Over a period of 6 weeks the researchers supplemented a group of 36 judoists with either 600 mg EPA and 400 mg DHA per day or the same amount of long chain polyunsaturated fatty [LCPUFA] acids plus 30 mg vitamin E, 60 mg vitamin C and 6 mg β-carotene and measured resting and exercise-induced lipid peroxidation in their subjects. Here are the results:
At T (1) [before supplementation], there were no significant differences among treatment groups with respect to lipid peroxidation, lag phase, and levels of α-tocopherol or retinol. The consumption of an n-3 LC PUFA supplement increased oxidative stress at rest and did not attenuate the exercise-induced oxidative stress. The addition of antioxidants did not prevent the formation of oxidation products at rest. On the contrary, it seems that the combination of antioxidants added to the n-3 LCPUFA supplement led to a decrease in, CD(max) [conjugated dienes], R (max) [maximum rate of oxidation], and POOL [lipoperoxide ] and MDA [malondialdehyde] concentrations after a judo training session.So, in a way LCPUFA work like "exercise in a pill": At rest, they increase similar stressors as exercise does. This holds true regardless of additional anti-oxidant supplementation. When you exercise, however, a combination of LCPUFA + antioxidants appears to provide some protection from exercise induced stressors, so that overall, athletes would probably benefit from LCPUFA + antioxidants consumption.
Notice, I purposefully wrote "consumption" and not "supplementation", because let's be honest: If we have a look at the combination of nutrients a natural diet would provide, you always get your LCPUFAs with adequate amounts of antioxidants. So, keeping or switching to a healthy diet should still be your priority - if you then still see the need for additional supplementation, you may want to give a quality fish oil and some vitamins a try.