Can Antibiotics Affect Your Ability To Exercise?

If you're an avid exerciser, you might find that your antibiotic prescription could reduce your motivation to exercise. Although antibiotics are meant to kill bacterial infections, they can also disrupt the microbiome in your gut. Typically, we have trillions of microbes in our body that support our immune system by breaking down key vitamins and amino acids while ridding us of toxic elements (per Harvard T.H. Chan School of Public Health). If we take antibiotics incorrectly, this can disturb the proper balance of microbes in our gut.

This disruption can also affect the system of rewards in our brain. A new study in Behavioural Processes examined the influence of antibiotics on exercise performance and motivation in mice. The researchers gave a 10-day antibiotic treatment to regular mice and "high runner" mice, which were bred to run three times more than regular mice. The regular mice ran slightly faster after the treatment, but the high runner mice ran significantly slower. Both mice ran for less amount of time each day, indicating that the antibiotic treatment affected the reward circuits in the brain.

When both groups of mice recovered for 12 days after the antibiotic treatment, the high running mice didn't return to the running performance they had before the treatment. The study concluded that antibiotics' effects on our microbiome can significantly impact certain aspects of aerobic performance, including motivation and behavior.

The gut-brain connection can explain why our emotions affect our digestive system. When we're stressed, our brain can send signals to our gastrointestinal tract, resulting in pain or nausea (per Harvard Health Publishing). According to Cleveland Clinic, the gut is considered to be a "second brain" because the nerves in our digestive system communicate with our actual brain. These nerves slow down or speed up digestion so that we can respond to any perceived threat in our environment.

Taking antibiotics incorrectly can disrupt the gut-brain connection. According to the Centers for Disease Control and Prevention, antibiotics are critical in treating infections such as strep throat, whooping cough, urinary tract infections, and life-threatening sepsis. If you have a cold or the flu, avoid asking your doctor for an antibiotic. Taking antibiotics when they aren't necessary can result in antibiotic resistance, making you more susceptible to infections.