Athletes on the Sunshine Coast can volunteer for cardiac study to find the best time of day for vigorous exercise
(By news desk)
Vancouver kinesiologist Eleanor Roberts is constantly moving. She teaches soccer and yoga, and cycles to work, and seems an unlikely candidate for a heart attack. Yet Roberts is part of a study linking the heart and exercise, calling it “an opportunity to manage something I cannot see.”
Researchers from Vancouver Coastal Health (VCH), the University of British Columbia (UBC), and SportsCardiologyBC are in the final phase of recruiting for a study that will follow 126 recreational and competitive athletes for 10 years. The Time of Day Study will determine the safest time of day to exercise based on the presence of arrhythmia — or irregular heartbeats — during exercise.
“There is no disputing the tremendous benefits of exercise,” says Dr. James McKinney, the study’s lead author and cardiologist. “But we want to find out if there is a time of day when moderate to vigorous exercise is safest from a cardiac standpoint.”
The biological process responsible for our physical, mental and behavioral changes in a 24-hour period is known as circadian rhythm. External factors like sunlight and temperature affect our circadian rhythms, and research suggests that sudden cardiac death may also be linked to circadian rhythm. A study of more than 2,000 people in Massachusetts who died of sudden cardiac arrest found the patients’ circadian rhythms were more varied in the morning.
“There is a body of research that shows a higher rate of sudden cardiac death in the general population in the early morning,” says Dr. Saul Isserow, cardiologist and founder of SportsCardiologyBC. “We want to find out in our study whether the circadian rhythms of healthy people who exercise at moderate to high intensity at certain times of the day have any influence on myocardial infarction [heart attack] and sudden cardiac death. In a nutshell, we’re looking at whether the risk of a cardiac event — albeit already very low because the people in the study exercise — is greater in the morning or the evening.”
The study is open to competitive and recreational athletes over the age of 18 who engage in four hours of endurance exercise per week and are able to reach a target heart rate of 60 to 70 per cent. Participants fill out a questionnaire and undergo an electrocardiogram (ECG) and stress test. The participants are then outfitted with a Holter monitor to record their heartbeat for 24 hours and exercise with it in the morning and the evening so the results can be compared. They will be retested after the first year, then again in five and 10 years.
“Being part of this study gives me a sense of comfort,” says Roberts. “I would probably never undergo cardiac screening, so I see this as an opportunity to evaluate myself as an athlete and get a head-start on my heart health.”
SportsCardiologyBC is a non-profit organization dedicated to making sports safer for athletes through research and education. The SportCardiologyBC clinic at UBC Hospital plays a leading role in sports cardiology research.
The study is still recruiting, and interested participants can contact SportsCardiologyBC at http://www.sportscardiologybc.org/research/