I run leisurely… the most I have run is 5K and am happy to get the target below 30 minutes. I love the feeling of rush when you reach your goal target and I guess that’s what keeps marathoners going for more. A lot of my friends are convincing me to run a marathon…I doubt if Ill ever do that. A 42 K marathon…running for that long will probably take me 6 hours…hehe. Anyway, the question that has always come to my mind is this: is running too long healthy or can it do harm long term?
In the recent American College of Cardiology meeting, the question of distance running and its effect on health was discussed. Ill quote the article published recently in Heartwire online:
Presenting the results of the study at the American College of Cardiology (ACC) 2010 Scientific Sessions, Schwartz, along with senior investigator Dr Robert Schwartz (Minneapolis Heart Institute, MN), his father, said that at least three runners have died this year during marathons, and three runners died during the 2009 Detroit Marathon, a race that included nearly 4000 finishers. Runners are typically considered a healthy subgroup of the general population, so these deaths are usually high profile and attract a great deal of media attention. One recent estimate suggests the rate of sudden cardiac death among marathoners is rare, roughly 0.8 per 100 000 participants.
In this study, the father-and-son team, both runners, wanted to assess coronary artery plaque in an elite group of marathon runners and compare their arteries with a control group. They identified 25 runners who completed the Minneapolis-St Paul Twin Cities Marathon every year for 25 consecutive years, thus completing a minimum of 25 marathons.
All subjects underwent coronary computed tomography angiography (CTA) using a 64-slice machine. Compared with controls, marathoners had significantly more calcified plaque volume—274 mm3 for the marathoners and 169 mm3 for the controls—and higher calcium scores and noncalcified plaque volumes, although the latter two measures did not reach statistical significance.
patient age, systolic blood pressure, total cholesterol, LDL cholesterol, and triglyceride levels were similar between the marathoners and controls, but heart rate, weight, and body-mass index were lower in the runners. Also, HDL-cholesterol levels were significantly higher in the runners than in the controls. The average total- and LDL-cholesterol levels were 190 mg/dL and 115 mg/dL, respectively, in the marathon runners, suggesting that diet is not the reason for the increased calcification.
Jonathan Schwartz said they don’t know why the runners had more plaque in the arteries than the controls and that the findings are “counterintuitive.” However, he pointed out that metabolic and mechanical stresses might be a contributing factor. For example, long-distance runners train at increased heart rates and blood pressures, as well as spend increased time in an anaerobic state, possibly leading to antioxidant damage. Also, damage to the bones might lead to calcium leaking into the bloodstream. They stressed, however, such possible explanations need to be explored further.
Another study, also presented during the ACC meeting, suggested that marathon runners had increased aortic stiffness compared with individuals who exercised recreationally. The researchers, led by Dr Despina Kardara (Athens Medical School, Greece), evaluated blood pressure and aortic elasticity in 42 males and seven females who trained for and ran marathons and 46 men who did not participate in endurance exercise training. On average, the runners trained between two to nine hours per week and had been doing so for periods of 30 months to 21 years.
The marathon runners had significantly higher systolic blood pressure compared with the control group (126 mm Hg vs 115 mm Hg) and higher diastolic blood pressures. Pulse-wave velocity, used to assess aortic stiffness, was significantly higher in the marathon group.
The findings however need further studies. But suffice it to say that too much mechanical stress to any part of the body can do harm than good.
I guess the take home message on this particular study is this:
Try not to push too hard in achieving your goal especially if it entails putting too much pressure on ones body especially the heart… Running is healthy as a form of exercise but anything we do and if we push ourselves to the limit may cause more harm than good.
If you run a marathon…dont stop. Continue to enjoy it but again dont push yourself too hard….
Take Life In A Stride…!