title: Exercise training and Beta-alanine-induced muscle carnosine loading.
abstract: OBJECTIVE
  Beta-alanine (BA) supplementation has been shown to augment muscle carnosine concentration, thereby promoting high-intensity (HI) exercise performance. Trained muscles of athletes have a higher increase in carnosine concentration after BA supplementation compared to untrained muscles, but it remains to be determined whether this is due to an accumulation of acute exercise effects or to chronic adaptations from prior training. The aim of the present study was to investigate whether high-volume (HV) and/or HI exercise can improve BA-induced carnosine loading in untrained subjects.
  
  
  METHODS
  All participants (n = 28) were supplemented with 6.4 g/day of BA for 23 days. The subjects were allocated to a control group, HV, or HI training group. During the BA supplementation period, the training groups performed nine exercise sessions, consisting of either 75-90 min continuous cycling at 35-45% Wmax (HV) or 3 to 5 repeats of 30 s cycling at 165% Wmax with 4 min recovery (HI). Carnosine content was measured in soleus and gastrocnemius medialis by proton magnetic resonance spectroscopy.
  
  
  RESULTS
  There was no difference in absolute increase in carnosine content between the groups in soleus and gastrocnemius muscle. For the average muscle carnosine content, a higher absolute increase was found in HV (+2.95 mM; P = 0.046) and HI (+3.26 mM; P = 0.028) group compared to the control group (+1.91 mM). However, there was no additional difference between the HV and HI training group.
  
  
  CONCLUSIONS
  HV and HI exercise training showed no significant difference on BA-induced muscle carnosine loading in soleus and gastrocnemius muscle. It can be suggested that there can be a small cumulative effect of exercise on BA supplementation efficiency, although differences did not reach significance on individual muscle level.
authors.affiliation: Department of Movement and Sports Sciences, Ghent University , Ghent , Belgium.
authors.forename: Tine
authors.initials: T
authors.lastname: Bex
authors.affiliation: Department of Movement and Sports Sciences, Ghent University , Ghent , Belgium.
authors.forename: Weiliang
authors.initials: W
authors.lastname: Chung
authors.affiliation: Department of Movement and Sports Sciences, Ghent University , Ghent , Belgium.
authors.forename: Audrey
authors.initials: A
authors.lastname: Baguet
authors.affiliation: Department of Radiology, Ghent Institute for Functional and Metabolic Imaging, Ghent University , Ghent , Belgium.
authors.forename: Eric
authors.initials: E
authors.lastname: Achten
authors.affiliation: Department of Movement and Sports Sciences, Ghent University , Ghent , Belgium.
authors.forename: Wim
authors.initials: W
authors.lastname: Derave
keywords: beta-alanine; carnosine loading; muscle contractions; sport supplements; training