Editor’s note: This is the third in a series of four columns from Penn Medicine physicians this month on heart health.

More than half of Americans age 40 and older will develop heart disease. Many factors contribute to an individual’s risk, including genes inherited from one’s family and behaviors such as smoking, inactivity, unhealthy diet, and poor sleep quality.

Changing long-held habits is hard. But healthy behaviors can be more effective tools to reduce one’s risk for heart disease than many medical interventions. In fact, adhering to a healthy lifestyle can dramatically reduce your risk of suffering a heart attack or stroke and decrease your likelihood of having high blood pressure, high cholesterol, and diabetes.

What do we mean when we talk about a healthy lifestyle?

1. If you smoke, quit. About 15 percent of adults in the U.S. smoke. For them, quitting is the most important intervention to protect against heart disease. People who quit reduce their risk of suffering a heart attack by nearly 50 percent. Set realistic goals and consider receiving help from a professional. The effects of e-cigarettes on the heart are still unknown, so cessation is still the best option.

2. Eat healthy. The food we eat contributes to our blood pressure, sugar, cholesterol, and weight, so consume meals with natural and unprocessed ingredients. Consider a plant-based diet. If you use oil for cooking or dressing, make it heart-healthy oil (such as olive or canola) that is low in saturated fat. Practice moderation.

3. Move. Aside from smoking cessation, exercising is arguably the most effective way to mitigate your risk for heart disease. Active people generally have lower rates of heart attack. Plus, individuals with higher levels of fitness are more likely to survive a heart attack and experience smaller degrees of damage to the heart muscle.

How much and what kind of exercise?

The American Heart Association recommends at least 150 minutes of moderate activity, such as brisk walking or slow biking, or 75 minutes of vigorous aerobic activity, like running or swimming laps, every week.

Understanding exercise intensity can help you identify whether you are pushing yourself hard enough to condition the heart muscle. Tracking your heart rate can be a useful gauge of your intensity. For example, a rough prediction for your maximum achievable heart rate is to subtract your age from 220. From there, identify 50 to 70 percent of that number – that’s your target heart-rate range to pursue during exercise to ensure moderate intensity. The window is specific to each individual and varies based on a number of factors including age and conditioning. While walking at a brisk pace may be low intensity for a 20-year-old, the same exercise may serve as a moderate- or high-intensity workout for people in their 60s.

Start slow. Increase the workload and intensity over time to ensure safe, gradual conditioning. If you develop symptoms or have a history of heart issues, have a conversation with your doctor about potential testing and goals. Ultimately, the key is to identify an activity you enjoy so you incorporate it into your daily lifestyle.

People often cite a lack of time as a reason for not exercising. However, recent research suggests that high-intensity interval training (HIIT) can yield similar cardiovascular benefits to those achieved from traditional longer-duration moderate sessions. HIIT workouts – which involve short intervals of high-intensity exercise, followed by lower-intensity recovery periods – can range anywhere from 10 to 60 minutes depending on the program. Many local gyms offer aspects of HIIT in their classes, and you can even find HIIT workouts via mobile applications.

Technology and teamwork

Fitness wearables – whether it’s an activity band, fitness watch, or clip-on tracker – can help users quantify their exercise and stay on track to meet their goals. Newer devices with heart-rate monitors enable users to view their exercise intensity and the time spent at that level of exercise. Step count is another important metric. People who walk about 6,000 to 8,000 steps per day tend to achieve 30 minutes of moderate activity, research has found.

Becoming more active is simple, but it is not always easy. Teaming up with friends, coworkers, or family can provide the social support and accountability that will keep you on track. The key is to make exercise a habit, hard-wired into our brains. The 30-minute walk or hour-long swimming session eventually should require no more internal debate than waking up and brushing your teeth.

Neel Chokshi, MD, MBA, is the medical director of the Sports Cardiology and Fitness Program and an assistant professor of cardiovascular medicine in the Perelman School of Medicine at the University of Pennsylvania; Douglas Jacoby, MD, is the medical director of the Penn Medicine Center for Preventive Cardiology and Lipid Management and an associate professor of cardiovascular medicine in the Perelman School of Medicine; Christopher Kusmiesz, MS, is an exercise physiologist in the Sports Cardiology and Fitness Program.