Summary: Being an “early bird” and maintaining a physically active lifestyle may significantly reduce the risk of developing amyotrophic lateral sclerosis (ALS). A preliminary study involving over 500,000 participants found that those with a morning chronotype had a 20% lower risk of ALS compared to “night owls.”
Additionally, participants who engaged in regular physical activity saw a 26% reduction in risk. While the study shows an association rather than direct cause-and-effect, it suggests that aligning sleep schedules with daylight and staying active could be a potential strategy for preventing this progressive neurodegenerative disease.
Key Facts
- The Early Bird Advantage: People who preferred earlier bedtimes and wake times (morning chronotype) had a 20% lower risk of ALS than those who preferred later hours.
- Activity is Key: Engaging in 600 MET-minutes or more of physical activity per week (roughly equivalent to 150 minutes of brisk walking) was associated with a 26% lower risk.
- Optimal Sleep Duration: Participants who slept between six and eight hours per night had a lower risk of ALS compared to those who slept more or less.
- Large-Scale Data: The study followed half a million people for an average of 14 years, during which 675 participants developed ALS.
- Circadian Alignment: Researchers believe that a sleep schedule that better matches natural daylight hours may play a role in neuroprotection.
Source: AAN
Being an early bird, also called a morning person, and being more physically active are associated with lower risks of amyotrophic lateral sclerosis (ALS), according to a preliminary study released February 25, 2026, that will be presented at the American Academy of Neurology’s 78th Annual Meeting taking place April 18-22, 2026, in Chicago and online.
The study does not prove cause and effect between these behaviors and the risk of ALS; it only shows an association.
ALS is a rare, progressive disease characterized by the degeneration of nerve cells in the brain and the spinal cord. People with ALS lose the ability to initiate and control muscle movement, which often leads to total paralysis and death. The average life span after diagnosis is two to five years.
“Previous research suggests better sleep and more physical activity may reduce the risk of some neurodegenerative diseases, but results for ALS have been mixed,” said study author Hongfu Li, MD, PhD, of Zhejiang University in Hangzhou, China. “Our study found a sleep schedule that better matches daylight hours and more physical activity were related to a lower risk of ALS.”
The study included over 500,000 people with an average age of 57. Participants were followed for an average of 14 years, during which 675 people, or 0.14%, developed ALS.
Participants completed questionnaires at the start of the study about their sleep habits and physical activity.
For sleep, researchers determined chronotypes for all participants. Chronotype is a person’s natural preference for when they are most alert and most sleepy. It is part of the circadian rhythm, the 24-hour sleep-wake cycle.
Researchers looked at two chronotypes. Morning chronotype, or early birds, was defined as people who preferred earlier bedtimes and wake times and reported peak productivity earlier in the day. Evening chronotype, or night owls, was defined as people who preferred later bedtimes and wake times and reported peak productivity later in the day.
Of participants, 277,620 were classified as early birds and 166,361 as night owls. Of early birds, 350 developed ALS. Of night owls, 237 developed ALS. Another 58,298 were excluded because their chronotype could not be determined.
After adjusting for factors such as age, sex and body mass index, researchers found being an early bird was associated with a 20% reduced risk of ALS compared to being a night owl.
Researchers also looked at sleep duration and found those who had between six and eight hours of sleep per night had a lower risk of ALS compared to those who had more or less sleep.
Researchers also found that greater physical activity was associated with a 26% lower risk of ALS.
They used metabolic equivalents (METs) to quantify energy expenditure. For each physical activity, METs were multiplied by the frequency and duration to obtain a physical activity score of MET-minutes per week. Vigorous activities such as running and cycling were assigned 8.0 METs, moderate-intensity activities like carrying light loads and household activities were assigned 4.0 METs, and lower-intensity activities such as walking were assigned 3.3 METs. The average physical activity level for participants was 2,645 METs-minutes per week.
Researchers found that among those who had more physical activity, 600 MET-minutes or more per week, 386 of 314,170 people developed ALS. Among those who had less, 107 of 70,946 people developed ALS.
After similar adjustments, 600 MET-minutes or more per week was associated with a 26% lower risk of ALS.
“While more research is needed to further explore these associations, promoting healthy lifestyle behaviors may represent a potential strategy for reducing the risk of ALS,” said Li.
A limitation of the study was that 95% of participants were white people, so the results may not be the same for other populations.
Funding: The study was funded by the Chinese national level major research program.
Key Questions Answered:
A: No, the study does not prove that staying up late causes ALS. It simply shows an association between sleep timing and disease risk. Many factors, including genetics and environment, contribute to ALS, but this research suggests that circadian alignment might be one piece of the puzzle.
A: The study found benefits at 600 MET-minutes per week. In practical terms, this is about 2.5 hours of moderate activity, like brisk walking or light household chores, or about 75 minutes of vigorous activity like cycling or running, spread throughout the week.
A: Both appear important. The research found that the “sweet spot” for sleep is between six and eight hours. Sleeping significantly more or significantly less than that was linked to a higher risk, independent of whether you are an early bird or a night owl.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by our staff.
About this ALS research news
Author: Renee Tessman
Source: AAN
Contact: Renee Tessman – AAN
Image: The image is credited to Neuroscience News
Original Research: The findings will be presented at the American Academy of Neurology’s 78th Annual Meeting
