Pick up any mainstream health tracker, and you are greeted with a number out of 100: a "Sleep Score," a "Readiness Score," or a colored ring.
At first glance, a single summary number feels intuitive. But after watching how people used the score in ARC 1.x, we realized something fundamental: a score out of 100 invites you to optimize the score, not your day.
Here is why ARC 2.0 deliberately eliminated the sleep score, rings, streaks, and badges.
1. Orthosomnia and the Anxiety Loop#
When you wake up feeling relatively rested, look at your tracker, and see a score of "58/100," your brain immediately shifts into a state of perceived fatigue. Sleep researchers call this orthosomnia (Baron et al. 2017, Journal of Clinical Sleep Medicine): a perfectionist quest for a tracker's approval that can itself cause stress and sleep anxiety. If you've compared trackers, our Oura vs ARC and WHOOP vs ARC comparisons go into how the approaches differ.
Retrospective scores grade you like a school report card. But knowing you had a "bad night" at 7:00 AM does not give you an action; it gives you anxiety.
2. A Score Does Not Tell You What to Do#
A score is a verdict, not an operating system.
- If your score is 64, should you drink an extra espresso? (Only if it still fits tonight's caffeine cutoff).
- Should you skip morning sunlight? (No, that delays your cortisol anchor).
- Should you force yourself to take a nap? (Only if it fits your afternoon dip).
What people lack is not data about last night—they lack a clear model of today, and a single high-leverage action to take right now.
3. Mechanism, Never Verdict#
The guiding philosophy of ARC 2.0 is: "This is adenosine, not laziness."
ARC will never grade your sleep or congratulate you with a digital badge. If you had a rough night, ARC's sleep-debt recovery loop kicks in: it explains why today feels heavy and gives you one ask for the day, without judgment.
4. What ARC Measures Instead#
Instead of a sleep score, ARC 2.0 measures what changed, from your one-tap energy check-ins:
- Afternoon crashes per week: counted from your one-tap check-ins, so you can see whether the number is actually moving.
- 14-day strips: whether you got your morning light and held your caffeine cutoff, day by day.
- Dip timing: after about ten days of check-ins, ARC measures when your afternoon dip really lands, so you can schedule deep work around it (why the 2 PM crash happens).
- What each habit changed: five-day single-habit experiments with honest verdicts, including "no difference".
You don't need a wearable ring or a grade out of 100 to feel great. You just need to know why you feel like this right now, and the one thing worth doing about it.