There’s one reality that we all have to face – the fact that our bodies age. How rapidly it ages has to do with genetics but even more importantly, lifestyle. We’ve all seen people who look ten years older or younger than they actually are and, in many cases, this relates to lifestyle. No doubt about it, your body changes over time. You experience aging most directly at the tissue or organ level but it actually begins at a microscopic level – in the inside of cells.
The Mystery of Aging
Admittedly, we don’t fully understand what causes aging but a variety of theories have been proposed. For one, the aging process is associated with changes in DNA, the genetic blueprint within our cells. It’s DNA that codes for the proteins that tell your body how to function. Over time, DNA accumulates mutations that can change these proteins, how they fold and how they function. At one level, these alterations can impact how tissues and organs carry out their activities.
Independently, changes also occur inside the energy powerhouses of cells called mitochondria. It’s within the mitochondria that ATP, the energy currency that all cells need, is made. Mitochondria have their own DNA and, over time, mitochondrial DNA, and the apparatus that produces ATP can become damaged in the same way nuclear DNA does.
The Role of Oxidative Stress
What causes DNA mutations within cells? One cause is oxidative stress due to free radical formation. Cells are constantly exposed to oxygen and chemicals from the environment and these can damage a cell’s DNA. Fortunately, a healthy lifestyle reduces exposure to toxins. By eating an antioxidant-rich diet, you may be able to prevent some of the DNA damage associated with aging and age-related diseases, like cancer.
When you think about slowing the cellular aging process, don’t forget about exercise. What type of exercise? A recent study showed that high-intensity interval training may help cells offset some of the damage that goes along with aging. How do we know this? Researchers asked two groups of healthy men and women to adopt exercise programs. One group of participants, the young adults, were between the ages of 18 and 30. The other group was older, between the age of 65 and 80. Some of the participants did high-intensity interval training, a second groups weight trained only, while the third did both forms of training for 12 weeks. A control group did no exercise.
What the Study Showed
Upon completion of the study, the researchers looked at all of the participants’ muscle cells via muscle biopsies. Of the three groups, the muscle cells of the group that did high-intensity training showed the most profound changes. The younger participants experienced a 49% boost in mitochondrial function, while the older participants enjoyed a whopping 69% improvement in mitochondrial capacity. Since we know mitochondria are involved in cellular aging, enhancing their function could slow or even reverse aging at the cellular level. Who wouldn’t want that?
We also know that endurance exercise boosts a cell’s ability to produce ATP, the high-energy compound that all cells require. In response to endurance exercise, cells produce more mitochondria, a process called mitochondrial biogenesis. In addition, the machinery used to produce energy within the mitochondria is upgraded. For example, training boosts the enzymes involved in mitochondrial ATP production. However, high-intensity interval training gets the job done in a faster, more efficient manner.
Insulin Sensitivity and Inflammation
In this study, researchers also found that high-intensity interval training improved insulin sensitivity. That’s not surprising since people who are insulin resistant typically have poorly functioning mitochondria, and high-intensity exercise enhances mitochondrial function. Insulin resistance is also a factor in aging because insulin resistance and chronic inflammation are closely intertwined. Why is this important?
Inflammation is a factor in a number of age-related diseases and damages tissues in a way that prematurely ages them. Although chronic inflammation often precedes insulin resistance, insulin resistance appears to worsen chronic inflammation as well. Anything you can do to fight insulin resistance bodes well for aging. High-intensity exercise is one way to do that.
Another way high-intensity interval training may slow aging and the onset of age-related diseases is by helping with visceral abdominal fat loss, a type of deep belly fat linked with chronic health problems and insulin resistance. According to some studies, high-intensity exercise is more effective at whittling away visceral fat than moderate-intensity exercise like brisk walking, jogging, or cycling at a moderate pace.
Impact on Muscle Proteins
Also, in the study, the group that did high-intensity training experienced enhancements in proteins needed for building new muscle tissue. So, high-intensity interval training, when combined with resistance training, could give you a leg up on building muscle tissue as well. If you’re trying to build or at least preserve muscle tissue, high-intensity interval training is your best bet, combined with resistance training, of course. Doing a vigorous interval workout improves aerobic and anaerobic capacity, offering similar or better cardiovascular benefits than moderate-intensity exercise.
One problem with moderate-intensity exercise is it takes longer to do. In addition, sustained periods of cardiovascular exercise may boost the release of cortisol, a catabolic hormone that breaks down muscle tissue. Although you get the release of cortisol with a high-intensity workout, you get a greater release of anabolic hormones, like growth hormone. This helps balance the effect of cortisol, making muscle loss less of an issue. During high-intensity exercise, you also recruit more fast-twitch muscle fibers, which helps build muscle power. You can enhance this effect by doing power exercises during the active intervals, such as plyometric moves or kettlebell swings where you’re generating force quickly.
The Bottom Line
You have to love high-intensity interval training because it’s so time efficient and effective – but there’s another reason to embrace it. High-intensity exercise may help you fight the aging process at the cellular level. Make sure it’s part of your routine.
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