Scientists are always looking for new ways to slow the aging process. Unfortunately, we’re not even 100% sure what causes us to age. A number of theories pertaining to aging exist. One is the idea that oxidative stress damages components of a cell and causes them to function differently. However, focus is now shifting to the tiny organelles that produce energy inside each of your cells. These organelles, known as mitochondria, spend their existence turning macronutrients from the foods you eat into ATP, the energy currency that drives everything from cellular function to muscle contractions.
The most current theory about aging is that oxidative stress originates within the mitochondria. Remember, mitochondria need oxygen to make energy and this increases free radical production. As free radicals form over time, the mitochondria become damaged and, eventually, crippled. As such, they no longer supply the energy needs of cells as efficiently. No wonder people become less energetic with age! As ATP production declines, cells that use the most energy experience are affected the most, especially heart cells and brain cells. The heart becomes a weaker pump and brain cells lose their ability to communicate as efficiently.
Mitochondria even have their own genetic material, or DNA. They use this DNA to make proteins that support cellular functions. Interestingly, the DNA inside your mitochondria are inherited only from your mother. So, if you have good mitochondria DNA, thank your mom! A mitochondria’s DNA can also be damaged by oxidative stress and free radicals. However, over the years, even healthy mitochondria develop mutations, or changes in their DNA, that negatively impact their function. Some of these changes can trigger inflammation, another process that contributes to aging. Are there things we can do to slow down this process?
Can High-Intensity Exercise Slow Cellular Aging?
We know that HIIT training is ideal for trimming waistlines and improving stamina, but can it also slow cellular aging? A study funded by the National Institutes of Health looked at this issue. They recruited male and female volunteers, some young, under the age of 30, and another group between the ages of 65 and 80. They asked the participants to take part in two types of exercising training programs for 3 months. One exercise program consisted of days of low-intensity exercise and moderate-intensity exercise on a treadmill. They also did high-intensity exercise sessions in-between. The second group engaged in strength training twice a week. Finally, a third group combined moderate-intensity exercise with weight training.
The good news is all of the groups improved their fitness level. The strength training group was the group that made the most strength and muscle mass gains. But, it was the high-intensity interval training group that experienced the greatest improvements in mitochondrial function. In fact, their mitochondrial capacity improved by a whopping 49%. Along with these changes, the participants enjoyed greater improvements in insulin sensitivity than the other groups, suggesting that high-intensity interval training may be best for improving metabolic health. Insulin sensitivity declines with age and that’s one reason why age-related diseases, like type 2 diabetes and heart disease become more common as we get older.
Why Might HIIT Training Be Beneficial to Cells?
In the study, researchers biopsied the muscles of each participant. What they found was the group that did high-intensity training had higher levels of proteins within their mitochondria. HIIT training seemed to boost the ability of mitochondria to produce cellular proteins. The muscles themselves had a higher density of proteins. This may give the muscles greater ability to maintain their size. It’s no secret that we lose muscle strength and mass with age and it’s important to preserve muscle size and function through good nutrition and strength training.
How Strong is the Link Between Mitochondria and Aging?
Interestingly, scientists at Newcastle University discovered that removing the mitochondria from cells rejuvenates the cell and makes it behave like a younger cell. By eliminating the damaged mitochondria, it gives aged cells a new lease on life. This further supports the theory that mitochondrial aging and damaging contribute to cellular aging, which, in turn, plays a role in whole organism aging. Although there lots more to learn about mitochondrial aging and the aging process itself, there’s little doubt that aging begins at the cellular level.
The Bottom Line
Now, you have another reason to add high-intensity exercise to your routine. By boosting mitochondrial function, vigorous sweat sessions may slow cellular aging. Exercise ramps up your body’s internal antioxidant defense system as well, giving cells extra protection against oxidative damage Until we know more, keep working out and include antioxidant-rich fruits and vegetables in your diet to give your cells greater resilience in the face of oxidative damage. In an imperfect world, you can’t avoid cell damage but a healthy lifestyle, including high-intensity training, may help your body mitigate some of the effects of cellular aging.
CNN. “Interval Training Exercise Could Be a Fountain of Youth”
Biochim Biophys Acta. 2015 Nov; 1847(11): 1347–1353.doi: 10.1016/j.bbabio.2015.05.022.
J Clin Invest. 2013 Mar 1; 123(3): 951–957.
Biochim Biophys Acta. 2015 Nov; 1847(11): 1347–1353. doi: 10.1016/j.bbabio.2015.05.022. Published online 2013 Mar 1. doi: 10.1172/JCI64125.
Science Daily. “Mitochondria shown to trigger cell aging”