Home ENGLISH MAGAZINE Low exercise is bad, that's given: is too much bad as well?

Low exercise is bad, that’s given: is too much bad as well?

Exercise is often cited as the best preventive medicine, but how much is too much for the hearts of middle-aged athletes? The real question has never been whether exercise is good for you, but whether extreme exercise is bad for you. For the past decade or so, there’s been increasing concern that high-volume, high-intensity exercise could injure the heart. Sports cardiologist Dr. Benjamin Levine led a study, now published in JAMA Cardiology, to find the answer. Dr. Levine is a Professor of Internal Medicine and Director of the Institute for Exercise and Environmental Medicine, a collaboration between UT Southwestern Medical Center and Texas Health Presbyterian Hospital Dallas. What is coronary calcium scanning and why is it important? Coronary calcium is a footprint of atherosclerosis, a disease in which plaque builds up in the arteries and gives rise to heart attack and stroke. When coronary calcium is detected in the heart, the clogging process within the blood vessels has begun. The majority of high-intensity athletes had low levels of coronary calcium, though their odds of having higher levels were 11% greater than men who exercised less. Most importantly, the researchers found that higher calcium scores did not raise the high-intensity athletes’ risk for cardiovascular or all-cause mortality.

Coronary calcium scanning is an imaging test that helps physicians classify patients without cardiac symptoms as low, intermediate, or high risk for heart attack. It represents how much calcium (and thus cholesterol deposits) has accumulated in the blood vessels that supply the heart. The scan can help physicians determine the need for medication, lifestyle modification, and other risk-reducing measures. Dr. Levine studied data from the Cooper Center Longitudinal Study. A total of 21,758 generally healthy men ages 40 to 80 and without cardiovascular disease were followed for mortality between 1998 and 2013. The athletes, a majority of them in middle age, reported their physical activity levels and underwent coronary calcium scanning. Most were predominantly runners, but some were cyclists, swimmers, or rowers. A subgroup of athletes trained in three of these sports. Women were not included in the study as their mortality rates are lower than for men. High-volume, high-intensity exercise was defined in this study as at least five to six hours per week at a pace of 10 minutes per mile. The average amount of high-intensity exercise in this group was eight hours per week. Despite the findings that extreme exercise does not raise heart disease risk, Dr. Levine advises against using the protective effect of exercise to excuse poor lifestyle habits.

He commented the results and the implications: “You cannot overcome a lifetime of bad behaviors – smoking, high cholesterol, hypertension – just from doing high levels of physical activity, so don’t use that as a magical cure. I recommends caution when starting a new training program. If you want to train for a marathon, you have to have a long-range plan to build up slowly before you achieve those volumes and intensity of exercise. We found that high volumes of exercise are safe, even when coronary calcium levels are high. The known benefits of regular physical activity in the general population include decreased mortality, heart disease, diabetes, and many other medical conditions which reminds us how important it is participate in regular physical activity as recommended by the 2018 Physical Activity Guidelines. The current study shows no increased risk of mortality in high-volume exercisers who have coronary artery calcium. Certainly, these high-volume exercisers should review their cardiovascular disease risk with their primary care doctor or cardiologists and the study results provide helpful clinical guidance. The most important take-home message for the exercising public is that high volumes of exercise are safe. The benefits of exercise far outweigh the minor risk of having a little more coronary calcium”.

Ready for the next bout?

  • Edited by Dr. Gianfrancesco Cormaci, PhD, specialist in Clinical Biochemistry.

Scientific references

Hieda M et al., Levine BD. J Physiol. 2019; 597(2):419-29. 

McNamara DA et al., Levine BD. Circulation 2018 Nov 10. 

La Gerche A et al. Heart Lung Circ. 2018; 27(9):1116-1120.

Sarma S, Levine BD. Cardiol Clin. 2016 Nov; 34(4):603-608. 

Opondo MA et al. Clin Sports Med. 2015 Jul; 34(3):391-404.

Dott. Gianfrancesco Cormaci
- Laurea in Medicina e Chirurgia nel 1998 (MD Degree in 1998) - Specialista in Biochimica Clinica nel 2002 (Clinical Biochemistry residency in 2002) - Dottorato in Neurobiologia nel 2006 (Neurobiology PhD in 2006) - Ha soggiornato negli Stati Uniti, Baltimora (MD) come ricercatore alle dipendenze del National Institute on Drug Abuse (NIDA/NIH) e poi alla Johns Hopkins University, dal 2004 al 2008. - Dal 2009 si occupa di Medicina personalizzata. - Guardia medica presso strutture private dal 2010 - Detentore di un brevetto sulla preparazione di prodotti gluten-free a partire da regolare farina di frumento immunologicamente neutralizzata (owner of a patent concerning the production of bakery gluten-free products, starting from regular wheat flour). - Responsabile del reparto Ricerca e Sviluppo per la società CoFood s.r.l. (leader of the R&D for the partnership CoFood s.r.l.) - Autore di un libro riguardante la salute e l'alimentazione, con approfondimenti su come questa condizioni tutti i sistemi corporei. - Autore di articoli su informazione medica, salute e benessere sui siti web salutesicilia.com e medicomunicare.it

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