A recent comprehensive study underscores that being aerobically fit is far more critical to longevity than maintaining a low body mass index (BMI), the Washington Post reports.
The findings, published in the British Journal of Sports Medicine, show that being out of shape can double or triple the risk of premature death, irrespective of age or BMI. Conversely, individuals with obesity but high aerobic fitness were about half as likely to die prematurely as those with normal weight but poor fitness.
Led by Siddhartha Angadi, an exercise physiologist at the University of Virginia, the study analyzed data from nearly 400,000 participants across 20 prior studies. Researchers categorized participants into “fit” and “unfit” groups based on objective measures of aerobic fitness, such as cardiovascular stress tests. They then compared these findings with participants’ BMI and mortality rates over follow-up periods of up to two decades.
Key findings include:
- Obesity significantly raises the risk of early death, especially when coupled with poor fitness.
- Individuals with normal weight but low fitness levels were twice as likely to die young as aerobically fit people with obesity.
- Aerobic fitness effectively mitigates mortality risks associated with obesity-related conditions.
“This study confirms that cardiorespiratory fitness is strongly protective against mortality at any BMI,” said Barry Braun, director of the Human Performance Clinical Research Laboratory at Colorado State University.
Encouragingly, the study suggests that improving fitness requires minimal effort. Moving from the bottom 20% of fitness for one’s age to just above this threshold significantly reduces mortality risk. Moderate exercises like brisk walking—defined as activity that allows you to talk but not sing—are sufficient to boost aerobic fitness.
“Rather than focusing on weight loss, prioritize fitness,” said Angadi.
He emphasized that simple activities, such as regular walking, can yield substantial health benefits without the need for drastic lifestyle changes.
The findings challenge conventional notions linking weight directly to health and longevity. While obesity is associated with various chronic conditions, aerobic fitness appears to offer a protective buffer.
John Thyfault, a professor at the University of Kansas Medical Center, stressed that fitness is more important than weight when it comes to mortality risk.
“You can get healthier at your current weight by simply moving more,” he said.
