Shawn Radcliffe is a science writer who received a B.A. in writing and a B.S. in biological sciences from the University of Pittsburgh, and a master's in Science Education from Drexel University.
Medical review by Marvin Singh, M.D.
Dr. Marvin Singh is an Integrative Gastroenterologist in San Diego, California. He is trained and board certified in Internal Medicine and Gastroenterology/Hepatology.
If you think feeling tired and rundown as you get older is something you just have to live with, think again. There are many steps you can take that can boost your energy level, such as eating and sleeping better.
One of the reasons we lose energy as we age: declining mitochondrial health.
Mitochondria are known as the powerhouses of the cells. They use oxygen to convert food energy into adenosine triphosphate (ATP), which stores that energy as chemical bonds. ATP is used throughout the body to keep things running. When mitochondria stop working properly, ATP production decreases. That leaves your cells with an energy deficit and you feeling fatigued. Mitochondrial dysfunction is common during aging and contributes to almost all chronic health conditions.
These changes are driven in part by oxidative damage to the mitochondrial membranes. This can be caused by pollution, tobacco use, high-fat/high-sugar diets, and other stressors. The level of NAD+ also decreases as you age. This coenzyme is needed by mitochondria to make ATP, so less NAD+ means less energy.
Other factors that can make us feel tired as we age:
There are a lot of reasons you lose energy as you age, and if it starts interfering with your daily life, you should see a doctor.
1. Hormonal changes
The level of certain hormones decreases as we age, including estrogen in women, testosterone in men, melatonin, and thyroid hormones. Some of these help us sleep or keep our energy level and mood elevated. "Changes in hormones can leave us sleepless, foggy, and tired," says Eudene Harry, M.D., medical director for Oasis Wellness and Rejuvenation Center in Orlando, Florida.
In men, a significant drop in testosterone levels can cause a reduced sex drive, decreased motivation, and difficulty sleeping, says Niket Sonpal, M.D., a New York City–based internist and gastroenterologist. These symptoms can also cause low energy and physical or mental fatigue.
2. Lack of quality sleep
A third of American adults report that they get less than the recommended seven to nine hours of sleep a night. "Lack of sleep not only decreases our energy levels the next day," says Harry, "but it also increases inflammation, which can certainly deplete our energy in the long run."
As you get older, you may also find yourself chasing a good night's sleep. As we get older, our circadian rhythm can be disrupted, says Sonpal. This causes us to go to sleep earlier and wake earlier, which means less time in deep sleep—and less deep sleep to replenish your energy levels.
3. Diet and lifestyle
Eating healthy is one of the easiest ways to boost your energy levels, because foods provide the macro- and micronutrients needed to power your cells. Yet in 2015 less than 14% of Americans over 40 ate the recommended number of servings of fruit each day. For vegetable intake, it was worse—less than 11% hit this target.
Harry says that as we get older, our ability to absorb certain nutrients from our food can also decrease, such as vitamin B12, which is needed to convert food into energy. Vitamin B12 deficiency is common among older adults, but vegans and vegetarians who don't take B12 supplements are also at risk.
In addition to eating healthy, physical activity "can go a long way to [keeping] us vibrant and energetic as we get older," says Harry. However, in 2015 only about 23% of adults ages 18 to 64 got enough aerobic and strengthening exercise each week.
Why nicotinamide riboside is the best supplement to support healthy aging.*
There's no one product that will be able to address all causes of fatigue, but you can target one major cause, specifically: mitochondrial function.*
To keep your mitochondria functioning properly, a supplement such as nicotinamide riboside (NR) might help.* This precursor to NAD+ is found in trace amounts in milk and yeast-containing food products. It is also available as a supplement.
Cellular beauty has arrived with this revolutionary formula.*
Research shows that NR supplements can support NAD+ levels.* NAD+ is needed by the mitochondria to function properly. It also supports the activity of a protein called SIRT1, which is involved in the formation of new mitochondria.*
Other NAD+ precursors are available in food and supplements. However, one study found that NR is more bioavailable than some other precursors.* It is also well-tolerated and doesn't cause flushing.
The bottom line:
Keep in mind that fatigue can have many causes, including some that are serious. If you often feel tired and rundown, you should see a doctor to rule out any medical conditions that may be draining your energy. From there, you can make lifestyle and dietary changes, as well as adding a healthy aging supplement.