METHOD & LIMITS · UPDATED OCTOBER 18, 2026
How an entry becomes LIFE time.
Lifetime uses a common score so movement, selected foods, and water can appear in one personal ledger. We call it LIFE time, or LTE. Minutes, hours, and days are display units for that score. They are not a conversion from a habit into additional lifespan.
The exercise calculation currently uses version preview-0.3.0. The curves, weights, thresholds, and rewards below are provisional product choices. The score has not been clinically validated or formally calibrated against health outcomes.
What evidence supports — and what we choose
The World Health Organization describes benefits of regular physical activity and the role of fruit and vegetables within a healthy diet. Those broad principles provide context for recording these habits. They do not establish Lifetime’s formulas or support a claim that an entry earns a specific amount of life.
Our choices include the time-based score, activity comparisons, bonus thresholds, food portion rewards, and water points. The linked guidance does not validate or endorse those choices. Lifetime does not account for all the factors that affect a person’s health.
Exercise: a daily base, then bonuses
Entries are grouped by date and activity type. The app calculates each type’s daily base, adds the bases together, and then calculates consistency and variety contributions. Original entries remain visible in history.
- Walking
- Daily walking-only steps and age. If measured steps are absent, distance or duration supplies a labeled estimate. The curve levels off at an age-dependent step count.
- Running
- Daily distance and the highest recorded running effort for that date. The distance contribution is 12 × the square root of kilometers, capped at 60 LIFE minutes, before the effort adjustment.
- Cycling, swimming, and yoga
- Active time and effort, using a different diminishing-return curve for each activity. Optional cycling and swimming distance does not currently increase the score.
- Strength
- Duration and effort, with an optional working-set adjustment. More time gives diminishing returns; sets describe the individual session.
- Ball sports
- Active time, effort, and a small sport-specific factor. The factor is a product approximation; it is not an individual energy-expenditure measurement.
Consistency and variety
A qualifying day contains at least one activity type reaching its daily threshold: walking 20 minutes, running 10, cycling 15, strength 20, ball sports 15, yoga 20, or swimming 15. A date counts once, even if several types qualify. These are scoring thresholds, not exercise prescriptions.
Consistency uses consecutive completed Monday–Sunday weeks with at least three qualifying days. The current unfinished week does not add a completed-week bonus. The consistency level rises at 2, 4, 8, and 12 consecutive qualifying weeks.
Variety looks at qualifying activity types over the entry date and the previous 13 days. One type alone gives no variety bonus. A similarity weighting gives less additional credit to closely related movements. Frequency and variety share a bounded bonus calculation; they are not two independent rewards added at their maximum.
Food: portions and distinct foods
For each date, fruit earns 5 LIFE minutes per 80 g up to 10, and vegetables earn 5 per 80 g up to 15. Partial portions count proportionally. Each distinct food totaling at least 40 g qualifies for variety; each qualifying food after the first adds 1 minute, up to 4. The combined daily food maximum is 29.
Worked example: 80 g of apple and 80 g of carrot on the same date earn 5 fruit minutes, 5 vegetable minutes, and 1 variety minute: 11 in total. Entering the apple as two 40 g portions leaves the result unchanged. This is an illustration of the score, not a recommended meal.
Water: a separate capped product reward
Daily water time is the smaller of total milliliters divided by 250 and 4. For example, 750 mL gives 3 LIFE minutes. The cap exists to limit points, not to set a drinking target or assess hydration. Recording more after reaching it can still add history without adding time.
Why a correction can change later totals
Your balance combines daily exercise, food, and water scores. It is not a sum of separate full-day rewards for every entry. Correcting a past exercise entry may change whether that date qualifies and can therefore change later consistency or variety bonuses. The preview shows the net ledger change.
Keep original sessions and portions accurate. Daily aggregation prevents duplicate full rewards for identical split portions, but changing effort, set counts, names, or dates changes the inputs and may change the result. A record with no added points can still be useful.
Read the score with its limits
Entries are self-reported and estimates can be wrong. The food log covers selected foods, not your complete diet, and the water log does not assess your body’s needs. The score cannot compare two people’s health, diagnose a condition, measure fitness, or predict longevity. Use it to reflect on your own recorded habits rather than as a reason to chase a higher number.
Sources and further reading
- WHO: Physical activity — public-health context for regular movement; not a source of the LTE conversion.
- WHO: Healthy diet — context for a varied diet; not a validation of Lifetime’s portion rewards.
Continue with How it works or the exercise, food, and water recording guides. Questions about the method can be sent to enceluo@gmail.com.