Exercise Versus Activity
When I visit with a patient I like to get a sense about how active they are, i.e. do they exercise on a regular basis? As you can imagine most of them don’t (that’s part of the reason they ended up in a cardiologist’s office in the first place) although I have a few whose exercise persistence would rival Lance Armstrong.
Some of my patients simply can’t exercise due to other medical conditions such as severe arthritis, previous stroke, or chronic back pain. I am amazed by a few who can barely walk yet make an effort to get some type of exercise in every day, even if it is nothing more than arm stretches and toe raises. With this group of individuals I just applaud their efforts and hope I can be as stubbornly compliant as they are when I’m an octogenarian.
On the other end of the spectrum are my younger and healthier patients who, when queried about exercise, wax superlative with a narrative about the physical labors their daily schedule requires of them.
“I’m a construction foreman and I regularly walk around the work site. By the end of the day I’m exhausted”
“I work all day. I’m constantly going up and down the stairs and walking back and forth in the kitchen.”
“I’m a farmer so of course I spend my whole day exercising.”
“I stay home with my kids so I race around the whole day long chasing them. I don’t need to exercise with how much activity I get.”
It’s at this point I politely tell them about the difference between activity and exercise.
There’s no better way to burn calories than to keep moving all day long. I know this through personal experience. I came to private practice out of an academic position with the Air Force. For several years I had a nice office where I would convene didactic sessions with my residents and students, see patients, read journals, and write an occasional scholarly article. I’d run up to the cath lab a couple times a day and make rounds when it was my turn to attend on the inpatient service, but mostly my days were spent in my comfortable chair.
When I transitioned to private practice I was surprised to learn that my new group didn’t even have offices for their doctors. We were expected to be on the move so much that we’d never really need a place to park for hours at a time. I quickly adapted by accelerating to a pace that made me look like I was always late for something. As time went on I realized that I was hungry more in a day than I had been in my previous, more sedentary job. After I wore a pedometer for a week (Christmas present from my wife) I realized why—there were days when I would rack up 4 to 6 miles during normal working hours.
I imagine that—like me—the construction foreman, the farmer, the housewife, and the kid-chasing mother all spend a good portion of their day on the move and are rewarded with expended calories and weight control. The question, however, is what does their heart get out of all this?
Normal movement from one place to the next doesn’t typically require much rise in heart rate, and it’s this increase in cardiac workload that provides the most benefit for the blood vessels and muscle of the heart. An example of this is a substance called nitric oxide (NO) that is released by the cells that line the coronary arteries in response to exercise and enhances flow of oxygen-rich blood to the heart muscle (the drug nitroglycerin exerts its salutary effect by stimulating the natural production of NO). Higher heart rates and stronger ventricular contractions yield greater flow of NO into the heart’s capillary bed.
Numerous studies validate the idea that more vigorous, sustained activity is needed to impart the protective effect of exercise on the heart and blood vessels. One such report, published in the Journal of the American Medical Association, showed that cardiac risk dropped in proportion to the level of physical stress the activity induced. A half-hour a day of brisk walking dropped the risk of heart attack by nearly 20 percent, while running an hour or more per week cut the risk by over 40 percent. Less vigorous activity produced no more than a dent in the overall risk of heart attack.
So while it’s good to stay moving on the job or at home (certainly better than a completely sedentary lifestyle) you still have to engage in some type of activity that puts the heart through its paces for at least a half hour a day. Brisk walking is my favorite recommendation if your knees and hips are up to it. I still try to get a run in even on days when I feel like I’ve toured the hospital three dozen times.
Routine aerobic exercise keeps you healthy and makes you feel better, sleep better, think better, and live long enough for your next career: chasing your grandkids around all day.