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Who has a bigger heart: a 150-lb marathoner, or a 300-lb World’s Strongest Man competitor? And more importantly, whose heart is healthier? Believe it or not, this is an actual study just published in the Journal of Strength & Conditioning Research by scientists in Lithuania. They studied 8 Strongmen, 10 marathoners (nationally or internationally competitive in both cases), plus 9 controls.
In general, you wouldn’t expect strength training to do much for the heart — but these competitors are so extreme that you might expect to see some differences, the researchers argue:
Strongmen with their Herculean strength conduct extremely arduous exercises such as lifting, holding, carrying (hundreds of kilograms), pulling, and pushing (tons) during training and competitions, and such tasks trigger a pronounced cardiac pressure overload and, when conducted over an extended period of time, might be expected to impact cardiac size and function to a greater extent than participation in other types of resistance sport.
The results shows that the Strongmen do have big hearts, but pretty much exactly in proportion to their bodies, whereas marathoners have big hearts but small bodies. For example, the thickness of the posterior wall of the heart was, on average, 11.81, 11.82 and 10.99 mm in the Strongmen, marathoners and controls; but when adjusted relative to body surface area, the values were 7.50, 8.56 and 7.50. More to the point, the hearts of the Strongmen don’t appear to function quite as well (the “E/A” column is a measure of diastolic function):
The Strongmen also fared worse on measures of plasma lipids. What does this all mean? None of the results are particularly surprising. But I suppose if you’re a skinny little marathoner, it’s kind of cool to know that your heart is just as big as the dude twice your size single-handedly hauling an 18-wheeler up a hill on TV.
Good to know that you beat strongmen with your heart muscle even if you’re sedentary.
Judging from the e/a graph, strongmen appear to train their hearts in an opposite direction
The difference between controls an strongmen is probably not significant though.
How much does the study of world class athletes tell us about recreational runners or weightlifters?
KMG
Did they control for Steroid use? 🙂
You would expect world-class marathoners to be selected for large hearts even without any training effect, and you would expect world-class strongmen to be selected for large size even before training. Most people would agree that marathoners could potentially make themselves heavier by resistance training, but that the training they actually perform is unlikely to do so.
The study seems to show that 1) strongmen are not selected for large hearts (relative to body size) and 2) their training regimen does not modify heart size.
@Steve P
And HGH!!
@Steve: Actually, they devote quite a long discussion to the possible effects of steroid use! All the Strongmen in the study denied ever having taken steroids, but the authors nonetheless say:
“Possible (though not admitted) AAS [anabolic androgenic steroid] use by Strongmen may have contributed to their lower aerobic capacity (low relative VO2max), above-average absolute heart size, and depressed global diastolic LV function.”
And that’s just part of a longer discussion. (They don’t mention possible EPO use by the marathoners, though!)
@K.M.: In the case of runners, I think we can infer that the cardiac adaptations in elite marathoners are generally similar to what takes place in more casual runners, but more pronounced.
For the Strongmen, on the other hand, their training and lifestyle is quite different even from other serious weightlifters (i.e. power lifters and bodybuilders). As the authors note:
“Strongmen sport is quite a unique and popular non-Olympic ‘‘pure strength’’ sport where athletes are not restricted to body weight categories and implied to have the greatest absolute strength among humans; also, because they are not strictly persecuted by WADA, the anabolic steroid or other banned substance usage among them is believed to be widespread and intense. In addition, anecdotal evidence about the avoidance of the aerobic exercise and copious amounts of usually not very healthy foods consumed may lead one to think of the lifestyle of Strongmen as not really healthy and thus warrants to consider them as a group of athletic individuals with increased risk for cardiovascular disease and other health problems.”
So the Strongmen aren’t just “the same but more extreme” as casual weightlifters.
@Phil: “The study seems to show that 1) strongmen are not selected for large hearts (relative to body size) and 2) their training regimen does not modify heart size.”
Yes, I think the researchers would say your second point is one of the key results of this study.
As for the point about selection for heart size, that’s an interesting one that I’ve never really thought about. My assumption has always been that enlarged heart is a consequence rather than a cause of elite endurance performance. (And there’s no doubt that endurance training does make the heart bigger.) But do the athletes who end up excelling in endurance sports START with bigger hearts? I guess it wouldn’t be surprising, in the same way that they likely have high untrained VO2max in addition to high VO2max training response. But is there any evidence that this is the case?
@RH: Yes, as far as heart health goes, doing nothing appears to be better than competing in a Strongman competition! Not surprising, given what the researchers describe as “the avoidance of the aerobic exercise and copious amounts of usually not very healthy foods.” Still, if your car ever gets stuck in the mud and there are no tow trucks available, the ability to pull several tons singlehandedly could be useful. 🙂
@alex
“A bucket of eggs a day keeps the tow truck at bay”