The Cooper Institute

Founded in 1970 by the "Father of Aerobics"
Kenneth H. Cooper MD, MPH


Fit vs. Fat: What’s More Important for Women’s Health?

Posted in

Wednesday, Dec 18, 2019

Heart disease is still the leading cause of death among American women.

When it comes to assessing a person’s risk of heart disease, we know that cardio fitness and obesity are both important risk factors to consider. What’s less clear though is which one is a better indicator of risk. Our latest research takes a closer look at whether it is more important for women to improve their fitness or reduce their weight to prevent death from heart disease.

Overlooking Obesity  |  Fit Vs. Fat  |  The Verdict Recommendations

Standard of Measured Fitness 

In 2016, the American Heart Association (AHA) issued a statement calling for measured cardiorespiratory fitness (CRF) as a vital sign in addition to the standard checks for weight, temperature, respiration, pulse rate and blood pressure. Measured fitness has long been the staple of annual preventive care checkups at the Cooper Clinic and is the basis for much of our research at The Cooper Institute.

Long ago, researchers identified smoking, high blood pressure, obesity, diabetes and cholesterol levels as major risk factors for cardiovascular disease (CVD), which includes all diseases of the heart and circulatory system. In recent decades, new evidence has emerged showing that low CRF is strongly associated with all-cause, CVD and cancer mortality. In fact, CRF may be an even stronger predictor of CVD mortality risk on its own than any of the other major risk factors.  

There are many ways to measure or estimate CRF levels. These methods range in complexity and expense from a maximal treadmill exercise test in a laboratory setting to simple, but less accurate, questionnaires. The AHA statement emphasized that all women should undergo a baseline measurement or estimate of CRF. It goes on to suggest that women with low fitness levels should attain at least a moderate level of fitness for optimal health.

Overlooking Obesity 

Most of us dread that moment when the nurse asks us to step up on the scale, and for good reason. Almost 40% of American adults are considered obese, according to the Centers for Disease Control and Prevention (CDC). For Hispanics and African-Americans, that number is closer to 50%. Obesity contributes to a host of chronic conditions such as heart disease, stroke, type 2 diabetes and certain types of cancer - some of the leading causes of preventable, premature death. However, most doctors fear embarrassing patients and therefore tend to overlook or downplay this modifiable risk factor.

Fit vs. Fat 

The study looked at nearly 20,000 generally healthy women around 45 years old who underwent a comprehensive physical exam at the Cooper Clinic. The exam included a maximal treadmill exercise test to measure their cardiorespiratory fitness. Patients were then divided into categories of low, moderate or high fitness based on their age group. 

Researchers also classified women as normal weight or overweight based on a number of different measures of body weight status. These included body mass index, waist circumference, waist-to-height ratio, and percent body fat. The team then looked to see how many women died from CVD almost 20 years later to determine if fitness or obesity was the leading factor.

The Verdict 

The results showed that patients with low or moderate levels of fitness were much more likely to die from CVD than highly fit women. (2.5 times and 1.9 times more likely, respectively).

The results for obesity were similar. As expected, overweight women were almost two times more likely to die from heart disease than normal-weight women, regardless of the method used to determine body weight status. Interestingly though, the study found that fitness seemed to hold more weight as a risk factor for CVD death:

  • Normal-weight women with high fitness had the lowest risk.
  • Normal-weight women with moderate fitness and overweight women with high to moderate fitness had moderate risk.
  • Normal-weight women with low fitness had higher risk.
  • Overweight women with low fitness had the highest risk.   

The conclusion by researchers is that having at least a moderate level of cardio fitness offers some protection from heart disease death for both normal and overweight women.


  1. Get Active:  All women are urged to meet the 2018 Physical Activity Guidelines for Americans (PAGA), which recommends a minimum of 150 minutes each week of moderate-intensity aerobic activity. This can be as simple as a brisk walk for 30 minutes per day, five days per week. Naturally, you will see greater health benefits with more activity and/or higher intensity. Every minute spent taking the stairs, doing household chores, or taking a quick 10-minute walking break at work all count towards the total.  It doesn’t have to be a traditional workout session at the gym, although strength training is recommended at least two days each week in addition to the 150 minutes of physical activity.
  2. Avoid Smoking and Vaping:  The risk of premature death from heart disease can be greatly reduced by avoiding tobacco in all forms, including vaping. While many tout vaping as a safer alternative to smoking, it is still a dangerous and highly addictive habit that can lead to cancer, lung and heart disease.
  3. Check Blood Levels:  Carefully monitoring and controlling blood pressure as well as blood cholesterol, triglyceride, and glucose levels is key to understanding and minimizing your risk of heart attack, heart failure, stroke, and diabetes.
  4. Eat a Heart-Healthy Diet:  The Mediterranean Diet and DASH diet are both heart-healthy, nutrient-rich options to follow (see our list of best and worst diets). For overweight women, losing just 5-10% of body weight can make a big impact towards improving health and reducing the risk of heart disease.

Farrell SW, Barlow CE, Willis BL, Leonard D, Pavlovic A, DeFina L, Haskell WL. Cardiorespiratory fitness, different measures of adiposity and cardiovascular disease mortality risk in women. (2019). J Women’s Health. DOI: 10. 1089/jwh.20199973