longevity
How to live longer, ranked by how much the evidence actually supports each lever: cardiorespiratory fitness first, then strength, sleep regularity and social connection.
6 briefings
How often should I lift weights: meta-analyses put the sweet spot at 30 to 60 minutes of resistance training a week. Past about 130 minutes the survival curve flattens and may reverse.
What is a good VO2 max depends on age and sex, but the direction matters more: in a 122,000-person cohort, the gap between low and elite fitness carried a larger hazard than smoking, diabetes or heart disease.
A VO2 max chart shows normative ranges by age and sex. What matters more is which direction yours is moving, because cardiorespiratory fitness responds to training at any age.
Fasting for blood work is still required for glucose, insulin and some metabolic panels, but increasingly not for lipids. Here is what to fast for, and for how long.
A DEXA scan body fat percentage is the practical reference standard, accurate to within about 1 to 3%. Consistency of scan conditions matters more than which scanner you use.
Age-related muscle wasting costs adults 3 to 8% of muscle mass per decade after 30, accelerating after 60. Protein and resistance training are the only two levers that reliably slow it.
