Tim Ferriss popularised the phrase but the concept predates him by decades. In pharmacology, the minimum effective dose (MED) is the smallest amount of a drug needed to produce the desired effect. Beyond the MED, more drug produces more side effects without more benefit.
The same principle applies to almost every health behaviour.
The MEDs That Surprise People
- Exercise: 2 × 45-minute resistance sessions per week captures most longevity benefit. You don't need to train like an athlete to live longer.
- Meditation: 10–13 minutes per day shows measurable cognitive and emotional benefits in controlled trials. Not an hour.
- Cold exposure: 2–3 minutes at 14°C produces the noradrenaline response. You don't need 20 minutes in an ice bath.
- Sunlight: 10–15 minutes of direct sun exposure at solar noon produces the circadian entrainment signal. More doesn't proportionally improve outcomes.
Why This Matters
Most people fail not because they do too little — but because they set maximalist targets, get overwhelmed, and do nothing. The MED approach removes the cognitive and physical barriers to starting.
Start with the minimum. Build from there.