"Circadian rhythms regulate our biological cycles for sleep, activity level, metabolism, and many other processes through our body's exposure to sunlight and darkness," said Boris I. Medarov, MD, FCCP, Long Island Jewish Medical Center, New Hyde Park, NY. "Our study finds that lung function has its own rhythm that may govern how much energy we exert throughout the day and the best times to engage in certain activities."
The study investigated how lung function fluctuated throughout the working hours of 8:00 am and 5:00 pm. In a 5-year period, 4,835 patients underwent several breathing tests and were subdivided into nine groups based on the time of day the test was performed. Results of FEV1/FVC and total lung capacity testing were compared within nine time intervals. Results showed that patients' overall airway resistance was at its most prominent around 12:00 pm but reached its minimum between 4:00 to 5:00 pm, showing that lung function was at its best in the late afternoon.
"We often associate the end of the work day with being tired and less motivated for physical exertion; however, lung function seems to be at its best during this time. As a result, exercising or engaging in other physical activities in the late afternoon may help us to achieve optimal performance," said Dr. Medarov. Circadian rhythms of lung function may also have implications for the administration o
Contact: Jennifer Stawarz
American College of Chest Physicians