We all know that exercise is supposed to be good for us, but only about 20 percent of people move regularly. Those of us who exercise may be drawn into popular workout trends. However it is possible that overly aggressive high-intensity interval training (HIIT) or chronic cardio may not be the smartest way to look and feel our best.
When you don’t exercise enough, it can harm your immune system, reduce your stress resilience, and deregulate your circadian rhythm. However when you do exercise too much for too long, too intensely, too frequently, and without sufficient recovery, you may cause problems to your stress-response system, leading to immune problems, injury, and a leaky gut.
Over-exercising leads to an increase of the Cortisol hormone levels which rise with rigorous exercise, such as running, which may cause too much wear and tear and accelerate aging.
High cortisol also reduces gut motility, blocks digestion, blunts blood flow to the gut, and lessens mucus production, an important immune function.
To sum it up, like many things when it comes to health, exercise has a U-shaped association, meaning that moderate amounts are optimal but low or high levels can be harmful. The general recommendation is to exercise 20 to 30 minutes per day four times per week.