The 90-day challenge: a week-by-week bodyweight plan
Proof90 is a 90-day bodyweight challenge your phone verifies. Every day has push-ups, squats and a walk, plus one honor-system habit. The push-ups and squats are counted by your camera, the walk is confirmed by your phone's sensors, and anything it can't measure is labelled honestly. No equipment, and no account.
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What a day looks like
| Task | How it's proven |
|---|---|
| Push-ups | Counted by the camera, live, on your phone |
| Squats | Counted by the camera, live, on your phone |
| Walk | Confirmed by your phone's motion sensors |
| Stay within your food rules | Honor system, labelled as such |
Six days a week are training days. The seventh is a longer walk and nothing else.
The plan, week by week
Targets are sets × reps. The plan starts deliberately easy and builds slowly, so the first weeks are about turning up every day, not about testing you.
| Week | Days | Push-ups | Squats | Daily walk | Long walk day |
|---|---|---|---|---|---|
| 1 | 1–7 | 3 × 4 | 3 × 8 | 15 min | 30 min |
| 2 | 8–14 | 3 × 5 | 3 × 10 | 15 min | 30 min |
| 3 | 15–21 | 3 × 6 | 3 × 12 | 20 min | 35 min |
| 4 | 22–28 | 3 × 7 | 3 × 14 | 20 min | 35 min |
| 5 | 29–35 | 3 × 8 | 3 × 15 | 25 min | 40 min |
| 6 | 36–42 | 3 × 9 | 3 × 16 | 25 min | 40 min |
| 7 | 43–49 | 3 × 10 | 3 × 18 | 30 min | 45 min |
| 8 | 50–56 | 4 × 9 | 4 × 15 | 30 min | 45 min |
| 9 | 57–63 | 4 × 10 | 4 × 16 | 30 min | 45 min |
| 10 | 64–70 | 4 × 11 | 4 × 18 | 35 min | 50 min |
| 11 | 71–77 | 4 × 12 | 4 × 20 | 35 min | 50 min |
| 12 | 78–84 | 4 × 13 | 4 × 22 | 40 min | 55 min |
| 13 | 85–90 | 4 × 14 | 4 × 24 | 40 min | — |
For the push-ups on their own, every day of the 90 in a table you can print, with a rule for choosing full, knee or hands-raised push-ups, see the 90-day push-up challenge.
The program is a starting point, not a prescription for everyone. Talk to a doctor before you begin, especially if you have a heart condition, an injury or haven't exercised for a while, and stop if you feel pain, dizziness or shortness of breath.
The rules
These are what make a streak mean something.
- The calendar is the program. Day 1 is the day you start; day 2 is the next day, whatever happened. There is no pause and no restart.
- You can only record today. Yesterday can't be back-filled.
- Missed days stay missed. They stay on your calendar.
- One grace day every 14 days, seven across the 90. You have to spend it on purpose, on yesterday, and a graced day is never shown as done.
- Verified and on-your-word never look the same. If the camera or sensors couldn't confirm a task, you can log it on your word and it's recorded as exactly that.
Weekly progress photos
Once a week the app helps you line up a photo with last week's as you take it. They become a before-and-after timelapse, built on your phone. The photos never leave your phone.
What it costs
The first week is free on Android. On iPhone the annual plan starts with a 7-day free trial. After that Proof90 is a monthly or annual subscription. The price is shown in the app before you buy, and you can cancel any time in your Apple Account or Google Play settings.
Questions
Do I need equipment?
No. Push-ups, squats and walking. Prop your phone up so the camera can see you.
What if I miss a day?
It stays missed. If you missed yesterday and haven't used this fortnight's grace day, you can spend it, and yesterday is then marked as graced, not done.
Can I do it offline?
Yes. Counting and logging work with no signal and sync later.
How is this different from other 90-day challenge apps?
Many challenge apps are a checklist: you tick a box. In Proof90 anything the phone can measure is measured, and everything else says it's on your word. See how verification works.
Is it a "transformation" program?
No. It doesn't promise a look or a number. It gives you a plan, proof that you did it, and a before-and-after that is yours.