A Review of the Effects of Chronic Exercise and Physical Fitness Level on Resting Pharmacokinetics Persky AM, Eddington ND, Derendorf H Both acute and chronic exercise induced physiologic changes that can impact the pharmacokinetics of medications. Data on the effects of chronic exercise on the disposition of medications is sparse. Some studies have indicated enhanced absorption of IM-administered medications due to increased capillary density in skeletal muscles. It is unknown whether chronic exercise also increases collateral blood flow to the intestines, thereby increasing drug absorption. Chronic exercise also decreases fat mass and increases fat-free mass, thereby affecting drug distribution. Chronic exercise also alters hepatic metabolism; increased clearance of some medications has been reported. Chronic exercise does not appear to affect renal clearance of medications. Increased aerobic exercise is included in the management of many chronic medications. The authors suggest that additional research is needed on the effect that chronic exercise has on the disposition of medications to anticipate possible altered dosing requirements in these patients. International Journal of Clinical Pharmacology and Therapeutics. 2003;41(11):504-516 Source: MEDSCAPE Journal Scan Pharmacotherapy, January 2004 Contributing Editors: Charlotte A. Kenreigh, PharmD, and Linda Timm Wagner, PharmD Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.