title: Effects of beta-alanine supplementation and interval training on physiological determinants of severe exercise performance.
abstract: BACKGROUND
  We aimed to manipulate physiological determinants of severe exercise performance. We hypothesized that (1) beta-alanine supplementation would increase intramuscular carnosine and buffering capacity and dampen acidosis during severe cycling, (2) that high-intensity interval training (HIT) would enhance aerobic energy contribution during severe cycling, and (3) that HIT preceded by beta-alanine supplementation would have greater benefits.
  
  
  METHODS
  Sixteen active men performed incremental cycling tests and 90-s severe (110 % peak power) cycling tests at three time points: before and after oral supplementation with either beta-alanine or placebo, and after an 11-days HIT block (9 sessions, 4 × 4 min), which followed supplementation. Carnosine was assessed via MR spectroscopy. Energy contribution during 90-s severe cycling was estimated from the O2 deficit. Biopsies from m. vastus lateralis were taken before and after the test.
  
  
  RESULTS
  Beta-alanine increased leg muscle carnosine (32 ± 13 %, d = 3.1). Buffering capacity and incremental cycling were unaffected, but during 90-s severe cycling, beta-alanine increased aerobic energy contribution (1.4 ± 1.3 %, d = 0.5), concurrent with reduced O2 deficit (-5.0 ± 5.0 %, d = 0.6) and muscle lactate accumulation (-23 ± 30 %, d = 0.9), while having no effect on pH. Beta-alanine also enhanced motivation and perceived state during the HIT block. There were no between-group differences in adaptations to the training block, namely increased buffering capacity (+7.9 ± 11.9 %, p = 0.04, d = 0.6, n = 14) and glycogen storage (+30 ± 47 %, p = 0.04, d = 0.5, n = 16).
  
  
  CONCLUSIONS
  Beta-alanine did not affect buffering considerably, but has beneficial effects on severe exercise metabolism as well as psychological parameters during intense training phases.
authors.affiliation: Institute for Anatomy, University of Bern, Baltzerstrasse 2, 3012, Bern, Switzerland, micah.gross@baspo.admin.ch.
authors.forename: Micah
authors.initials: M
authors.lastname: Gross
authors.forename: Chris
authors.initials: C
authors.lastname: Boesch
authors.forename: Christine S
authors.initials: CS
authors.lastname: Bolliger
authors.forename: Barbara
authors.initials: B
authors.lastname: Norman
authors.forename: Thomas
authors.initials: T
authors.lastname: Gustafsson
authors.forename: Hans
authors.initials: H
authors.lastname: Hoppeler
authors.forename: Michael
authors.initials: M
authors.lastname: Vogt
mesh_terms: D000328:Adult; D002336:Carnosine / Q000378:metabolism; D019587:Dietary Supplements; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism; D010101:Oxygen Consumption; D055070:Resistance Training; D015091:beta-Alanine / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D015091:beta-Alanine; D002336:Carnosine