Money is a marker
The deposit should make the commitment concrete, not turn movement into punishment.
Our story · London
Why is it easier to break a promise to yourself than to anyone else?
FitBond began with the gap between intention and action: the run you mean to do, the class you keep moving, the streak that never quite becomes routine.
A commitment device makes that future decision concrete now. FitBond combines a measurable goal, a chosen deposit, and automatic verification—then applies the rules agreed at the start.
Four things we believe.
The rules come first
Goal, cadence, verification, fees, cancellation, and settlement are visible before confirmation.
The source is the referee
Progress comes from the tracker or location source connected to the Bond—not a manual claim.
Evidence has limits
Commitment devices can help in some contexts. They are not a guarantee and they are not medical advice.
The science
Three papers worth reading carefully.
The strongest version of the evidence includes sample sizes, time horizons, and limitations—not just the headline number.
47.4%
Volpp et al. · JAMA · 2008 · DOI 10.1001/jama.2008.804
Deposit contracts improved a short-term target in a small trial.
Fifty-seven adults were randomized across control, lottery incentive, and matched deposit-contract groups for 16 weeks. 47.4% of the deposit group met the 16 lb target versus 10.5% of control. The between-group difference was not statistically significant at seven months, so the study supports short-term potential rather than a durable guarantee.
Read the paper ↗18–254
Lally et al. · European Journal of Social Psychology · 2010 · DOI 10.1002/ejsp.674
Habit formation varied dramatically between people and behaviours.
Ninety-six volunteers repeated one behaviour in a stable context for 12 weeks; 82 supplied enough data for analysis. Among fitted individual models, time to 95% automaticity ranged from 18 to 254 days. Missing one opportunity did not materially derail the process.
Read the paper ↗Steeper
Kahneman & Tversky · Econometrica · 1979 · JSTOR 1914185
Prospect theory describes losses as more salient than equivalent gains.
The foundational paper argues that people evaluate gains and losses relative to a reference point and that the value function is generally steeper for losses. It is a theory of decisions under risk—not a clinical trial of fitness deposits, and the original paper does not establish a universal “2×” multiplier.
Read the paper ↗Who we are
A small London team building the tool we wanted on the days motivation disappeared.
FitBond is being built deliberately: clear rules, automatic verification, and honest language around money. For product, research, or partnership questions, write to hello@fitbond.co.uk.
Willpower is variable. Make the commitment visible.
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