Aging: Exercise timing, consistency can affect heart and lung fitness

Medical News Today

27-05-2025

Written by Corrie Pelc on May 27, 2025 — Fact checked by Amanda Ward
Exercise timing and consistency can influence heart and lung fitness as we age. Image credit: Alina Rudya/. Researchers have come to have a better understanding of how the body's circadian rhythm impacts their overall health.
Past studies show that disrupting the natural sleep/wake cycle can increase a person's risk for several health conditions.
The circadian rhythm also defines the times a person performs activities during the day, such as when they exercise.
A new study says that people who work out at the same time every day may improve their cardiovascular and lung health as they age.
Over the past few years, researchers have come to have a better understanding of how the body's circadian rhythm impacts overall health.
In addition to regulating when you are awake or sleeping, the circadian rhythm also defines the times you perform activities during the day such as when you go to work, when you eat different meals, and when you exercise.
Now, a new study published in the journal Medicine & Science in Sports and Exercise reports that people who work out at the same time every day may improve their cardiovascular and lung health as they age.
For this study, researchers recruited about 800 older adults with an average age of 76 years. Study participants were asked to wear wrist-worn accelerometers for seven days to measure their daily activity, and also underwent cardiopulmonary exercise testing to assess their heart and lung health.
'Cardiorespiratory fitness is a measure of how well your heart, lungs, and muscles work together in response to exercise,' Karyn Esser, PhD, professor and chair of the Department of Physiology and Aging in the College of Medicine at the University of Florida, senior author of this study, told Medical News Today .
'Higher values are strongly associated with longer lifespan and lower mortality risks,' Esser explained.
The study also evaluated the walking efficiency of participants, which is considered another indicator of healthy aging.
'Walking efficiency provides an assessment of how efficiently the body uses energy to walk forward,' Esser noted. 'The more efficient you are, the farther you can walk. It's another measure of fitness.'
At the study's conclusion, Esser and her team found that participants who had the most activity during the active part of their day relative to their daily resting time, and whose maximum daily activity happened earlier in the day, were correlated to better cardiorespiratory fitness and walking efficiency.
'We found that earlier peak activity was associated with better outcomes even when you [take] into account the amount of activity,' the researcher detailed. 'This suggests that getting moving earlier in the day could provide a health benefit. In addition, we found that the amplitude of the activity, or amount of activity during the day was healthy, this is maybe not such a surprise.'
Additionally, scientists observed that better health outcomes were correlated to having a greater consistency in daily activity patterns, with the highest activity time happening at the same time every day.
'This was an interesting finding as, again, we took into account the amount of activity so this is saying that being consistent with your activity pattern is an additional parameter of your activity that likely contributes to healthy outcomes,' Esser said.
To sum up, Esser said that this study finds that maintaining a daily programme of activity that includes attention to the timing and consistency of activity is important for maintaining health as we age.
'While we are living longer, in general, we are not living healthier,' she explained. 'So it is important to find ways to help people maintain or improve their health while aging, [to] improve quality of life and diminish the impact of age-related chronic diseases.'
'We suggest that the earlier time of activity and repeatability of the activity provide benefits in addition to just the activity alone,' Esser continued. 'Lastly, we propose that the timing and reproducibility of the activity are working with our intrinsic circadian clock system to maintain health.'
'We are continuing to expand our clinical study of circadian, or time of day activity behavior, with other outcomes including sleep, pain, cognition, and mental health,' she added. 'In addition, my lab has ongoing preclinical studies to determine more mechanistically how the timing of activity impacts health with aging.'
MNT had the opportunity to speak with Cheng-Han Chen, MD, a board certified interventional cardiologist and medical director of the Structural Heart Program at MemorialCare Saddleback Medical Center in Laguna Hills, CA, about this study.
'This study found an association between the timing of daily physical activity and measures of cardiopulmonary fitness,' Chen commented. 'This suggests that we may eventually be able to better tailor our exercise recommendations in order to optimize the physiological benefits.'
'Getting regular exercise is an essential part of staying healthy as you get older. As our population ages, strategies to improve physical fitness may help us reduce the burden of disease in our society. More research will be needed to determine whether intentionally changing and optimizing the rhythm of daily physical activity will lead to better health outcomes.'
– Cheng-Han Chen, MD
Heart Disease
Seniors / Aging
Sports Medicine / Fitness