[adamdusty]

At least it's getting studied. Most fitness supplements are total garbage advertised by equally garbage people trying to make money risking other people's health.

The paper pretty much says fish oil + exercise does not increase performance ("inconclusive") and some evidence for improved fat loss. Many of the studies reviewed by the paper show evidence that heart rate is lower during "submaximal" exertion.

GP links to a list of "certified" fish oil sources, so if you wanted to at minimum test for yourself, you could just pick one from the list before you pursue your fish oil PhD.