Blood pressure: the two numbers explained
Systolic, diastolic, 120/80 and 140/90: what the two blood pressure numbers mean, where high begins, how to measure at home and when to see a doctor.
8 min read
Guides
Everything explained, with numbers.
15 guides across five pillars. Each one answers its question in the first paragraph, gives figures you can use and names its sources. Where a tool on this site fits the topic, the guide points to it.
Health 6 guides
Numbers you can measure at home, and what they mean
Health
Health
How many steps a day: what the studies support
A review of 57 studies puts the benefit near 7,000 steps a day, with 6,000 to 8,000 enough after 60. What was measured, and why 10,000 is not a thresh
8 min read
Health
How much sleep adults really need: 7 to 9 hours, and why
Most adults need 7 to 9 hours of sleep a night. What the NHS, a panel of 15 sleep scientists and a study of 1.38 million people say, and how to find y
8 min read
Health
Resting heart rate: what the number says
A normal resting heart rate is 60 to 100 beats a minute, yet the risk curve starts well below 100. How to measure it, what moves it and when to see a
7 min read
Health
Sitting: how much is too much
Measured sitting beyond about 9.5 hours a day goes with higher mortality unless you move 22 to 40 minutes a day. The cohort numbers and how to break i
8 min read
Health
Strength training after 40: how much is enough
Strength work on 2 or more days a week from 40, 3 from 65, says WHO. What muscle loses per decade, what 30 to 60 minutes a week is linked to, how to s
8 min readFood 2 guides
Plates, portions and the evidence behind them
Food
30 grams of fibre a day: where the number comes from
UK guidance says 30 g of fibre a day, WHO at least 25 g, and most adults manage about 20 g. Where the numbers come from and what a 30 g day looks like
9 min read
Food
The Mediterranean diet: what the evidence says
One trial of 7,447 adults, 30 randomised trials and 25 years of follow-up: what the Mediterranean diet does for the heart, and where the evidence is t
8 min readLife 3 guides
Light, rhythm, habits and the people around you
Life
How long a habit takes to form: 66 days, not 21
The often quoted 21 days has no basis. In the key study of 96 volunteers, a new daily habit took a median of 66 days, with a range of 18 to 254 days.
8 min read
Life
Screens in the evening and sleep: what the studies found
Each hour on a screen in bed went with 24 minutes less sleep in a survey of 45,202 students. What the trials show, and how long before bed to stop.
8 min read
Life
Social connection and health: what the large studies show
Loneliness is linked to 871,000 deaths a year and 1 in 6 people worldwide feel lonely. What 148 studies, 2.2 million cohort participants and the WHO s
8 min readLongevity 4 guides
Healthy years, not just more years
Longevity
Grip strength: the ageing marker in your hand
Every 5 kg less grip strength went with 16 percent higher mortality in 139,691 adults. Normal values by age, the 27 and 16 kg cut-offs, and how to tes
9 min read
Longevity
Healthspan versus lifespan: the years that count
Life expectancy is 73.1 years worldwide, healthy life expectancy only 63.5. What the 9.6 year gap means, why it is widest in rich countries, what narr
8 min read
Longevity
VO2 max: the fitness number that predicts survival
In 122,007 adults, low VO2 max predicted death more strongly than smoking or diabetes. What a good value is at your age and how far training moves it.
8 min read
Longevity
What the longest-lived regions have in common
Five regions, 9 shared habits and one hard question: what the Blue Zones data really show, and what 123,219 adults say about copying the habits at hom
8 min read