It sort of serves the same purpose as GW for endurance athletes but it's not as effective. It's really expensive for what you get out of it. There are better options like gw or even epo. The only time aicar trumps them is when the athlete is tested. Aicar is really hard to test for and as far as I know has not had a single positive anti doping Test. For every other scenario, the juice ain't worth the squeeze.