Before they started exercising on a treadmill, the subjects, 14 male physical active college students, received a beverage containing either 3g of BCAA (2:1:1) + 0.5g Arginine + 12.1g carbohydrates or placebo. Blood samples of each subject were collected before exercise, 0, 10, 20, 40, 60, 120 min and 24 h after exercise and the procedure was repeated after two weeks (cross-over design). The results were as follows:
No significant differences in the levels of lactate, ammonia, creatine kinase and glycerol between the two groups were observed at any of the time points. However, the levels of glucose and insulin were significantly higher in the BA trial as compared to those in the PL trial at the 40 and 60 min recovery points. Furthermore, the testosterone to cortisol ratio at the 120 min recovery point was significantly higher in the BA trial as compared to that in the PL trial.While higher glucose and insulin levels are hardly surprising in view of the fact that the placebo contained no calories whatsoever, the improved hormonal recovery (measured as testosterone / cortisol ratio) in the supplemented group appears to be pretty interesting.
A closer look at the exact data does yet reveal that the supplemented group had a higher testosterone / cortisol ratio to begin with. So, if we calculate the relative changes in the T/C ratio 120min after exercising to exhaustion, these are +13.2% in the placebo group and only +6.8% in the supplemented group.
Does that mean that the money you are spending on preworkout products is wasted? From a hormonal perspective, maybe. From a psychological perspective, we do yet still have another result of the study: "Fatigue score increased immediately at exhaustion in both groups, but the decrease in the fatigue score at 120 min recovery point was significant only in BA trial." Consequently, even if it does not improve the hormonal milieu in the early recovery period, supplementation with branched chain amino acids, arginine and carbohydrates could provide the psychological edge you need to drag yourself to the gym regularly ;-)
On a side note: It would have been interesting to see T/C levels measured beyond the 120 minutes post exhaustion. Based on the fact that the recovery of the T/C levels of the supplemented group sped up from T=60min to T=120min, one may well hypothesize that there would be measurable (hormonal) advantages for the BA group at T=180min and beyond.