LJMU studied a group of 25 runners (aged between 24-62) competing in the "Lakeland" race. 16 of the group competed in the 50 mile race, and the remaining 9 in the 100 mile race. All of the runners had at least 2 years of Ultra Marathon experience, and had trained specifically for the race. None of the participants had any known heart conditions. Each of the 25 subjects would be given a blood test, an ECG and would be weighed before and after the race.
The Results:
- Of the 50 mile competitors, the average completion time was 15 hours, and average weight loss was 2kg.
-Of the 100 mile competitors, the average completion time was 36 hours, and average weight loss was 3 kg.
-The post race blood tests showed that Troponin 1 levels rose significantly in 21 of the 25 subjects. In 3 of the runners, levels were high enough to suggest serious Cardiac damage.
The ECGs carried out before the race are said to have shown slow heart rates along with the electrical changes you would expect from an athlete.
In the post-race race ECGs, there were significant electrical changes in over 50% of the subjects. In some of the subjects, bizarre electrical changes were shown, not usually seen in normal ECGs (At rest or during exercise).
In Professor Somauroo's summary of the results, he stated that the study "suggests that running continuously over 50 or 100 miles may not be good for the heart". The closing statement of the study however, states that "There was no proven correlation between the changes in Cardiac Troponin 1 and the ECG changes."
This study appears to show that a large proportion of Ultra Marathon competitors are likely to suffer some degree of Cardiac Damage. It is however, important to consider how the study was carried out to decide how reliable the results are likely to be.
-The study group was small and therefore may not represent the general condition of Ultra Marathon competitors.
-The Lakeland race, where this study was carried out, suffered very difficult weather conditions. This could have affected the results.
-The subjects may have extremely varied levels of experience, as the only information we're given is that all subjects have been competing in Ultra Marathons for at least 2 years.
-The subjects were not given a full medical check-up prior to the race. This could mean that subjects with unknown heart conditions took part in the study and harmed the validity of the research.
It is expected that further data (Heart function levels) concerning this subject will be released at a later date. This data could go towards creating a greater understanding of the effects extreme endurance events have on the body, and how these adverse affects can be minimised.
Ben Brown
Interesting, but the problem is we have no data about what any of these test results mean when a result of ultra endurance running. We only know they are bad when they occur at rest. Just as a rapid heart beat and rapid respiratory rates which would be abnormal at rest are simply normal responses to exertion. I am 61 years old, have completed over 350 ultra marathons and over 200 marathons, still able to run one or more a month and just last week beat everyone over 50 in the Mystery Mountain Marathon, seems that if I were injuring my heart every time a do an ultra there wouldn't be mich legft after 35 years of doing them.
ReplyDeleteThanks for the comment Rich.
ReplyDeleteI think this study should be considered as a starting point which will spur on further research into the area. At the moment there is a definite lack of information concerning the longer term effects of Ultra Endurance Running.
It would be interesting to see a study which looks at the recovery period following an Ultra-Marathon. Especially looking at the length of time the Troponin I level remains elevated in the blood.
I also feel it would be valuable to consider the factors which caused Tropinin I levels to rise more in some of the study group than others.
There's plenty of work still to do!