Most of us would like to live a long life as long as the latter years are active, meaningful ones and not spent in a nursing home. Scientists still haven’t cracked the longevity code, but from what we know, exercise tops the list of lifestyle habits that keep us healthy and functional. Strength training helps preserve muscle tissue and strength so that you’re more capable of doing the things you enjoy. But what about aerobic, or cardiovascular exercise? Recent studies suggest that being aerobically fit may be key to maximizing lifespan.
What does it mean when we say someone is aerobically fit? Aerobic fitness refers to how efficiently you can deliver oxygen to muscles and tissues when you exercise. To meet the demands of exercise, you breathe in faster to take in more oxygen. That’s the job of your lungs. So, a healthy lung capacity is important for aerobic fitness. If you’re a smoker, your aerobic capacity is reduced because smoking diminishes lung capacity and that, in turn, interferes with the ability to deliver oxygen to tissues.
In addition, your heart plays a major role in how aerobically fit you are. Your heart is what pumps the blood and oxygen to your muscles and tissues. The more efficiently your heart can pump blood, the more oxygen it can drive to working muscles during exercise. Through aerobic training, your heart becomes a stronger pump. The stroke volume or the amount of blood and oxygen carried with each heartbeat goes up. In fact, with regular aerobic exercise, the left ventricle of your heart, the part of the heart that delivers blood to your tissues, becomes slightly thicker. This makes it a more powerful pump and gives it greater ability to better deliver blood and oxygen. At rest, your heart rate is slower when you’re aerobically fit because your heart is a more efficient pump.
Changes also happen peripherally, at the level of your muscles, that improve the ability to tolerate sub-maximal exercise. In response to aerobic training, more capillaries develop around working muscles over time. More capillaries mean more oxygen can be delivered to the muscles you’re working. Inside muscle cells, mitochondria increase in number, giving them the capacity to make more ATP to fuel exercise. So, lots of changes take place during the weeks after you begin training aerobically and they all lead to greater ability to fuel exercise.
Not only does your body tolerate aerobic exercise better and your endurance improve with aerobic training, but good aerobic capacity may be a marker for a lower risk of mortality and greater longevity. In a study, researchers bred rats to have high or low aerobic capacity. When researchers followed them as the aged, they discovered that rats that had higher aerobic capacity outlived the rats with a low tolerance for aerobic exercise by 28 to 45%. They also correlated aerobic capacity with lifespan at all stages of the life of the rats.
Humans are a bit more complex than rats but you find a similar correlation in humans. As research shows, low aerobic capacity is linked with a higher risk of mortality in adults with and without cardiovascular disease.
How Do You Know What Your Aerobic Capacity Is?
You could have your aerobic capacity, or V02 max, measured via a V02 max test. Some universities, hospitals, and fitness centers offer this test. What does it entail? You jump on a treadmill and walk or run as the testers gradually increase the incline. During the test, you wear a mask so that the testers can monitor how much oxygen you’re breathing in and carbon dioxide you’re breathing out. Your oxygen requirements will increase as the exercise becomes more challenging and your body responds by delivering more blood and oxygen to meet those needs. At some point, the intensity is so great that you can’t increase oxygen delivery enough to meet the challenge and oxygen consumption will plateau. The testers use this information to calculate your V02 max or aerobic capacity. You can also approximate your V02 max with a one-mile timed walk test, although this is less accurate. You can find instructions for doing this study at home online.
Having a higher aerobic capacity is one marker of longevity but simply being physically active is too. Studies show that mortality from all causes is reduced by up to 35% in people who are physically active. Sounds sweet, doesn’t it? This isn’t surprising since exercise lowers the risk of the most common causes of premature death, including type 2 diabetes, cardiovascular disease, stroke, and some forms of cancer. In fact, studies that compare the lifespan of athletes versus non-athletes show that being physically active increases lifespan by 0.4 to 6.9 years. That’s significant!
What If you naturally have a low aerobic capacity? If you train aerobically, you can increase your aerobic capacity by as much as 20%. There are a small number of people who get little or no improvement in aerobic capacity in response to aerobic training, however, this is not common. Most people will respond to aerobic training by developing a higher V02 max, which translates into greater exercise endurance and, as studies suggest, possibly greater longevity.
The Bottom Line
Aerobic capacity means you have more endurance and stamina but it may also be a marker of greater longevity. If you look at cultures that live the longest, they’re almost always physically active. Staying active is also the key to good health. Aerobic exercise improves insulin sensitivity and lowers the risk of a variety of chronic diseases. If you want to live long and stay functional longer, make sure you’re training aerobically and doing resistance training. Combine it with a whole food diet and you’re on your way to better health as well!
J Exerc Rehabil. 2016 Feb; 12(1): 37–41. Published online 2016 Feb 1. doi: 10.12965/jer.150261.
Michigan Medicine. University of Michigan. “Aerobic exercise capacity linked to stronger hearts, longer life”
National Cancer Institute. “NIH study finds leisure-time physical activity extends life expectancy as much as 4.5 years”
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