6 Factors That Can Cause Cardiovascular Disease in Physically Fit People

Staying physically active is one of the most effective ways to support heart health, but it doesn’t guarantee immunity from cardiovascular disease. Even highly fit individuals—including elite athletes—can experience heart attacks or cardiac events, sometimes without warning. That’s because cardiovascular health is influenced by more than just fitness; genetics, hidden medical conditions, lifestyle choices, and even specific types of exercise can all contribute to risk. Understanding the factors that may impact your heart—regardless of your activity level—is key to staying informed, proactive, and protected.

Six factors that can contribute to cardiovascular disease in physically fit people are:

1. Genetics and family history
2. Silent or undiagnosed risk factors
3. Over-training and extreme endurance exercise
4. Performance-enhancing substances and supplements
5. Stress, sleep, and recovery
6. Misinterpreting symptoms or delaying care

At CardioVascular Health Clinic, our multidisciplinary team of experts and specialists works together to provide a thorough assessment of your cardiovascular health. By combining advanced diagnostics with personalized care, we help identify hidden risk factors and create a plan tailored to your needs. Whether you're an athlete or simply want to stay active, our goal is to keep your heart strong so you can continue doing what you love. With the right guidance and support, you can live a longer, healthier life with confidence.

6 Factors that Can Cause Cardiovascular Disease in Physically Fit People

Cardiovascular disease doesn’t always look like we expect, and it is not limited to people with obvious risk factors such as smoking, obesity, or a sedentary lifestyle. On the contrary, research shows that up to 75% of heart attacks occur in people with “normal” cholesterol levels, and a significant number happen in those who appear outwardly healthy.

Being physically fit exponentially lowers your risk of developing cardiovascular disease, but it doesn’t eliminate it entirely. Cardiovascular disease includes a wide range of conditions, from coronary artery disease (the most common type) to arrhythmias, heart valve disorders, cardiomyopathy, and sudden cardiac arrest. Oftentimes, cardiovascular disease can develop quietly and progress without noticeable symptoms until a serious event occurs, so it’s important to understand what some of these “silent” factors are.

1. Genetics and Family History

When it comes to your risk for cardiovascular disease, your DNA matters. Genetics can significantly influence your risk for conditions like high blood pressure, high cholesterol, and atherosclerosis, all of which contribute to cardiovascular disease. People with a family history of heart attacks or strokes may inherit a predisposition, even if they live a healthy lifestyle.

Some inherited heart conditions, such as hypertrophic cardiomyopathy or arrhythmogenic right ventricular cardiomyopathy (ARVC), can remain undetected for years. These conditions can increase the risk of sudden cardiac death in young athletes, even if they appear otherwise healthy.

If you have a close relative who developed heart disease at a young age (under 55 for men, under 65 for women), it's worth talking to your doctor about early screening.

2. Silent or Underdiagnosed Risk Factors

Being physically fit doesn’t mean you’re automatically free from other risk factors for cardiovascular disease. 

Some conditions that raise cardiovascular risk often go unnoticed, especially in younger or active people, and can include:

• High blood pressure. Often called the “silent killer,” high blood pressure can quietly damage blood vessels and the heart over time, even in athletes.
  
• High cholesterol. Certain types of cholesterol abnormalities, like elevated lipoprotein(a), may not be included in standard lipid panels but still increase heart disease risk.
  
• Diabetes or insulin resistance. Blood sugar problems may persist under the radar for years, particularly in those who aren’t overweight.
  
• Inflammation. Chronic low-level inflammation, often from stress, sleep deprivation, or autoimmune issues, can contribute to the development of atherosclerosis.
  

Routine checkups and blood tests can help catch these risks early, even if you feel fine.

3. Over-training and Extreme Endurance Exercise

Regular physical activity is good for your heart, but excessive training, especially over long periods, may pose some risks. Studies suggest that extreme endurance athletes, such as marathon runners or long-distance cyclists, can develop certain cardiac changes that may increase risk over time.

Some documented effects of chronic intense exercise include:

• Atrial fibrillation (AFib). An irregular heart rhythm that’s more common in endurance athletes.
  
• Coronary artery calcification. Long-term high-volume exercise may lead to hardened arteries, although these may be more stable and less prone to rupture.
  
• Cardiac remodeling. Repeated stress can cause the heart muscle to thicken or change shape, which may increase the risk of arrhythmias.
  

These effects are relatively rare and often found in athletes with many years of high-intensity training, but they highlight the importance of listening to your body and not pushing through symptoms like dizziness, palpitations, or chest pain.

4. Performance-Enhancing Substances and Supplements

Some physically fit individuals — especially bodybuilders or competitive athletes — may use supplements or performance enhancers that negatively affect the heart, such as:

• Anabolic steroids. Known to increase blood pressure, raise LDL (bad) cholesterol, lower HDL (good) cholesterol, and thicken the heart muscle.
  
• Stimulants. Found in some pre-workout supplements or weight loss products, they can raise heart rate and blood pressure.
  
• Unregulated supplements. Some over-the-counter or imported supplements may contain harmful substances not listed on the label.
  

Even legal, widely available substances can be dangerous in excess or for people with underlying conditions. It’s best to consult a healthcare professional before starting any new supplement, especially if you have heart concerns.

5. Stress, Sleep, and Recovery

Fitness isn’t just about movement; rest and recovery are equally important. Chronic stress, poor sleep, and lack of downtime can increase your cardiovascular risk, no matter how often you exercise.

Here’s how lack of rest and recovery can cause an increased risk of cardiovascular disease:

• Sleep deprivation has been linked to high blood pressure, inflammation, and irregular heart rhythms.
  
• Chronic stress triggers the release of cortisol and adrenaline, which can strain the heart over time.
  
• Inadequate recovery between workouts may lead to systemic inflammation or overtraining syndrome.
  

Physically fit people sometimes push through fatigue or stress in pursuit of performance goals, but true fitness includes rest, sleep, and mental well-being.

6. Misinterpreting Symptoms or Delaying Care

One of the greatest dangers for fit individuals when it comes to cardiovascular disease is assuming “it can’t happen to me.” This mindset may cause someone to ignore or misinterpret warning signs of heart trouble.

Symptoms like chest discomfort, shortness of breath, lightheadedness, or heart palpitations can be brushed off as dehydration, muscle strain, or anxiety, especially after a tough workout, but they could also be signs of something more serious.

If something in your body feels off or just “not right,” it’s always better to err on the side of caution and get it checked out.

How Active People Can Stay Proactive About Heart Health

Physical fitness is still one of the best things you can do for your heart health, but to truly protect yourself, it’s important to think beyond workouts and stay proactive in other areas. 

• Know your numbers. Get regular blood pressure, cholesterol, and blood sugar checks, even if you feel great.
  
• Understand your family history. Talk with relatives and share this information with your healthcare provider.
  
• Pay attention to warning signs. Don’t ignore symptoms that seem unusual or persistent.
  
• Prioritize rest and recovery. Aim for 7–9 hours of sleep, and take rest days seriously.
  
• Use supplements cautiously. Stick to reputable sources and discuss new supplements with your doctor.
  
• Consider screening. If you’re an endurance athlete or have a family history of heart issues, you might benefit from an EKG or echocardiogram.
  

Comprehensive Cardiovascular Care from CardioVascular Health Clinic

Cardiovascular disease can affect even the most physically fit individuals, but understanding your personal risk is the first step toward prevention. With the expertise of the team at CardioVascular Health Clinic, you can gain a better understanding of your risk for cardiovascular disease so you can continue to do the things you love. Through comprehensive care, advanced screening, and individualized treatment plans, we’ll help you protect your heart and preserve your quality of life. No matter your fitness level, taking proactive steps today can make all the difference for your health tomorrow. Schedule a consultation today with our team of cardiovascular experts to get the answers and support you need.

Stay Fit and Informed!

No one can be too fit for heart disease - schedule your cardiovascular screening and get personalize care from CardiovVascular Health Clinic.