Many active adults sip a BCAA powder mixed into water during their workout. Depending on your reason for using this popular supplement, a study published in The Journal of Sports Medicine and Physical Fitness has an interesting suggestion for BCAA timing.
Fifteen men in their early 20s consumed 9.6 grams of BCAAs 3 days before and 3 days after performing 30 eccentric reps with their non-dominant arm. Some supplemented with BCAAs before the workout, and some supplemented afterward.
Blood levels of BCAAs increased significantly more during recovery in subjects supplementing before training compared to subjects who supplemented post-workout. Those supplementing with BCAAs pre-workout also reported less delayed onset muscle soreness than subjects who supplemented with BCAAs post-workout.