Running can help improve your cardiovascular health and keep you fit, but it can also take a toll on your body over time and increase your risk for certain health conditions. Although the research in these areas is still preliminary, some runners take supplements, such as glucosamine and fish oil, to help improve their performance and minimize their risk for any adverse effects. Always speak to your doctor before adding any supplements to your routine to make sure they are safe for you.
Decreased Muscle Soreness
Runners sometimes experience a condition called delayed onset muscle soreness when they are training for long-distance runs. This pain may be due at least in part to inflammation, so supplements that have an anti-inflammatory effect, such as fish oil, may help limit this type of soreness, according to a study published in the "Open Access Journal of Sports Medicine" in 2013.
Glucosamine and Arthritis
Runners also tend to be more likely to suffer from arthritis. A systematic review paper published on the PCOM Physician Assistant Studies Student Scholarship website in 2013 found that taking glucosamine supplements may help delay the need for knee joint replacements in adults who are predisposed to arthritis.
Effect on Physical Performance
Evidence for fish oil improving exercise performance is still preliminary and contradictory. A review article published in "Nutrients" in February 2013 noted that fish oil may improve performance by increasing the amount of oxygen taken up by the muscles. However, most of the beneficial effects observed for fish oil appear to be due to its potential to limit inflammation and the necessary recovery time between bouts of exercise.
Neither of these supplements is safe for everyone. Glucosamine is sometimes made from shellfish, so people with a shellfish allergy should verify the source before using a supplement. It may also make certain conditions worse, including high blood pressure, high cholesterol, asthma and diabetes. Don't use glucosamine if you take blood thinners, diabetes medications or acetaminophen or if you are undergoing chemotherapy. Fish oil may interact with blood thinners, blood pressure medications and birth control pills, and it isn't recommended for people with diabetes, bipolar disorder, depression, HIV/AIDS, high blood pressure or liver disease.