Whey, branched-chain amino acids (BCAAs), creatine, psyllium husks, caffeine and other non-food items that athletes add to their diet to improve training and recovery. Questions are about which supplements are appropriate in which circumstances, and the details of using them.
There are all sorts of fish oils with different concentrations of EPA + DHA. For example, one soft-gel may be 1000mg of fish oil but contain 180mg of EPA, 120mg of DHA and 700mg of "something else". ...