If you’re 45 or older, you probably diagramed sentences sometime in secondary school. If you’re younger, you probably didn’t — unless you spent a year or two in my class.

I take the time to teach something that has clearly fallen out of favor because I believe in the end result. As students diagram, they learn about sentence structure and gain overall insight into our language. Not only do some become so proficient at diagraming that I’m hard pressed to challenge them, but many also come to truly enjoy the process.

An equal amount, however — or maybe even more — don’t.

Yet in my 30-plus years I have found that even those who detest diagraming — except for the expected malcontent or two — give a good-faith effort. I believe that’s because before we begin, I do my best to sell the students on diagraming’s benefits.

Students, you see, are no different from adults in this regard: They will buy into earnestly attempting a task if they believe in the benefits.

I share my experience with sentence diagraming because recently more than a few adults have told me how difficult it has become to exercise regularly as they grow older. So let me now do my best to sell them and you, too, on the importance of exercising as you age — regardless of your present age.

In short, exercise allows you to keep — at least for a longer time — what aging eventually takes from all of us.

Done regularly and correctly, exercise keeps you from losing muscle mass and aerobic ability. It can also delay the graying of hair, the wrinkling of skin, and the increase of visceral fat in the abdomen, as well as reduce the aches and pains associated with getting older.

More so than any other form of strength training, lifting weights negates the loss of muscle mass. It’s inevitable; after 40 or so, you are going to lose muscle because the nerves that trigger your muscles to fire slowly die and muscle fibers that cease firing do the same.

So the goal becomes to negate nerve death for as long as you can by making the muscles that are still activated by functioning nerves stronger. Later when the rate of nerve death naturally accelerates, the goal becomes not to negate but mitigate the unpreventable loss through lifting weights.

In younger people, lifting relatively heavy weights for fewer repetitions works best to increase muscle mass, but once you turn 45 or so, lifting lighter weights, using higher repetitions, and performing a greater volume works just as well and also lessens the odds of injury. In fact, in a study published in 2012 in the Journals of Gerontology, older men gained more strength and muscle size than younger men when the exercise volume for both was doubled.

But a recent study published in the European Heart Journal suggests that aerobic exercise is even more important than lifting weights in delaying the aging and eventual death of your cells.

It’s based on telomeres, the DNA and proteins at the ends of our chromosomes, which naturally get shorter every time cells divides. Once telomeres get too short, cells lose the ability to divide and subsequently die.

In the study, healthy but less-than-active young adults followed one of three courses of exercise: general endurance training, such as distance running; endurance training augmented with high-intensity intervals, often a mix of slow jogging and fast running; or typical weight lifting. Another group studied continued to lead their less-than-active lives to serve as the control group.

Six months later, 124 of the original 266 participants were still working out and the final tests were taken.

The findings revealed that the young adult who did endurance training with or without the high-intensity intervals experienced an increase in telomere length, but those who only lifted weights did not.

While the study used young adults, lead researcher, professor Ulrich Laufs, of Leipzig University in Leipzig, Germany, still feels that the results show that endurance training “improves healthy aging” regardless of age. Co-author of the study, Dr. Christian Werner of Saarland University in Germany, concurs and adds, “Our data support the European Society of Cardiology’s current guideline recommendations that resistance exercise should be complementary to endurance training rather than a substitute.”

Werner also has an interesting theory particularly on why the slow running interspersed with fast running is so effective: it mimics what happened naturally to our cavemen ancestors when hunting large animals, that surge of adrenaline and sense of frenetic readiness we now call the fight-or-flight feeling.

Another theory on the added advantage to endurance training over weight lifting is that aerobic activity positively affects the level of nitric oxide in the blood, something that’s the goal of many sports-performance supplements, especially beet juice.