Post-exercise branched chain amino acid supplementation does not affect recovery markers following three consecutive high intensity resistance training bouts compared to carbohydrate supplementation

Abstract

Background: Amino acid supplementation has been shown to potentially reduced exercise-induced muscle soreness. Thus, the purpose of this study was to examine if branched chain amino acid and carbohydrate (BCAACHO) versus carbohydrate-only sports drink (CHO) supplementation attenuated markers of muscle damage while preserving performance markers following 3 days of intense weight training.

Methods: Healthy resistance-trained males (n = 30) performed preliminary testing (T1) whereby they: 1) donated a baseline blood draw, 2) performed knee extensor dynamometry to obtain peak quadriceps isometric and isokinetic torque as well as electromyography (EMG) activity at 60°/s and 120°/s, and 3) performed a one repetition maximum (1RM) barbell back squat. The following week participants performed 10 sets x 5 repetitions at 80 % of their 1RM barbell back squat for 3 consecutive days and 48 h following the third lifting bout participants returned for (T2) testing whereby they repeated the T1 battery. Immediately following and 24 h after the three lifting bouts, participants were randomly assigned to consume one of two commercial products in 600 mL of tap water: 1) BCAAs and CHO (3 g/d L-leucine, 1 g/d L-isoleucine and 2 g/d L-valine with 2 g of CHO; n = 15), or 2) 42 g of CHO only (n = 15). Additionally, venous blood was drawn 24 h following the first and second lifting bouts and 48 h following the third bout to assess serum myoglobin concentrations, and a visual analog scale was utilized prior, during, and after the 3-d protocol to measure subjective perceptions of muscular soreness.

Results: There were similar decrements in 1RM squat strength and isokinetic peak torque measures in the BCAA-CHO and CHO groups. Serum myoglobin concentrations (p = 0.027) and perceived muscle soreness (p < 0.001) increased over the intervention regardless of supplementation. A group*time interaction was observed for monocyte percentages (p = 0.01) whereby BCAA-CHO supplementation attenuated increases in this variable over the duration of the protocol compared to CHO supplementation.

Conclusion: BCAA-CHO supplementation did not reduce decrements in lower body strength or improve select markers of muscle damage/soreness compared to CHO supplementation over three consecutive days of intense lower-body training.

Keywords: Branched chain amino acids; Immune system; Muscle damage; Resistance training.

Fig. 1

Study design. Abbreviations: USG, urine specific gravity; VAS, visual analog scale; EMG, electromyography; 1RM, one repetition maximum

Fig. 2

T1 and T2 squat and isometric peak torque values. No main time effect or group*time interaction was observed for 1RM squat (panel a). A main time effect was observed for isometric peak torque (panel d), and dependent t-tests revealed a significant decrease in the variable in the CHO group (p ≤ 0.001), while there was no decrease in the BCAA-CHO group (p = 0.08). Individual responses are plotted for squats (panel b and c) and isometric torque (panel e and f). Abbreviations: BCAA-CHO, branched-chain amino acid and carbohydrate-supplemented group; CHO, carbohydrate only-supplemented group

Fig. 3

T1 and T2 isokinetic torque and EMG activity. A main time effect was observed for peak torque at 60°/s (p ≤ 0.001), and further analysis revealed T1-to-T2 decreases in the CHO (p = 0.001) and BCAA-CHO (p = 0.013) groups (panel a). A main time effect was observed for isokinetic mean EMG activity at 60°/s (p = 0.025), but no significant differences were observed within the CHO (p = 0.12) or BCAA-CHO (p = 0.087) groups (panel b). No main time effect or group*time interaction was observed for isokinetic peak EMG at 60°/s (panel c). There was a main time effect for isokinetic peak torque at 120°/s (p = 0.021), but further analysis revealed that this variable did not decrease in the CHO (p = 0.074) and did decrease in the BCAA-CHO (p = 0.047) group (panel d). There was a main time effect for isokinetic mean EMG 120°/s (p = 0.007), and further analysis revealed T1-to-T2 decreases in the CHO (p = 0.037) but not BCAA-CHO (p = 0.095) group (panel e). There was a main time effect for isokinetic peak EMG at 120°/s (p = 0.007), but further analysis revealed T1-to-T2 decreases did not occur in the CHO (p = 0.063) or BCAA-CHO (p = 0.060) groups (panel f). Abbreviations: BCAA-CHO, branched-chain amino acid and carbohydrate-supplemented group; CHO, carbohydrate only-supplemented group

Fig. 4

Serum myoglobin, perceived soreness, and training volume throughout the study. A main time effect was observed for myoglobin (p = 0.027), but pairwise comparisons (both groups collapsed over time) only revealed a tendency for this value to increase at T2 relative to T1 (p = 0.055) (panel a). A main time effect was observed for perceived soreness (p ≤ 0.001), and pairwise comparisons revealed increases 24 h post-bout 1 (p ≤ 0.001), 24 h post bout 2 (p ≤ 0.001), and 48 h post bout 3 (p ≤ 0.001) relative to T1 (panel b). There was a main time effect for total lifting volume (p ≤ 0.001), and pairwise comparisons revealed decreases at bout 2 (p ≤ 0.001) and bout 3 (p ≤ 0.001) relative to bout 1 (panel c). Abbreviations: BCAA-CHO, branched-chain amino acid and carbohydrate-supplemented group; CHO, carbohydrate only-supplemented group