Improving aerobic capacity decreases the risk of cardiovascular disease (CVD), according to a workshop conducted at the Singapore Prevention & Cardiac Rehabilitation Symposium 2017.

Improved aerobic capacity results in the downregulation of sympathetic activity characterized by decreased heart rate, breathing or ventilation, blood pressure, and rate of perceived exertion, said Prof John Buckley, professor of Applied Exercise Science in Health at the University Centre Shrewsbury in Shropshire, UK.

Improved aerobic capacity may be manifested by increased endurance, maximum volume of oxygen (VO₂ max), or VO₂ fuel efficiency, said Buckley, highlighting the significance of the latter.

Better fuel efficiency enables better performance, as demonstrated in a previous study comparing East African and European middle-distance runners. [Sports Med 2007;37:316-319] “The East African runners used much less oxygen, which is why they can run faster,” said Buckley. “[I]f you are more fuel efficient, you produce less heat [and carbon dioxide] … Your own carbon footprint is reduced by being fitter.”

[ Prof John Buckley ]

An individual with an exercise capacity of <5 metabolic equivalents (METs) has a higher risk of dying prematurely compared with someone with an exercise capacity of 11 METs, [JAMA 1989;262:2395-2401; NEJM 2002;346:793] hence the importance of improving aerobic capacity as it is a powerful predictor of mortality and an independent risk factor for CVD. “Cardiac disease makes people less fuel efficient so patients tend to use more oxygen [though] they have less capacity,” said Buckley.

Once an aerobic capacity of >7 METs is achieved and overall fitness is improved, the overall risk of cardiovascular morbidity and mortality is eventually reduced, he continued. “Reducing sedentary time … even getting people to be on their feet a little bit more [often] is going to be beneficial.”

Nonetheless, Buckley pointed out that despite the significant benefits of a regular exercise programme on aerobic capacity, individuals usually lean towards “losing weight and looking beautiful”. “They don’t think about anything else … and they assume that the two are linked together,” he continued.

If these expectations are not met, the eagerness to exercise regularly drops as individuals fail to realize the more important benefits gained from regular exercise such as improved aerobic capacity even if the scales do not reflect a major weight change, said Buckley.

Therefore, it is essential for clinicians to reiterate the importance of maintaining a regular exercise programme to their patients in order to improve aerobic capacity and optimize fuel efficiency that will be key to reducing CVD risks, noted Buckley.