In the JournalsPerspective

Running and the heart: Multiple marathons do not raise atherosclerosis risk

A new study suggests that healthy, middle-aged men who participate in intensive endurance exercise such as running multiple marathon races do not have an increased risk for premature subclinical atherosclerosis.

“Our study shows that runners who have finished 20 marathons do not have stiffer arteries or more impaired vessel function than people of the same age who have finished five or zero marathons. We can conclude that marathon running itself is not a risk factor for atherosclerosis,” Axel Pressler, MD, head of the prevention center at Technical University in Munich, said in a press release.

Pressler and colleagues reviewed data on 97 men who previously ran marathons and were participating in the Munich marathon. The official distance of a marathon race is 26.2 miles.

The men studied did not have a history of CVD or regular medication use at baseline. Eighteen participants had a positive family history for CVD, and all runners were nonsmokers. The researchers reported extensive clinical assessment, including cardiopulmonary exercise testing, carotid ultrasound and ECG before the marathon race. Participants also provided information on their marathon preparation and number of completed marathons.

Before the Munich marathon, participants previously completed a median of eight half marathons (distance, 13.1 miles; n = 67), six full marathons (n = 87) and three ultramarathons (n = 14). An ultramarathon is any distance longer than 26.2 miles.

Runners trained an average of 59 km per week (approximately 36.6 miles) and a mean running distance of 1,639 km (approximately, 1,018 miles) per year.

The runners’ mean time for completing the Munich marathon was 3 hours, 45 minutes.

Mean peak oxygen uptake was 50.3 mL/kg per minute.

The researchers reported “normal mean values” for ankle-brachial index (1.21 ± 0.1), intima-media thickness (0.6 ± 0.14 mm), pulse wave velocity (8.7 ± 1.4 m per second), augmentation index (17 ± 12.7%) and reactive hyperemia index (1.96 ± 0.5) for the runners.

The mean age of runners in this study was 44 years (range, 22-64).

“Significant associations were found for age only, with a higher prevalence of abnormal values for intima-media thickness, augmentation index and pulse wave velocity in older runners, independent of exercise-related parameters. These findings indicate that repeated exposition to strenuous exercise does not seem to pose an independent risk factor for premature vascular impairment beyond the influence of age,” Pressler and colleagues wrote in the European Journal of Preventive Cardiology.

Key vascular parameters were not difference between participants who completed at least one ultramarathon compared with those who only completed half or full marathons before the Munich marathon, according to the findings.

“In this cohort of healthy, middle-aged male runners, no significant impact of exercise history, training history, number of previously completed half, full or ultramarathon races or marathon finishing time on markers of subclinical vascular impairment was observed. ... Our findings ... are in line with the majority of previous observations in not supporting an independent detrimental effect of (ultra)marathon running on vessel integrity. It should, however, be noted that repeated marathon running does also not appear to introduce beneficial effects on subclinical vascular structure and function,” the researchers concluded. – by Darlene Dobkowski

Disclosures: The main EnzyMagic trial was funded by Mucos Pharma. The researchers report no relevant financial disclosures.

A new study suggests that healthy, middle-aged men who participate in intensive endurance exercise such as running multiple marathon races do not have an increased risk for premature subclinical atherosclerosis.

“Our study shows that runners who have finished 20 marathons do not have stiffer arteries or more impaired vessel function than people of the same age who have finished five or zero marathons. We can conclude that marathon running itself is not a risk factor for atherosclerosis,” Axel Pressler, MD, head of the prevention center at Technical University in Munich, said in a press release.

Pressler and colleagues reviewed data on 97 men who previously ran marathons and were participating in the Munich marathon. The official distance of a marathon race is 26.2 miles.

The men studied did not have a history of CVD or regular medication use at baseline. Eighteen participants had a positive family history for CVD, and all runners were nonsmokers. The researchers reported extensive clinical assessment, including cardiopulmonary exercise testing, carotid ultrasound and ECG before the marathon race. Participants also provided information on their marathon preparation and number of completed marathons.

Before the Munich marathon, participants previously completed a median of eight half marathons (distance, 13.1 miles; n = 67), six full marathons (n = 87) and three ultramarathons (n = 14). An ultramarathon is any distance longer than 26.2 miles.

Runners trained an average of 59 km per week (approximately 36.6 miles) and a mean running distance of 1,639 km (approximately, 1,018 miles) per year.

The runners’ mean time for completing the Munich marathon was 3 hours, 45 minutes.

Mean peak oxygen uptake was 50.3 mL/kg per minute.

The researchers reported “normal mean values” for ankle-brachial index (1.21 ± 0.1), intima-media thickness (0.6 ± 0.14 mm), pulse wave velocity (8.7 ± 1.4 m per second), augmentation index (17 ± 12.7%) and reactive hyperemia index (1.96 ± 0.5) for the runners.

The mean age of runners in this study was 44 years (range, 22-64).

“Significant associations were found for age only, with a higher prevalence of abnormal values for intima-media thickness, augmentation index and pulse wave velocity in older runners, independent of exercise-related parameters. These findings indicate that repeated exposition to strenuous exercise does not seem to pose an independent risk factor for premature vascular impairment beyond the influence of age,” Pressler and colleagues wrote in the European Journal of Preventive Cardiology.

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Key vascular parameters were not difference between participants who completed at least one ultramarathon compared with those who only completed half or full marathons before the Munich marathon, according to the findings.

“In this cohort of healthy, middle-aged male runners, no significant impact of exercise history, training history, number of previously completed half, full or ultramarathon races or marathon finishing time on markers of subclinical vascular impairment was observed. ... Our findings ... are in line with the majority of previous observations in not supporting an independent detrimental effect of (ultra)marathon running on vessel integrity. It should, however, be noted that repeated marathon running does also not appear to introduce beneficial effects on subclinical vascular structure and function,” the researchers concluded. – by Darlene Dobkowski

Disclosures: The main EnzyMagic trial was funded by Mucos Pharma. The researchers report no relevant financial disclosures.

    Perspective
    John P. Higgins

    John P. Higgins

    Some prior studies have suggested that too much running can have a negative effect on the CV system overall. This study, which tracked almost 100 male runners who had completed several marathons or ultramarathons and who were running on average 37 miles per week — just over 5 miles a day — did not find this at all. Using various tests of vascular function, including arterial ultrasound, they noted no significant adverse effect of endurance running. The only correlation was worsening of vascular function with age.

    With respect to the idea of a “J-curve” for running (eg, too little or too much running is bad for your vascular function), this study did not find that excess running is bad for vascular function.

    Clinicians can tell their patients who are runners, especially those who like to do longer distance runs, that these long runs are not going to negatively impact their vascular function or CV system. Indeed, many benefits with regard to a reduction in CV risk factors (eg, hypertension, hyperlipidemia, insulin resistance/diabetes, obesity and smoking) are associated with running, and going longer is likely more beneficial.

    For people who are walking for health and cannot run such as the elderly, it is important to get a moderate amount of exercise each day. Recent studies suggest at least 10,000 steps per day to maintain health, and 15,000 steps per day to significantly improve vascular function.

    It’d be interesting to see research on the optimal amount of exercise per day to most benefit CV function, as well as what exercise combination is best, for example, 4 days of aerobic exercise and 3 days of resistance/balance/flexibility vs. other methods. Further research is needed on biomarkers vs. various exercises, including whether troponin I elevation occurs more with endurance running, bicycling or swimming vs. long sessions of high-intensity interval training or resistance training. It would also be helpful to know what level of chronic exercise will improve vascular function. For example, is 150 minutes per week of moderate-intensity exercise adequate?

    This paper did not include women.  More research is needed on them. Also, there is no evidence that endurance running is associated with premature osteoarthritis — in fact, there is a significant reduction in osteoarthritis in exercises shown in excellent MRI cohort studies.

    There may be a slight increase in atrial fibrillation with endurance running. This needs to be confirmed in larger and well-controlled cohort studies.

    • John P. Higgins, MD, MBA
    • Sports Cardiologist McGovern Medical School University of Texas Health Science Center

    Disclosures: Higgins reports no relevant financial disclosures.