Graham Beaton BHSc, ND
Doctor of Naturopathic Medicine

An interesting article was recently published on PLoS ONE (Public Library of Science) on adverse changes to cardiovascular risk markers (plasma HDL-C, triglycerides, fasting insulin and resting systolic blood pressure) with regular exercise. The authors found that across several studies (e.g. HERITAGE Family Study, DREW, INFLAME, STRRIDE, University of Maryland Gene Exercise Research Study, and University of Jyvaskyla Study) some participants had adverse cardiovascular risk factor responses to regular exercise.

While previous research has consistently shown that exercise lowers triglycerides (a type of fat found in circulation), systolic blood pressure, fasting insulin and raises HDL-C (good cholesterol), new evidence suggests that the healthy benefits of exercise are not seen in all individuals. In some people, the opposite happens – and this effect has been seen regardless of the intensity of exercise. In addition, about 7% of participants in the studies reviewed also experienced an adverse response in two or more risk factors.

It is not currently known why exercise has a negative influence on some of the participants, but a genetic predisposition might be the cause. Currently it is also unclear what effect, if any, these adverse responses have on health outcome (heart attack, stroke) as the studies only looked at risk factors at a specific moment in time (i.e. they did not follow participants over a long period of time).

While this study did show unexpected cardiovascular responses in certain individuals, it reinforces the importance of monitoring risk factors, especially when starting a new exercise plan.

Keep in mind, exercise is still safe and healthy – and these new findings should not be
used as an excuse to avoid starting or maintaining an exercise program. They are just a reminder that all interventions have possible side effects, and a reminder to get cardiovascular risk factors screened regularly.

Graham Beaton is a Naturopathic Doctor practicing in the Golden Triangle neighborhood of downtown Ottawa. If you have questions on heart health, how Naturopathic Medicine can help you or on another health concern, give him a call at 613-290-6115.