Physical activity is not about gym mirror selfies or a flexed bicep. The benefits of exercise are often conflated with an aesthetic, and exercise itself conflated with vanity. The reality is exercise itself — moving heavy objects that challenge your body and/or moving your body with an elevated heart rate — confer numerous benefits that help you achieve a long, healthy life. The irony is the obsessive pursuit of a “shredded” physique can negate the benefits and even have the opposite effect. Keep reading to learn how regular exercise that is appropriately challenging to your fitness level can improve health and longevity.
Exercise reduces stress
It’s not just the escape exercise provides from the stressors of daily life; the runner’s high is real. When you exercise, your body releases endorphins, which elevate your mood, help you relax, and reduce tension in the muscles (which may seem counterintuitive after a tough training session). Endorphins also contribute to lowering the stress hormone cortisol which, when chronically elevated due to ongoing stress, can have negative effects on health.
While cortisol spikes immediately after exercise as part of the body’s normal stress response, regular exercise can keep levels of the hormone in check by training the body to better manage stress without constant cortisol release. Exercise also increases production of dopamine and serotonin, which contribute to better mood.
Exercise improves sleep
When your head is on the pillow and your body is relaxed and your brain isn’t racing, it’s easier to fall and stay asleep. In addition to reducing stress and improving relaxation, exercise helps regulate circadian rhythm to support a healthy sleep-wake cycle. By increasing body temperature and releasing hormones, exercise promotes wakefulness during daytime and helps you fall asleep at the appropriate time at night. If you exercise outdoors during daylight, the benefits to sleep can compound with increased Vitamin D synthesis.
Exercise improves metabolism
Yes, we said this wasn’t about body composition and it’s still not, in a purely aesthetic sense. However, maintaining higher muscle mass helps you burn more calories at rest, which supports lower body fat, mitigating the health risks that come with it. Muscle loss is tied to numerous diseases of aging and grip strength often indicates longevity. Because exercise pushes glucose (sugar that is the end result of carbohydrate consumption) into the working muscles, less glucose stays in the bloodstream, increasing insulin sensitivity to reduce risk of diabetes.
Exercise also improves the function of mitochondria, the engines of the cells where food is converted to energy. By increasing the use of metabolic nutrients like Vitamins C and B12 as well as supporting better mitochrondial performance, exercise helps your body better use food for energy instead of depositing it as fat.
Exercise supports life-long brain health
While sleep and stress management help keep your brain healthy, exercise in and of itself contributes to better cognitive function and memory by increasing healthy brain cells and neurotransmitters. Exercise increases blood flow to the brain, stimulating neuron (brain cell) production and health by providing better delivery of oxygen and nutrients.
Hormones released during exercise further promote growth and health of these cells. Some studies indicate these increases in brain cells are so profound that areas of the brain where learning and memory take place may actually enlarge. Some studies have linked exercise to lower risk of dementia, possibly due to physical activity’s reduction of inflammation linked to cognitive decline.
Exercise improves gut health
Here’s one you may have never heard before: exercise can improve digestion. Part of the reason includes something you may have heard before: stress can impair digestion. Along with the reduction in stress and stress hormones, regular exercise helps the muscles in the digestive tract move food with more efficiency, reducing constipation. And, getting even more obscure, exercise increases gut bacteria diversity, which is critical not just for digestion, but immune system and metabolic health. A diverse gut microbiome coupled with physical activity increases in blood flow to the digestive system and improves absorption of critical nutrients so your immune and metabolic systems have more fuel.
Exercise helps the immune system
Speaking of the immune system, we’ve already covered how exercise reduces stress, improves sleep, and supports gut health — all of which make the immune system work better. Your regular workouts are also responsible for reducing inflammation and oxidative stress (the latter by increasing antioxidant activity) that are breeding grounds for some of the most deadly noncommunicable diseases. Like in the brain, exercise increases cell production in the immune system, building your body’s defense against infections, cancer cells, and viruses. Increases in circulation help these cells travel to areas of the body under attack.
Similarly, exercise stimulates response of antibodies that fight off pathogens. Of course, the above statements pertain to normal exercise performed on a regular basis with proper recovery. Overtraining can have the opposite effect on immune system health. And, while maintaining a workout regimen over time strengthens the immune system, intense exercise sessions can temporarily lower immune response. So, while your active lifestyle can help avoid catching the cold and mitigating the severity, hitting the gym when you feel one coming on may exacerbate it.
Exercise increases longevity
One of the better indicators of how well your body is aging is the length of its telomeres, the caps that protect the ends of each chromosome. Shorter telomeres indicate cell damage and disease. While all telomeres shorten with age, regular exercise can slow the process and help maintain health for longer by increasing the activity of an enzyme responsible for lengthening telomeres, supporting DNA repair, and reducing oxidative stress. There may be no better indicator of getting old and infirm than a broken hip. The damage is due not to the fall itself, but the brittle bones of older age. Exercise, particularly resistance training, decreases fracture risk by increasing bone density via enhanced calcium absorption, release of growth hormone, and stimulation of bone-building cells to make more tissue. And, if you’re training balance and coordination in your sessions, you mitigate the risk off toppling over in the first place.
Exercise can also reduce your risk of the biggest killer in the United States, cardiovascular disease. There's a reason so many workouts are labeled “cardio”; they strengthen your heart by training it to be more efficient at pumping blood. The increases in blood flow and oxygen/nutrient circulation throughout the body help prevent clots and blockages, which can cause strokes.
Coming in second to heart disease on the biggest killers list is cancer. Exercise helps you avoid obesity, inflammation, and oxidative stress — all of which make you more vulnerable to cancer as well as heart disease and just about every other ailment — and decreases hormones that, when elevated, have been linked to cancer. Indeed, strong evidence indicates physical activity lowers risk of developing colon, breast, kidney, liver, endometrial, throat, and stomach cancer.
