Health, Exercise, and Sports Sciences ETDs

Publication Date

7-1-2016

Abstract

Purpose: To investigate: 1) if branched-chain amino acid supplementation (BCAA) enhances recovery from acute, eccentric resistance exercise as measured by indirect markers of muscle damage, and 2) the impact of acute, eccentric resistance exercise on markers of autophagy and heat shock protein during recovery. Methods: Twenty resistance-trained males were randomly assigned to eight days of BCAA or PLCB and adhered to a diet consisting of 1.2 g/kg/d protein. On day five, all subjects completed 10x8 eccentric squats at 70% one repetition maximum (1RM), followed by 5x20 split jumps. Plasma creatine kinase (CK), erythrocyte glutathione, vertical jump (VJ), maximal voluntary isometric contraction (MVIC), jump squat (JS), perceived soreness were measured as indirect markers of muscle damage. Autophagy (LC3-I, LC3-II, p62) and heat shock protein (HSP70) responses were assessed via peripheral blood mononuclear cells. Variables were measured immediately before, immediately post (IPE), as well as 1, 2, 4, 24, 48, and 72 hours (hr) post-exercise. Results: Plasma CK levels were significantly lower for the BCAA group at 48 hr post-exercise; however, no significant group-by-time effect was detected. Erythrocyte glutathione (GSSG/tGSH) was significantly elevated 1, 2, and 4 hr in both BCAA and PLCB groups compared to pre-exercise; however, no significant group-by-time effect was detected at any time-point. The BCAA group reported significantly less soreness compared to PLCB at 48 and 72 hr post-exercise. MVIC was significantly higher for the BCAA group at 24 hr post-exercise, but no significant group-by-time effect was observed. No significant difference between groups was detected for VJ or JS. No differences between groups were detected for protein expression of LC3-II, LC3 II/ I, p62, or HSP70 at any time-point. When combining groups, LC3-II decreased significantly 2 and 4 hr post-exercise. p62 decreased significantly IPE, 2, and 4 hr post-exercise and significantly increased 24 hr post-exercise. HSP70 significantly increased 48 and 72 hr post-exercise. Conclusions: BCAA may mitigate soreness following muscle damaging exercise; however, when consumed with a diet adequate in protein, the attenuation of performance decrements or corresponding CK levels are modest. These data support previous work suggesting that the heat shock response exerts regulatory control over autophagy.

Keywords

eccentric, BCAA, autophagy, heat shock protein, recovery

Document Type

Dissertation

Language

English

Degree Name

Physical Education, Sports and Exercise Science

Level of Degree

Doctoral

Department Name

Health, Exercise, and Sports Sciences

First Committee Member (Chair)

Kravitz, Len

Second Committee Member

Dokladny, Karol

Third Committee Member

Kerksick, Chad

Fourth Committee Member

Vaughan, Roger

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