Lifting weights, sometimes referred to by the sniffier nom du gymnasium of “strength training,” is not part of everyone's exercise regimen. Most of us, especially the older among us, are happy to focus on our treadmills and ellipticals, knowing that a muscular bodywon't be much good to us if our heart gives out.

Sure, you're not going to get six pack abs and broad chiseled shoulders without pumping a lot of iron, but unless you're angling for a gig as an extra on Spartacus, you don't really need those, do you?

So why lift weights?

One reason might be that it is the secret to long life. A new study from Penn State College of Medicine tracked people over the age of 65 and their exercise habits for 15 years. Nearly a third of them died during that time, and less than 10 percent of the test subjects lifted weights. But those among that elite group were 46 percent less likely to die during the study than everyone else who participated in the research.

“Well, sure,” you say. “If these guys were over 65 and lifting weights they were just in better shape and with a healthier frame of mind to begin with!” Except that after adjusting for body mass index, chronic conditions like diabetes and hypertension, and habits like total physical activity, drinking, and smoking, lifting was still linked to a 19 percent reduced risk of death!

Need your proof a little more a priori? One study found that resistance training works directly against our species' number one killer: it reduces oxidative stress and our overall risk of cancer.

Another reason we lift is that it improves our bone density. This is important at any age but especially as we grow older, when our bodies begin to shed bone mass.

Something else that our bodies discard as they age is lean muscle mass. That process is known as “sarcopenia.” And our bodies just don't shed muscle as we age, it is actually turned into fat – if we don't engage in some strength training to counteract the process.

Although you may be afraid that you will “hurt something” if you start lifting, the happy truth is that strength training can lead to stronger ligaments and tendons, so that you are less likely to hurt yourself during your everyday activity.

And... lifting weights makes us smarter. The University of New Mexico put the lie to the cartoon cliché of the bone-headed muscleman when it published the results of their study that showed how resistance training improved brain cognition, as well as overall mental health.

So those dumbbells? Maybe not so dumb, after all...