A can of Coke or Pepsi, then, basically takes you to the AHA's upper limit on the recommended amount of added sugar Americans should ingest on a daily basis. The association's primary concern is the number of excess calories that added sugars sneak into our diets and pile onto our waistlines, which can contribute to metabolic changes that increase the chances of developing a host of diseases.
Bottom line: According to the AHA, women should get no more than 100 calories per day of added sugars and men should stop at 150 calories per day. Watch out for surprising foods where sugar lurks, like fortune cookies, baked beans, ketchup, and flavored popcorn.
Resting heart rate. How hard does your heart have to work—and how fast does it have to pump—to get oxygen-rich blood throughout your body? A lower number suggests your cardiovascular system is more efficient at doing this. Thus, a highly trained athlete can have a resting heart rate in the 40s, says Whiteson.
And while the research is still emerging on what one's resting heart rate predicts about heart disease risk, a picture is beginning to take shape. "There is certain evidence to support [the idea that] a higher resting heart rate is associated with heart disease," especially ischemic heart disease, he says, which involves reduced blood flow (and oxygen) getting to heart arteries and the heart muscle. This effect seems to be more pronounced in women than in men, but a study in the Journal of Epidemiology and Community Health suggested that in women up to the age of 70, every 10-beats-per-minute increase in resting heart rate boosted the risk of dying from ischemic heart disease by 18 percent. In men, the risk was increased by 10 percent for every extra 10 beats per minute, and age didn't have an impact. The study also found that women who got high levels of physical activity were able to reduce their risk of death considerably, compared with those who did little or no activity. The same effect was not found in men, but the researchers suggest the results may have been skewed because men tend to overestimate how much exercise they get.
Bottom line: A normal resting heart rate is between 60 and 100 beats per minute. Check yours by finding your wrist's pulse, counting the beats in a 15-second period, then multiplying by four.
Hours of sleep per night. An overcaffeinated America seems to perpetually crave more shut-eye. And evidence is cropping up to suggest that a poor night's sleep is not only felt the next day but could have implications for one's heart over the long term. It is well established that sleep apnea, which results in numerous interruptions to breathing while asleep, is associated with stroke and coronary artery disease.
The reason is not clear, says Whiteson, but it's been hypothesized that people with disrupted sleep breathing have higher blood pressure overall because they don't get the restorative sleep that normally allows blood pressure to go down and gives the cardiovascular system a break during slumber. And a study in the Journal of the American Medical Association showed that middle-aged people who got five hours of shut-eye or less a night had a greater risk of developing coronary artery disease than those who got eight hours. The clue was the beginnings of calcium buildup in their arteries, found by CT scanning long before the disease process would normally be picked up.
Bottom line: Get eight hours of sleep per night. Making it happen isn't easy, we know.
Exercise. You've heard it a thousand times over, and the message stays the same: Regular, heart-thumping exercise offers a multitude of health benefits, particularly for cardiovascular fitness. Perhaps clinicians (and health writers) keep bashing us over the head with that fact because of the eye-popping number of American adults who reported getting zero vigorous activity in a 2008 Centers of Disease Control and Prevention survey: 59 percent.