Tuesday, January 3, 2012

Weight Training: a Real Heart-Breaker? by Jerry Brainum

In the past many physicians advised their patients not to lift weights because it “strained” the heart. That advice was no doubt largely based on firsthand observation of men lifting heavy weights, with all the signs of stress and strain apparent in the lifters’ blood-engorged faces. Lifting heavy weights, the reasoning went, dangerously increased blood pressure, thereby placing undue stress on the heart.

   More recent research shows that a well-designed weight-training program not only isn’t bad for most hearts but also provides benefits previously ascribed to aerobic exercise. Weight training, like aerobics, can increase the levels of high-density lipoprotein, the protective cholesterol carrier in the blood. Lifting weights also increases insulin sensitivity, and increased insulin control is beneficial for cardiovascular protection.

   It’s true that lifting heavy weights, particularly in positions that promote increased pressure on the vascular system, such as squats and leg presses, does significantly increase blood pressure. That increase, though, occurs only during the actual lift. Studies show that your body adjusts to the temporary rise in blood pressure by producing changes in the blood vessels that result in a lower resting blood pressure. So it all evens out.

   There are, however, exceptions to the rule—for example, in the case of medical conditions that involve structural weaknesses of blood vessel walls. If you have an aneurysm in any of your blood vessels, increasing blood pressure may cause it to explode, with possibly calamitous results. (An aneurysm is dilation of a blood vessel wall that causes a weakness in that portion of the wall. When it blows, it’s comparable to a tire blowing out.)

   In a recent letter to the Journal of the American Medical Association, several Yale University School of Medicine physicians reported on the incidence of a rupture of the aorta, the main artery leading out of the heart, in five patients.1 The medical diagnosis was acute dissection of the ascending aorta. In plain English that means that these people experienced aorta tearing from the inside, likely the result of an undiagnosed aneurysm. That’s the condition that caused the sudden death of comedian John Ritter.

   While dissection of the aorta is usually found in people over 40 with a long history of hypertension, or high blood pressure, the cases reported in JAMA involved five patients ranging in age from 19 to 53 with no previously diagnosed aneurysm or high blood pressure. None of them had Marfan’s syndrome, a congenital weakness of connective tissue in which aortic dissection often occurs. A top-level female volleyball player died a few years ago after her aorta exploded suddenly from Marfan’s syndrome. Some doctors think that, based on his body structure, Abraham Lincoln suffered from that disease, which would have likely killed him if Booth’s bullet hadn’t gotten to him first in April 1865.

   The common denominator in the five patients cited in the JAMA letter was that all were engaged in some type of heavy lifting when their symptoms became apparent. Two of them were lifting weights, one was trying to move a heavy stone structure, and the other two were doing pushups.

   No one knows for sure what causes this weakness in the wall of blood vessels. The symptoms feel like a heart attack, with the exception of a ripping sensation deep in the chest. Some suggest that an increased accumulation of plaque deposits in the arteries (atherosclerosis) weakens the wall. Others think the aneurysm is just there to begin with, a sort of birth defect that becomes apparent only when sufficient pressure is exerted on it—as can occur with lifting heavy weights.

   The doctors who wrote the JAMA letter suggest that those at risk include people with known aneurysms or connective tissue disease (such as Marfan’s syndrome), a family history of aneurysms or dissection, high blood pressure and people middle-aged or older; the aorta becomes stiffer with age, thus predisposing it to increased pressure and blowout. One study found that garlic appears to decrease age-related aortic stiffness.

   The way to deal with this is by having a medical scan of your aorta if you fall into any of the risk-factor patterns. Doctors also advise you not to lift more than your bodyweight, since doing so raises the blood pressure to high levels that could precipitate an aortic dissection. That last suggestion is likely to fall on deaf ears in hardcore bodybuilders, who want to lift heavy for strength and muscle gains. So it’s especially vital to undergo medical tests if you have any history of the conditions linked to aortic dissection.

1 Elefteriades, J.A., et al. (2003). Weight lifting and rupture of silent aortic aneurysms. JAMA. 290:2803.

©,2013 Jerry Brainum. Any reprinting in any type of media, including electronic and foreign is expressly prohibited.

Please consider joining this blog by clicking on the blue "join this site" button to the right of this blog. This will ensure that new blogs continue to be published. It costs nothing, and takes only a few seconds. Thank you.

See Jerry's book at       www.jerrybrainum.com