Nagatomi, R., Tanabe, K., Sakurai, M., Nakajima, Y., Fujimoto, T., Nagamatsu, T., & Hamada, K. (2005). Supplementation of branched-chain amino acids counteracts the reduction in throwing speed of baseball pitchers. Medicine and Science in Sports and Exercise, 37(5), Supplement abstract 1838.

"In a baseball game, pitchers pitch 10 to 20 pitches in an inning, repeating a 5 to 10 minutes break between innings. Pitching speed gradually decreases, but the drop is known to become larger after around 100 pitches. In training camps, [Japan not the USA] however, they commonly pitch more than 100 pitches up to 200 pitches in a continuous manner. Paradoxically, the drop in the pitching speed in the training camp doesn't become abruptly larger after around 100 pitches. In a preliminary experiment, we confirmed such a drop in the pitching speed occurs in a game-simulated pitch with repeated 7 min breaks every 15 pitches as compared to continuous pitches every 20 seconds for 135 pitches. Since we observed a reduction in the branched-chain amino acids (BCAA) concentration in the pitching mode with breaks, we hypothesized BCAA supplementation might counteract the abrupt drop in the pitching speed" (p. S349).

Male baseball pitchers (N = 7) pitched 135 times every 20 seconds in the following conditions, i) with a 7-minute break every 15 pitches with BCAA supplementation drink, ii) with a 7-minute break every 15 pitches with a placebo drink, iii) without breaks and BCAA supplementation drink, and iv) without breaks with placebo. A radar gun measured pitch velocity.

Pitching velocity was significantly reduced at 106-120 pitches with the placebo drink and exaggerated more with breaks than in the placebo condition without breaks. Reduction in pitching velocity was smaller at 106-120 pitches when BCAA supplementation occurred.

Implication. Between innings breaks actually increase fatigue and performance reduction when compared to no breaks. [This justifies the inclusion of active recovery, possibly bullpen throwing, instead of sitting between innings.] Drinking BCAA fluids during the breaks minimizes any reduction in pitching velocity.

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