scientificamerican.com - Ultra Marathons Might Be Ultra Bad for your Heart
By Katherine Harmon. June 4, 2012
blogs.scientificamerican.com/observations/2012/06/04/ultra-marathons-might-be-ultra-bad-for-your-heart
Excerpt:
<<The researchers found that many of these athletes had temporarily elevated levels of substances that promote inflammation and cardiac damage. One study found that as many as half of runners in the midst of, or who have just finished, a marathon show these spikes, which can last for days after an event. And over time and with repeated exposure, these compounds can lead to scarring of the heart and its main arteries as well as to enlarged ventricles—all of which can in turn lead to dangerous irregular heart beats (arrhythmia) and possibly sudden cardiac death.>>
<<Earlier this year ultra runner Micah True, also known as Caballo Blanco, made famous by Christopher McDougall’s book Born to Run (Knopf, 2009) for running with the Tarahumara tribes in Mexico, died at the age of 58 while on a relatively short trail run. The medical report concluded that he had a scarred, enlarged heart and likely died from arrhythmia.>>
<<Screening for factors to find people who might be at a particular risk so far is unproven and would likely be expensive. So the researchers suggest that athletes dial back intense exercise to about an hour per day (sessions can be longer if exercise is less rigorous) or at least have regular visits with their doctors to check up on their heart health.>>
<<An analysis published May 30 in PLoS ONE [1] also highlights potential downsides of exercise for some people. Claude Bouchard of the Human Genomics Laboratory at the Pennington Biomedical Research Center in Baton Rouge Louisiana, and his colleagues report that in many exercise studies, moderate to intense exercise elevated one or more indicators of risk for cardiac disease or diabetes in a subset (about 10 percent) of the population in the analysis. The authors did not follow the subjects to see if these people were actually more likely to have poor health outcomes, however. And for the rest of the subjects, most of them saw improvements in these risk factors.
But the new findings do not negate the benefits of regular exercise for most people. It adds an average of seven extra years of life expectancy, and it also increases the likelihood that people will spend more of those years relatively trim and in good health. “Exercise is one of the most important things you need to do on a daily basis,” O’Keefe said. But, he noted, “extreme exercise is not really conductive to great cardiovascular health. Beyond 30 to 60 minutes per day, you reach a point of diminishing returns.”
Indeed, a long-term study of 52,000 runners found that those who ran one to 20 miles a week spaced out over two to five days and at an 8.5- to 10-minute mile lived longest.>>
--------------------------------
1. Reference paper:
- Bouchard C, Blair SN, Church TS, Earnest CP, Hagberg JM, et al. (2012) Adverse Metabolic Response to Regular Exercise: Is It a Rare or Common Occurrence? PLoS ONE 7(5): e37887. doi:10.1371/journal.pone.0037887
plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0037887
ABSTRACT
Background
Individuals differ in the response to regular exercise. Whether there are people who experience adverse changes in cardiovascular and diabetes risk factors has never been addressed.
Methodology/Principal Findings
An adverse response is defined as an exercise-induced change that worsens a risk factor beyond measurement error and expected day-to-day variation. Sixty subjects were measured three times over a period of three weeks, and variation in resting systolic blood pressure (SBP) and in fasting plasma HDL-cholesterol (HDL-C), triglycerides (TG), and insulin (FI) was quantified. The technical error (TE) defined as the within-subject standard deviation derived from these measurements was computed. An adverse response for a given risk factor was defined as a change that was at least two TEs away from no change but in an adverse direction. Thus an adverse response was recorded if an increase reached 10 mm Hg or more for SBP, 0.42 mmol/L or more for TG, or 24 pmol/L or more for FI or if a decrease reached 0.12 mmol/L or more for HDL-C. Completers from six exercise studies were used in the present analysis: Whites (N = 473) and Blacks (N = 250) from the HERITAGE Family Study; Whites and Blacks from DREW (N = 326), from INFLAME (N = 70), and from STRRIDE (N = 303); and Whites from a University of Maryland cohort (N = 160) and from a University of Jyvaskyla study (N = 105), for a total of 1,687 men and women. Using the above definitions, 126 subjects (8.4%) had an adverse change in FI. Numbers of adverse responders reached 12.2% for SBP, 10.4% for TG, and 13.3% for HDL-C. About 7% of participants experienced adverse responses in two or more risk factors.
Conclusions/Significance
Adverse responses to regular exercise in cardiovascular and diabetes risk factors occur. Identifying the predictors of such unwarranted responses and how to prevent them will provide the foundation for personalized exercise prescription.
plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0037887
--------------------------------
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scientificamerican.com - Study Sheds Light on Hidden Heart Danger for Athletes
By Sarah Graham. April 22, 2002
scientificamerican.com/article.cfm?id=study-sheds-light-on-hidd
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scientificamerican.com - Fit Body, Fit Mind? Your Workout Makes You Smarter [Preview]
By Christopher Hertzog, Arthur F. Kramer, Robert S. Wilson and Ulman Lindenberger. July 1, 2009
scientificamerican.com/article.cfm?id=fit-body-fit-mind
By Katherine Harmon. June 4, 2012
blogs.scientificamerican.com/observations/2012/06/04/ultra-marathons-might-be-ultra-bad-for-your-heart
Excerpt:
<<The researchers found that many of these athletes had temporarily elevated levels of substances that promote inflammation and cardiac damage. One study found that as many as half of runners in the midst of, or who have just finished, a marathon show these spikes, which can last for days after an event. And over time and with repeated exposure, these compounds can lead to scarring of the heart and its main arteries as well as to enlarged ventricles—all of which can in turn lead to dangerous irregular heart beats (arrhythmia) and possibly sudden cardiac death.>>
<<Earlier this year ultra runner Micah True, also known as Caballo Blanco, made famous by Christopher McDougall’s book Born to Run (Knopf, 2009) for running with the Tarahumara tribes in Mexico, died at the age of 58 while on a relatively short trail run. The medical report concluded that he had a scarred, enlarged heart and likely died from arrhythmia.>>
<<Screening for factors to find people who might be at a particular risk so far is unproven and would likely be expensive. So the researchers suggest that athletes dial back intense exercise to about an hour per day (sessions can be longer if exercise is less rigorous) or at least have regular visits with their doctors to check up on their heart health.>>
<<An analysis published May 30 in PLoS ONE [1] also highlights potential downsides of exercise for some people. Claude Bouchard of the Human Genomics Laboratory at the Pennington Biomedical Research Center in Baton Rouge Louisiana, and his colleagues report that in many exercise studies, moderate to intense exercise elevated one or more indicators of risk for cardiac disease or diabetes in a subset (about 10 percent) of the population in the analysis. The authors did not follow the subjects to see if these people were actually more likely to have poor health outcomes, however. And for the rest of the subjects, most of them saw improvements in these risk factors.
But the new findings do not negate the benefits of regular exercise for most people. It adds an average of seven extra years of life expectancy, and it also increases the likelihood that people will spend more of those years relatively trim and in good health. “Exercise is one of the most important things you need to do on a daily basis,” O’Keefe said. But, he noted, “extreme exercise is not really conductive to great cardiovascular health. Beyond 30 to 60 minutes per day, you reach a point of diminishing returns.”
Indeed, a long-term study of 52,000 runners found that those who ran one to 20 miles a week spaced out over two to five days and at an 8.5- to 10-minute mile lived longest.>>
--------------------------------
1. Reference paper:
- Bouchard C, Blair SN, Church TS, Earnest CP, Hagberg JM, et al. (2012) Adverse Metabolic Response to Regular Exercise: Is It a Rare or Common Occurrence? PLoS ONE 7(5): e37887. doi:10.1371/journal.pone.0037887
plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0037887
ABSTRACT
Background
Individuals differ in the response to regular exercise. Whether there are people who experience adverse changes in cardiovascular and diabetes risk factors has never been addressed.
Methodology/Principal Findings
An adverse response is defined as an exercise-induced change that worsens a risk factor beyond measurement error and expected day-to-day variation. Sixty subjects were measured three times over a period of three weeks, and variation in resting systolic blood pressure (SBP) and in fasting plasma HDL-cholesterol (HDL-C), triglycerides (TG), and insulin (FI) was quantified. The technical error (TE) defined as the within-subject standard deviation derived from these measurements was computed. An adverse response for a given risk factor was defined as a change that was at least two TEs away from no change but in an adverse direction. Thus an adverse response was recorded if an increase reached 10 mm Hg or more for SBP, 0.42 mmol/L or more for TG, or 24 pmol/L or more for FI or if a decrease reached 0.12 mmol/L or more for HDL-C. Completers from six exercise studies were used in the present analysis: Whites (N = 473) and Blacks (N = 250) from the HERITAGE Family Study; Whites and Blacks from DREW (N = 326), from INFLAME (N = 70), and from STRRIDE (N = 303); and Whites from a University of Maryland cohort (N = 160) and from a University of Jyvaskyla study (N = 105), for a total of 1,687 men and women. Using the above definitions, 126 subjects (8.4%) had an adverse change in FI. Numbers of adverse responders reached 12.2% for SBP, 10.4% for TG, and 13.3% for HDL-C. About 7% of participants experienced adverse responses in two or more risk factors.
Conclusions/Significance
Adverse responses to regular exercise in cardiovascular and diabetes risk factors occur. Identifying the predictors of such unwarranted responses and how to prevent them will provide the foundation for personalized exercise prescription.
plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0037887
--------------------------------
Related articles in Scientific American:
scientificamerican.com - Study Sheds Light on Hidden Heart Danger for Athletes
By Sarah Graham. April 22, 2002
scientificamerican.com/article.cfm?id=study-sheds-light-on-hidd
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
scientificamerican.com - Fit Body, Fit Mind? Your Workout Makes You Smarter [Preview]
By Christopher Hertzog, Arthur F. Kramer, Robert S. Wilson and Ulman Lindenberger. July 1, 2009
scientificamerican.com/article.cfm?id=fit-body-fit-mind
