If you’ve had a heart attack , worry about a repeat incident may loom large. Now a new study shows that swapping out 30 minutes of sitting with 30 minutes of any level of physical activity, even slow walking, reduced the risk of having a second heart attack by 50 percent.e60dc2a1-f33c-4a05-9b50-8e3e8e597629ed749dc4-5a89-4418-884d-76bd1bb6496c “Our findings highlight that sedentary behavior is a toxic, harmful behavior that can impact recovery and future health risk after a heart event,” says lead author Keith Diaz, PhD , certified exercise physiologist and associate professor of behavioral medicine at Columbia University Medical Center in New York City. The 50 percent reduction in risk from replacing 30 minutes of sedentary time with light-intensity activity underscores an important public health message: Doing something is better than doing nothing, says Dr. Diaz. “This is especially relevant for people recovering from a heart event who may find moderate or vigorous activity difficult or scary,” he says. Study Followed Heart Attack Survivors for a Month Diaz and his team followed more than 600 people ages 21 to 96 years old who were treated for a heart attack or chest pain in the emergency department at a single hospital system in New York City. Participants wore a Fitbit-type device for a median of 30 consecutive days after leaving the hospital to measure the amount of time they spent sitting or being inactive each day. What daily habits looked like in each group:
Any Reduction in Sitting Lowered Risk of a Second Heart Attack Investigators tracked additional heart events and deaths for one year and analyzed the data according to how much people moved, sat, and slept. Key study findings: The least active people had more than twice the risk of having another heart problem or dying within a year, compared with the most active. Swapping 30 minutes of sitting each day for moderate to vigorous activity (like brisk walking or cycling) lowered risk by 61 percent. Swapping 30 minutes of sitting each day for light activity (like slow walking or household chores) lowered risk by 50 percent. Replacing sitting with sleeping lowered risk by 14 percent. Bed Rest Can Be a Killer Although it may seem counterintuitive, the study showed that staying active after a heart attack is linked to better outcomes. “Fifty years ago, coronary patients were put on bed rest for six weeks post heart attack and more than 20 percent died within a year,” says Eleanor Levin, MD , a cardiologist and clinical professor of medicine at Stanford Health Care in California, who was not involved in the study. “Now that rate has decreased to about 5 percent with modern therapies and early mobilization.” Early mobilization means movement as soon afterwards a heart attack as possible, ideally within the first few days of hospitalization, says Dr. Levin. These findings support earlier studies that have also found less sitting and more movement improve all kinds of health outcomes, says Carl Lavie Jr., MD , a cardiologist and professor of Internal Medicine at the University of Queensland Medical School–Ochsner Health in New Orleans, Louisiana, who was not involved in this study. These findings show that this holds true in people who have recently had a heart attack, says Dr. Lavie. Why Movement Matters Why is exercise so helpful after a heart attack? “We think that regular movement helps to activate the muscles to serve as better blood sugar and cholesterol regulators, which is good for heart health,” says Diaz. Sitting, on the other hand, creates bends and constrictions in the blood vessels of the legs. This ultimately changes blood flow and can lead to increases in blood pressure, he says. “We think that regular movement can help prevent the increases in blood pressure by regularly restoring blood flow to the legs, and this also can have heart health benefits ,” says Diaz. Getting More Sleep Can Also Reduce Heart Attack Risk While exercise still provides the best “bang for your buck” healthwise, the findings on sleep are good news for people who may not have the time, ability, or desire to exercise, says Diaz. “Our finding that replacing 30 minutes of sedentary time with sleep can lower risk by 14 percent offers an encouraging message. Even getting an extra half-hour of sleep, rather than spending that time sitting on your phone or watching one more episode on Netflix, can support recovery and reduce risk. This is a small, doable step that can still make a meaningful difference for your health,” he says. Unlike sitting, sleep promotes healthful, restorative processes that help regulate blood pressure, reduce inflammation, and support heart function, says Diaz. “Sitting for hours at a time does the opposite. It increases blood pressure, can trigger chronic inflammation, and contributes to poor heart health,” he says. Cardiac Rehab and 5-Minute Walking Breaks Can Make a Big Difference Levin recommends cardiac rehab , a medically supervised program that can help improve your cardiovascular health if you’ve had a heart attack or other types of heart surgery or heart disease. Even though cardiac rehab has been proven to reduce future heart attacks, it’s underutilized in the United States, she says. “Participating in cardiac rehabilitation has been shown in recent studies to reduce mortality by 47 percent, but less than 1 in 4 coronary patients begin and finish cardiac rehab,” says Levin. Diaz suggests taking five-minute walking breaks at whatever pace is comfortable for you every half-hour to hour. “In our lab, we have found that the harmful effects of sitting on blood sugar levels and blood pressure were greatly reduced by taking a five-minute light walk every half-hour. While we did find that walks every hour also reduced some of the harmful effects of sitting, it was the five-minute light walk every half-hour which had the greatest effects,” he says.