Effects of 12 weeks of high-intensity intermittent training on muscle carnosine concentrations

Author(s)

Vitor de Salles Painelli

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Escola de Educação Física e Esportes (EEFE/BT)
• Defense date: 2017-10-04

Examining board members

Antonio Herbert Lancha Junior; Guilherme Giannini Artioli; Edilamar Menezes de Oliveira

• Advisor: Antonio Herbert Lancha Junior

Abstract

INTRODUCTION: Carnosine is a dipeptide with buffering capacity present within the skeletal muscle, which can be obtained by meat ingestion. Cross-sectional studies report that athletes engaged in high-intensity exercises have a greater muscle carnosine (MCarn) content compared to their untrained counterparts, suggesting that exercise training can modulate MCarn, despite of the absence of longitudinal studies. OBJECTIVE: To investigate the effects of high-intensity intermittent training (HIIT) on CarnM and its associated genes. METHODS: Twenty healthy and vegetarian men (eliminating dietary influences) were matched by maximal oxygen uptake (VO2máx), and randomly assigned to a Control (C, N = 10) or Trained (T, N = 10) group. The T group performed HIIT on cycle ergometer 3 days per week for 12 weeks, with progressive volume (6-12 series) and intensity (140-170% lactate threshold [LT]). The C group kept their usual routine. Prior to the intervention, muscle biopsies were performed for MCarn determination, expression MCarn-related genes and the muscle buffering capacity in vitro (&#946;&#924;invitro). Wingate and VO2máx tests were performed to evaluate total work done (TWD), VO2máx, ventilatory thresholds (VT) and LT. The Mixed Model was conducted for data analysis. RESULTS: An interaction effect was observed for MCarn (F = 4.72, P = 0.04), with significant increases for the T group (Pre: 15.8 ± 5.7 and Post: 20.6 ± 5.0 mmoL.kg-1 dry muscle; +36%; P = 0.01), but not in C (Pre: 14.3 ± 5.3 and Post: 15.0 ± 4.9 mmoL.kg-1 dry muscle; +6.3%, P = 0.99). There was no change in the gene expression of the enzymes and transporters evaluated in the T or C groups. There was an improvement in TWD, VT, LT, VO2máx and &#946;&#924;invitro in the T group (all P<0.05), but no changes in C (P>0.05). CONCLUSION: This study suggests that HIIT can increase MCarn without altering its genes. This increase, associated with &#946;&#924;invitro, may help to explain the potent effect of this type of training on physical and cardiorespiratory fitness (AU)

• FAPESP's process: 13/04806-0 - Effects of 12 weeks of high-intensity intermittent training on intramuscular carnosine concentrations
• Grantee: Vitor de Salles Painelli
• Support Opportunities: Scholarships in Brazil - Doctorate