Yerba mate’s unique blend of bioactive compounds, like antioxidants and caffeine, have made it a candidate as a potential ergogenic aid. While yerba mate seems to influence the body’s ability to turn fat into energy during exercise, its effects on exercise performance and recovery require more research.
Consuming yerba mate capsules an hour before exercise seems to consistently increase fat oxidation during submaximal (<70% VO2max) exercise in active men and women.[1][2][3] However, current research has reported little to no benefit on overall exercise performance. While one randomized controlled trial (RCT) in trained male cyclists reported minor increases in performance and power output,[2] several other RCTs in active individuals failed to find any effect on perceived exertion, muscle strength, or power output.[1][4][5][3] The caffeine content of the yerba mate in all the studies was below what is generally considered an ergogenic dose.[6]
Interestingly, one study in men reported that yerba mate tea taken for a week before an exercise test enhanced strength recovery 24 hours after eccentric exercise (but not after 48 or 72 hours). This effect was proposed to be due to the antioxidant effect of yerba mate and was accompanied by increased plasma levels of glutathione and polyphenols before and after exercise.[5]