where observed mortality is lowest.
Global BMI Mortality Collaboration (2016), Lancet: 239 studies, 10.6 million participants.
7,000
steps a day
The measured inflection point. Against 2,000 steps, observed mortality there is markedly lower.
Ding et al. (2025), Lancet Public Health, 57 studies
7h
of sleep
The trough of a U-shaped curve. Each hour above weighs less than each hour below.
Yin et al. (2017), J Am Heart Assoc
208 − 0.7 × age
your maximum heart rate
And not "220 minus age", which underestimates it past 40.
Tanaka et al. (2001), 351 studies, 18,712 subjects
46 studies
on resting heart rate
Your resting heart is read against that base, and against your own weeks, not against a round number.
Zhang et al. (2015), CMAJ, 1.2 million participants
0 to 3
reps in reserve
Going to failure every time adds nothing, and tires you markedly more.
Robinson et al. (2024), Sports Medicine
When the literature does not settle a question, the app does not settle it either. What we will not tell you.