Featured Research

from universities, journals, and other organizations

Why Elite Rowers Have Bigger, Stronger Hearts

Date:
August 15, 2008
Source:
Society for Endocrinology
Summary:
Scientists have unraveled a potential mechanism for how top-level rowers develop enlarged strengthened hearts as a result of long-term intensive training. The research suggests a causal link between naturally occurring hormone levels and strengthening of the heart muscle in professional rowers.

Scientists have unravelled a potential mechanism for how top-level rowers develop enlarged strengthened hearts as a result of long-term intensive training.
Credit: iStockphoto/Gergo Orban

Scientists have unravelled a potential mechanism for how top-level rowers develop enlarged strengthened hearts as a result of long-term intensive training. The research, published in the August edition of Clinical Endocrinology suggests a causal link between naturally occurring hormone levels and strengthening of the heart muscle in professional rowers. Elite rowers were found to have higher levels of insulin-like growth factor 1 (IGF-1) compared to healthy sedentary volunteers. In these athletes, IGF-1 values correlate with enlargement and strengthening of heart muscle cells.

Researchers, led by Dr Giovanni Vitale (University of Milan, Italian Auxologic Institute, Italy) and Professor Gaetano Lombardi (University of Naples Federico II, Italy), measured circulating IGF-1 levels in blood samples from 19 top-level male rowers and 19 age-matched healthy sedentary controls. IGF-1 is a hormone that is produced by the liver in response to growth hormone stimulation. Each subject had their cardiac structure and function measured using standard echocardiography and ‘pulsed Tissue Doppler’, a more effective way of accessing and recording activity, particularly from the right side of the heart. For the rowers, examinations took place during a period of intense physical training, but at least 24 hours following the last athletic activity.

The rowers had higher serum IGF-1 levels compared to controls, but in both groups IGF-1 levels were within the normal range. The rowers’ hearts were also much larger, showing increased cavity dimensions, increased wall thickness, and enhanced muscle function, in both the left and right sides of the heart, compared to controls. In the rowers, IGF-1 levels correlated significantly with several echocardiographic parameters of myocardial contractility. Importantly, these associations remained significant when adjusted for age and heart rate. There were no significant differences in terms of height, weight and blood pressure between the two groups, although as expected, the rowers had significantly lower resting heart rates compared to the control group.

This is the first study to show an independent association between IGF-1 levels and remodelling of the right side of the heart in competitive rowers, and provides clues as to how the body responds and adapts to prolonged physical exercise. IGF-1 promotes muscle growth, and is known to be activated during exercise; IGF-1 levels often remain elevated following a training period1. This research provides a potential mechanism for cardiac remodelling in rowers, whereby an increase in IGF-1 may activate biochemical pathways, which trigger heart muscle growth, resulting in increased cardiac strength and output.

Researcher Dr Giovanni Vitale said: “Cardiac hypertrophy, or enlargement of the heart muscle cells, is a hallmark of top athletes, especially rowers, and is a physical adaptation to increased cardiac load during prolonged periods of exercise. Our results show both the left and right sides of the rowers’ hearts are larger, and function at an enhanced capacity compared to those of the controls. The causes of this strengthening of athletes’ heart muscle are not completely clear. It could be due to the production of growth factors (such as IGF-1) during training. In fact, physical exercise is associated with cardiac haemodynamic changes (pressure and volume overload) able to stimulate the production of growth factors by stretching myocardial fibers.”

“To this end, we investigated levels of the hormone insulin-like growth factor-1 (IGF-1), and found significantly increased levels in the rowers compared to the control group, although in both groups IGF-1 levels were within the normal range. Furthermore, higher IGF-1 levels in the rowers’ bloodstream correlated significantly with better heart performance. These results highlight a possible biochemical mechanism for cardiac hypertrophy in elite rowers and suggest a potentially beneficial role for IGF-1 in the remodelling of the heart muscle. This could mean that naturally increased production of IGF-1, occurring as an adaptation to prolonged training, influences biochemical processes that control contraction of the heart muscle in rowers. Further research is now needed to determine the exact relationship between higher production of IGF-1 and cardiac output in elite rowers.”


Story Source:

The above story is based on materials provided by Society for Endocrinology. Note: Materials may be edited for content and length.


Cite This Page:

Society for Endocrinology. "Why Elite Rowers Have Bigger, Stronger Hearts." ScienceDaily. ScienceDaily, 15 August 2008. <www.sciencedaily.com/releases/2008/08/080807222006.htm>.
Society for Endocrinology. (2008, August 15). Why Elite Rowers Have Bigger, Stronger Hearts. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2008/08/080807222006.htm
Society for Endocrinology. "Why Elite Rowers Have Bigger, Stronger Hearts." ScienceDaily. www.sciencedaily.com/releases/2008/08/080807222006.htm (accessed July 23, 2014).

Share This




More Health & Medicine News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Courts Conflicted Over Healthcare Law

Courts Conflicted Over Healthcare Law

AP (July 22, 2014) Two federal appeals courts issued conflicting rulings Tuesday on the legality of the federally-run healthcare exchange that operates in 36 states. (July 22) Video provided by AP
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Scientists Find New Way To Make Human Platelets

Scientists Find New Way To Make Human Platelets

Newsy (July 22, 2014) Boston scientists have discovered a new way to create fully functioning human platelets using a bioreactor and human stem cells. Video provided by Newsy
Powered by NewsLook.com
Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins