The weights
- Participation 35%
- Consistency 25%
- Improvement 25%
- Mutual support 15%
JESS MOVEChallenges
Inclusive competition
The fittest person in the room
cannot win this on their own.
A leaderboard that rewards capability is always won by the same person, and everybody else stops opening the app in week two. So capability is not weighted down in the scoring function — it is absent from it. A ten-year-old, a wheelchair user and an eighty-eight-year-old contribute on exactly the same four terms as a marathon runner, and the runner has no lever the others lack.
Team Score
Four terms, and none of them is output.
| Term | What it measures | Why it is there |
|---|---|---|
| Participation 35% | The share of the team who did anything at all this week. | It is the only term a large team cannot win by carrying one strong member. |
| Consistency 25% | How evenly effort is spread across the days, per person. | Rewards the person who does two minutes on five days over the one who does a burst. |
| Improvement 25% | Movement against each person’s own previous fortnight. | Everyone starts from where they are, so everyone has the same headroom. |
| Mutual support 15% | Encouragement given, sessions joined, teammates brought back after a lapse. | Makes helping somebody else the highest-leverage thing you can do. |
The guard
Capability is rejected at the boundary, not discounted inside it.
teamScore() inspects the keys it is handed and throws if any of them resembles raw output. Fourteen field names are refused outright, so a well-meaning integration cannot quietly reintroduce a fitness leaderboard.
Rejected field names
throws- steps
- distance
- pace
- speed
- vo2max
- calories
- kcal
- weight
- bmi
- heartRate
- watts
- reps
- load
- personalBest
Substring matching, so weeklySteps and avgHeartRate are caught as readily as steps. Asserted in continuous integration against every name on the list.
Two teams, scored by the engine
out of 100This is the whole design in one chart. The team with three genuinely exceptional athletes scores 32.8. The team where everybody manages two minutes most days scores 83.5.
Contribution ceiling
18%
No individual may supply more than this share of a team's total. Our simulated superstar on a two-person team was capped at 18%.
Median team reaches
70
Against a target of 60. A challenge a team of entirely median people cannot win is not shipped — this one passes.
Leaderboards
Nobody is ever shown their position from the bottom.
Loss framing works, and it works by making people feel worse. Six rules govern every ranked surface in the product, and they are asserted as a build gate rather than left to a design review.
Always true
- Nobody is ever shown their position from the bottom.
- Below-median positions are not rendered at all, for anyone.
- A team’s standing is visible; an individual’s ranking within it is not.
- No leaderboard may be built on weight, body composition or appearance.
- No open leaderboard exists in Explorer or Teen Mode.
- Leaving a challenge is one tap and costs nothing.
Withdrawal costs nothing
- a reported flare-up or illness
- a bereavement hold
- a new caring responsibility
- three consecutive days of declining every prompt
- a safety escalation of any kind
- a self-reported low-energy period
What your absence costs your team
measured0
Nothing. Participation is measured against active members rather than the roster, so stepping out during illness, a flare-up, a bereavement or a new caring responsibility cannot drag your colleagues down. The engine withdraws you automatically on any of the triggers above — you do not have to ask, and nobody is told why.
The library
Eight challenges, and one of them has no losing team.
4 WEEKS
Meeting Breakers
Workplaces with a back-to-back culture
- Won by: The department that interrupts the most long sitting blocks, per head.
2 WEEKS
Lunchtime Lift
Any team, any size
- Won by: Share of the team who move between 12:00 and 14:00 on any given day.
A HALF TERM
School Class Quest
A class, with the teacher triggering breaks
- Won by: Class participation. No pupil is ever named in a ranking.
A WEEKEND
Family Weekend Expedition
A household across up to four decades
- Won by: Every profile contributing at least once. Nobody can finish it alone.
6 WEEKS
Care Home Garden Journey
Residents and carers together
- Won by: Sessions completed, seated and standing counted identically.
A SEASON
UK City Movement League
Councils and public-health programmes
- Won by: Participation rate by city, above the k-anonymity floor.
1 MONTH
Charity Movement Month
Anyone; a sponsor converts participation to a donation
- Won by: Collective participation. There is no losing team.
2 WEEKS
The Return
Teams with people who lapsed
- Won by: Teammates brought back. Only mutual support scores.
Competition is opt-in everywhere, and there is no open leaderboard at all in Explorer or Teen Mode.
Start one this week.
Create an account and a challenge takes about a minute to set up. For a whole workforce or a school, a pilot is the better route.
Free to create. 150 AI credits a month for 2 months, then AI features need a plan — everything that is not AI carries on either way. Premium is £5.99 a month and cancels in one click. Under 18 a guardian confirms before the account opens.