Studies

An American study in collaboration with Apple confirms: more light = less stress

About study

✓ Overall health

Title:

Summer Glow: How much daylight are Apple Heart and Movement Study participants getting and why does it matter?

Author: Calum MacRae, Angela Spillane, Courtney Smith, James Truslow, Diana Nascimben, Kat Cyr, Huiming Lin, Shinichi Goto, Fanual Berhe, Hannah Keough
Date: 20. October 2025
Source: https://appleheartandmovementstudy.bwh.harvard.edu/summer-daylight-2024/

Brief summary

The Summer Glow study, conducted in the USA as part of the Apple Heart and Movement Study, focuses on the importance of light for mental and physical health and vitality. It uses measurement via the Time in Daylight feature in Apple Watch, which records the time spent in natural daylight. The study reveals how our exposure to daylight changes throughout the year and what impact it has on our health and lives.

Seasons significantly affect how much time we spend in daylight

The analysis included 58,350 participants from the USA, who together provided more than 9.6 million days of records. The results show significant seasonal differences: while in January participants spent an average of 30.8 minutes outdoors per day, in June the average increased to as much as 102.1 minutes.

Daylight affects stress levels

An important part of the analysis was the relationship between the amount of daylight and the level of subjectively perceived stress. Participants who, on average, spent more than 90 minutes per day in the light showed a 22.8% lower likelihood of high stress than those who spent less than 40 minutes outdoors. This result confirms existing scientific findings about the positive effects of natural light on mental health and overall psychological well-being.

Light has an impact on our health

The study thus offers a new, strongly data-supported perspective on everyday exposure to light and its connection to health. It points out that even a relatively small increase in time spent in natural light can have beneficial effects on both physical and mental health and overall vitality.

PF2026

To create an account, please contact us: info@spectrasol.cz

If the prices do not appear after successful login, refresh the page by pressing F5.

Are you interested in the products? More details?
Or do you just want to talk?

Do you prefer to email or call?

info@spectrasol.cz
+420 776 293 925

Max. file size: 10 MB.
Souhlas(Required)