Recent studies reveal that long-term, high-duration endurance exercise is associated with increased arterial plaque, including dangerous types. However, this does not necessarily translate to higher cardiovascular mortality. The relationship between exercise and heart health is nuanced, with light to moderate exercise remaining beneficial, while the effects of very high volumes of exercise require further investigation.
It may sound counterintuitive, but recent research shows that more exercise, especially long-term endurance exercise, can be associated with increased arterial plaque. This finding comes from multiple studies and challenges some common assumptions about exercise and cardiovascular health. However, the story is nuanced and does not suggest that exercise is bad for you. This article explores the data, the types of plaque involved, and what it means for your heart health.
One study examined the prevalence of arterial plaque in three groups:
Shockingly, the group with the longest duration of exercise had more arterial plaque than the others. This was not just any plaque but included a higher amount of the most dangerous types: mixed and non-calcified plaque. These types are more likely to rupture and cause serious cardiovascular events.
Importantly, these findings were observed in individuals with no previous history of cardiovascular disease and who were leaner than the control group.
There are three distinct types of arterial plaque:
Calcified plaque is considered the least dangerous, while mixed and non-calcified plaques are more prone to rupture and cause heart attacks or strokes.
A follow-up study investigated whether the increased plaque was related to the duration or intensity of exercise. The data showed:
This suggests that the total time spent exercising, rather than how hard one exercises, is linked to the increased plaque.
Intuitively, more plaque should mean higher risk of heart attacks, strokes, and death. However, studies focusing on very physically fit individuals have not found a direct relationship between increased physical activity, more plaque, and cardiovascular mortality.
These studies primarily looked at calcified plaque, which is less dangerous. Therefore, while more physically active people may have more calcified plaque, this does not necessarily increase their risk of cardiovascular death.
Many studies rely on self-reported exercise data, which can be inaccurate. The studies showing a relationship between exercise duration and plaque used objective data from wearable devices, providing more reliable results.
When comparing self-reported data to device-measured data, the trends differed significantly, highlighting the importance of precise measurement techniques.
Several factors influence the interpretation of these findings:
Nutrition: None of the studies accounted for nutrition, but since the plaque relationship was constrained to exercise, nutrition differences are unlikely to explain the findings.
Control Group Activity: The control group was not sedentary but lightly active, which affects how we interpret the differences.
Outcome Data: No studies have measured cardiovascular events or death in people who have exercised their entire lives, especially concerning soft plaque.
Stenosis: Studies measuring artery narrowing (stenosis) found concerning levels of blockage (>50%) in some highly active individuals.
The key takeaway is that exercise remains beneficial for heart health, but the amount of exercise may need reconsideration. Light to moderate endurance exercise (up to about three hours per week) appears low risk and likely beneficial over a lifetime.
High-volume endurance exercise (around 10 hours per week or more) is associated with increased arterial plaque, but it is unclear if this translates to higher cardiovascular risk.
If you jog a few days a week, these findings likely do not apply to you. However, if you participate in marathons, triathlons, or have been a heavy endurance exerciser your entire life, this information is more relevant.
Importantly, these findings do not apply to resistance training.
Some studies indicate that exercise can reverse plaque, adding complexity to the relationship between exercise and arterial health. This does not contradict the findings discussed but suggests that the effects of exercise on plaque are multifaceted.
Exercise is good for you, but more is not always better. The relationship between exercise duration and arterial plaque is complex and requires further research, especially regarding long-term cardiovascular outcomes.
For now, moderate endurance exercise remains a safe and beneficial recommendation. Those engaging in very high volumes of endurance exercise should be aware of the potential for increased arterial plaque and consider discussing their exercise habits with healthcare professionals.
Stay informed, and remember that exercise is a powerful tool for health when done thoughtfully.
Thank you for reading, and stay tuned for more insights on health and exercise.
