Each zone starts at 100 points — “fully supported.” Every risk factor you mark in the self-check subtracts a fixed number of points. The zone card shows each factor that fired and its exact contribution — the logic is not hidden.
Age and other non-modifiable factors are never penalised on their own — otherwise a healthy older person would always be “red.” Instead, age acts as a multiplier (×1.0–×1.3) on mechanical factors such as excess weight or a running-load spike: the same wear costs joints more with age.
The 0–100 total maps to four colour bands: 85–100 green, 65–84 yellow, 40–64 orange, 0–39 red. The colour means how supported a zone is — not a diagnosis.
“Lifestyle age” is a separate educational index: calendar age plus or minus the contribution of habits, using estimates from large cohort studies. It is not a medical measure — its job is to make the effect of habits tangible.
Warning signs (chest pain, breathlessness at rest, night joint pain and others) are never converted into points: the service addresses them separately, visibly and calmly, explaining why a doctor’s visit shouldn’t wait. Such messages are never monetised.
Review status
Thresholds and weights are drawn from the open clinical guidance and studies listed below and are undergoing physician review before full launch. If you are a clinician and can make this more accurate — write to us.
Sources
WHO Physical Activity Guidelines, 2020Activity norm: 150–300 min/week + 2 strength sessions
AASM / Sleep Research Society, 2015Adults are recommended 7+ hours of sleep
Drake et al., J Clin Sleep Med, 2013Caffeine 6h before bed disrupts sleep
Jha et al., NEJM, 2013Smoking costs ~10 years; quitting by 40 wins ~9 back
Doll et al., BMJ, 200450-year British doctors cohort: harms of smoking
Lauersen et al., Br J Sports Med, 2014Strength training roughly halves overuse injuries
Gabbett, Br J Sports Med, 2016Sharp load spikes (ACWR >1.5) raise injury risk
Messier et al., Arthritis Rheum, 2005−1 kg body weight ≈ −4 kg knee load per step
Alentorn-Geli et al., JOSPT, 2017Recreational runners get less osteoarthritis than sedentary people
Ekelund et al., Lancet, 201660–75 min of daily activity offsets sitting time
Milewski et al., J Pediatr Orthop, 2014Sleep <8h linked to higher athlete injury rates
Li et al., Circulation, 20185 lifestyle habits ≈ +12–14 years of life
ESC 2018 / ACC-AHA 2017Blood pressure categories
Tanaka et al., JACC, 2001Max heart rate ≈ 208 − 0.7 × age
Mifflin & St Jeor, 1990Resting metabolic rate formula
Ashwell & Gibson, 2016Waist-to-height < 0.5 as a risk anchor
Morton et al., Br J Sports Med, 2018Protein ~1.6 g/kg for muscle growth
NHS / ACR red flagsStandard musculoskeletal red flags
Livingston et al., Lancet Commission, 202414 modifiable dementia risk factors: hearing, vision, social contact, activity and more
Inman et al., Mayo Clin Proc, 2009Erectile dysfunction as an early marker of cardiovascular risk
EFSA, 2010Fluid anchor: ~2.0 L/day for women, ~2.5 L/day for men (food included)
NICE NG123 / Dumoulin, Cochrane 2018Pelvic floor training is first-line for stress incontinence
This service is informational, is not a medical service and does not replace a doctor’s consultation. If you have symptoms, see a specialist. In an emergency, call your local emergency number.