We often think of heart disease as clogged arteries or a heart attack. But there is another, quieter way that a lifetime on the couch can harm the heart — and researchers have given it a striking name: “exercise deficiency syndrome.”
The heart is a muscle, and muscles shrink when unused
Just like the muscles in your arms and legs, the heart gets stronger and more flexible when it is regularly challenged, and smaller and stiffer when it is not. Decades of sitting — at work, in the car, and in front of screens — can lead to a heart that is physically smaller and less “stretchy.” Many adults now spend more than 8 hours a day sitting (La Gerche et al., Journal of the American College of Cardiology, 2022).
A small, stiff heart cannot fill and pump as much blood with each beat. For everyday life that may feel fine, but when extra demand arrives — climbing stairs, carrying groceries, fighting an illness — the heart simply cannot keep up (La Gerche et al., Journal of the American College of Cardiology, 2022).
A leading cause of a common kind of heart failure
This matters because of a condition called heart failure with preserved ejection fraction, or HFpEF. In this form of heart failure, the heart squeezes normally but is too stiff to relax and fill properly, leaving people breathless, tired, and swollen. It is one of the fastest-growing heart conditions, especially in older adults.
Scientists have found that physical inactivity, obesity, and a sedentary lifestyle specifically raise the risk of HFpEF — more so than other kinds of heart failure — and they do so in a dose-dependent way: the less active a person is, the higher the risk (Borlaug et al., Journal of the American College of Cardiology, 2023). That is why experts increasingly describe HFpEF as, at its root, an “exercise deficiency syndrome” (La Gerche et al., Journal of the American College of Cardiology, 2022).
The damage builds slowly and silently over decades. By the time symptoms appear — often around age 60, when heart failure rates start to climb — the sedentary habits have usually been in place for many years. The encouraging flip side: this is one of the most preventable paths to heart failure, and the best time to act is long before any symptoms begin.
Exercise helps almost every part of your health
Staying active does far more than protect against HFpEF. Regular physical activity is one of the most powerful tools available for health, and the benefits reach nearly every organ (Swift et al., American Heart Association, 2026). Regular exercise:
- Lowers blood pressure — aerobic exercise reduces resting blood pressure, with meaningful drops in people who have hypertension (Swift et al., American Heart Association, 2026).
- Improves blood sugar — it increases the body’s sensitivity to insulin and lowers the risk of developing type 2 diabetes (Tucker et al., Journal of the American College of Cardiology, 2022).
- Improves cholesterol — it raises “good” HDL cholesterol and lowers triglycerides (Swift et al., American Heart Association, 2026).
- Reduces the risk of heart attack and stroke — large population studies link higher activity levels to substantially lower rates of cardiovascular disease, diabetes, and stroke (Zhao et al., BMC Cardiovascular Disorders, 2025).
- Builds fitness and strength — higher cardiorespiratory fitness is tied to lower rates of heart disease and death from any cause, and even modest fitness gains matter (Swift et al., American Heart Association, 2026).
- Calms inflammation and helps blood vessels work better — it improves the lining of blood vessels and shifts the immune system toward a less inflammatory state (Bhardwaz et al., Atherosclerosis, 2026).
How much is enough?
National guidelines recommend that adults aim for at least 150 to 300 minutes of moderate activity per week — such as brisk walking — or 75 to 150 minutes of more vigorous activity, plus muscle-strengthening activity on 2 or more days each week (Swift et al., American Heart Association, 2026).
The most important message, though, is that something is far better than nothing. Health benefits begin even with amounts of activity below these targets, and the biggest gains are seen when the least-active people simply start moving more (Swift et al., American Heart Association, 2026; Zhao et al., BMC Cardiovascular Disorders, 2025). Even a single session of activity can lower blood pressure and improve blood sugar that same day (Swift et al., American Heart Association, 2026).
The bottom line
The heart, like any muscle, follows the old rule: use it or lose it. A lifetime of regular movement helps keep it properly sized, supple, and strong — and may be one of the best defenses we have against a common and disabling form of heart failure. It is never too early, or too late, to start.
This article is for general information and is not a substitute for personal medical advice. Talk with your healthcare provider before starting a new exercise program, especially if you have a heart condition or other health concerns.
– Melissa Kjos, MD is Health West’s Medical Director and sees patients at Health West Pocatello. She completed medical school at Oregon Health and Science University and her medical residency at Health West ISU. Dr. Kjos enjoys traveling, camping, jogging, reading and spending time with her family.
