The 11-minute rule, re-read
The internet's favourite cold and heat dose came from a description of what one group of swimmers did. What the study actually showed.
The Research
Read the studies, not the hype.
Every piece here starts with a paper, names it, and says what it does and does not show. Written for people over forty who want the evidence before the equipment.
Before the clocks change: the 90-minute warm water rule
Daylight saving starts on Sunday. Warm water timed well before bed is one of the best-supported sleep habits there is.
Keep the muscle: when not to plunge
Muscle is a longevity asset after 50. Cold straight after lifting may take a little of the gain. How to time it.
Adelaide researchers pooled the cold plunge evidence. Here is what held up.
A University of South Australia review brought together 11 studies on cold water immersion. What worked, what did not, and what we still do not know.
World Heart Day: the Finnish heart data in plain numbers
The cornerstone sauna study, explained properly: who was studied, what they used, what the results mean and what they cannot tell you.
What your heart does in 7 °C water
New ECG data from middle-aged cold water swimmers in Geneva. A calm read for anyone over 45 considering an ice bath.
Women, sauna and sleep
Most sauna data comes from Finnish men. A 2026 Swedish study looked at what women and men report after bathing.
Who should not use a sauna, and how older adults use one well
The safety question, answered first. Who should avoid sauna, what raises risk, and simple habits for bathing well after 50.
A longevity week for over-50s: heat, cold, light and movement
The capstone of our 30-day series. One practical week built only from the research we have covered.
More light is not more benefit
Red light follows a dose curve, and too much can undo the effect. Why the Red Light Bed has a lower-power residential mode.
Heat and mood: what the UCSF trials actually tested
For World Mental Health Day. The research on heat and depression is promising and often misquoted. Here is what was actually done.
Collagen, measured: the full-body red light trial
The most cited red light skin trial used full-body devices and measured collagen with ultrasound. What it found.