Consistently Exercising at Same Time May Boost Heart and Lung Health Through Circadian Rhythm Alignment: Study
USA: It is established that disruptions to circadian rhythm are linked to increased risks for conditions like heart disease, type 2 diabetes, obesity, depression, and certain cancers. Beyond regulating sleep, circadian rhythm also governs daily activities, including exercise timing.
Now, a new study published in Medicine & Science in Sports & Exercise suggests that older adults who maintain consistent patterns of activity—particularly exercising around the same time each day—may significantly enhance cardiovascular and lung health. The research, led by Dr. Karyn A. Esser from the Department of Physiology and Aging at the University of Florida College of Medicine, provides new insights into how the body’s internal clock influences physical performance in aging populations.
The study analyzed data from 799 older adults enrolled in the Study of Muscle, Mobility, and Aging. The average age of participants was 76 years, and 58% were women. Researchers used wrist-worn accelerometers to continuously monitor participants’ rest-activity cycles. From this data, they derived several measures of rhythmic behavior, such as amplitude (a measure of the strength of the activity rhythm), robustness (regularity of the rhythm), and acrophase (time of peak daily activity).
By linking these circadian-related metrics with physiological outcomes, the team examined how patterns of daily movement correlated with cardiorespiratory fitness, measured by VO2 peak, and walking energetics, reflected in the cost-capacity ratio at both slow and preferred walking speeds.
The study revealed the following findings:
- Individuals with more rhythmic daily activity patterns demonstrated better physical health indicators.
- Participants with the highest amplitude of activity rhythm had a higher VO2 peak (22.0 mL·kg⁻¹·min⁻¹) compared to those with the lowest amplitude (18.4 mL·kg⁻¹·min⁻¹).
- Greater rhythm robustness was associated with higher cardiorespiratory fitness.
- An earlier time of peak daily activity was linked to improved VO2 peak levels.
- Stronger and more consistent activity rhythms correlated with improved walking energetics.
- Participants with more rhythmic activity patterns had a lower cost-capacity ratio, indicating more efficient energy use during walking.
- These associations were statistically significant across amplitude, robustness, and timing of peak activity.
The authors suggest that maintaining a regular activity schedule that aligns with natural circadian rhythms may play a crucial role in promoting physical resilience as we age. “These results support the concept that reinforcing daily rhythmic activity can positively impact physiological health,” they noted.
While the study focused on observational data, it highlights the need for further research to explore whether interventions aimed at improving circadian rhythmicity could help prevent age-related decline or disease onset. The researchers advocate for longitudinal studies to assess whether disruptions in daily activity patterns might serve as early indicators of declining health in older adults.
Reference:
Erickson, Melissa L. PhD1; Blackwell, Terri L.2; Garcia, Reagan E.4; Mau, Theresa2,3; Cawthon, Peggy M.2,3; Cummings, Steven R.2,3; Farsijani, Samaneh4; Sparks, Lauren M.1; Noone, John1,6; Glynn, Nancy W.4; Newman, Anne B.4; Esser, Karyn A.5. Rest Activity Rhythms and their Association with Cardiorespiratory Fitness and Walking Energetics in Older Adults: Study of Muscle, Mobility and Aging. Medicine & Science in Sports & Exercise ():10.1249/MSS.0000000000003730, April 18, 2025. | DOI: 10.1249/MSS.0000000000003730
