ABSTRACT
Exercise and sport pharmacology pertain to the interaction of exercise and the physiological responses to drugs. Pharmacokinetics concerns the fate of the drug in the body. Pharmacodynamics concerns the response of the body to drugs. Both pharmacokinetics and pharmacodynamics are affected by exercise, usually in an intensity-dependent manner.
When a drug enters the body, only a fraction of it reaches its target. That fraction can vary, as many properly working organ systems come into play, providing a large degree of variation in drug responsiveness in the human population. Many factors contribute to the bioavailability of the drug, such as genetic background, age, percent body fat, and degree of physical fitness. Most drugs are chemically altered and eliminated from the body by diverse mechanisms, which also contribute to the variability seen in human populations. The dose of a drug has to be sufficient to allow enough drug to reach an effective concentration at the site of action. Drugs alter existing physiological pathways, usually by interacting with specific protein receptors. Exercise can change the fate of the drug in the body. As exercise intensity increases, blood is redirected, and rates of metabolism and elimination can change. Since the bioavailability of the drug can change with exercise, the primary or desirable response to the drug can change. The possibility of unwanted side effects can also change. Drugs that have a narrow therapeutic index and are flow-limited during exercise should be monitored closely. In the future, pharmacogenomics may help health providers match subsets of the population with the most effective and safest drug option. The gut microbiome influences human health and is affected by drug treatment and physical activity.
