Acute L-glutamine ingestion does not improve maximal effort exercise

J Sports Med Phys Fitness. 1998 Sep;38(3):240-4.

Abstract

Background: L-glutamine (GLN) may have an ergogenic effect during exercise considering its base generating potential. We attempted to determine whether GLN ingestion influences acid-base balance and improves high intensity exercise performance.

Method: Ten trained males performed five exercise bouts on a cycle ergometer at 100% of VO2 peak. The first four bouts were 60 sec in duration, while the fifth bout was continued to fatigue. Each bout was separated by 60 sec of recovery. The exercise bouts were initiated 90 min after ingesting 0.03 g.kg body mass-1 of either GLN or placebo (PLC). Venous blood samples were collected pre-ingestion (PRE-IN), pre-exercise (PRE-EX), and following bouts four (B4) and five (B5) and analyzed for pH, bicarbonate concentration (HCO3), and lactate concentration (La-). Time to fatigue for B5 was used as a performance measure.

Results: pH, [HCO3], and [La-] were not significantly different (p > 0.05) between conditions for PRE-IN, PRE-EX, B4, and B5. Time to fatigue was not significantly different between conditions and averaged 263.4 +/- 24.5 sec and 263.2 +/- 19.4 sec for the GLN and PLC trials, respectively.

Conclusions: These data indicate that acute ingestion of L-glutamine does not enhance either buffering potential or high intensity exercise performance in trained males.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acid-Base Equilibrium / drug effects
  • Acid-Base Equilibrium / physiology
  • Adult
  • Bicarbonates / blood
  • Cross-Over Studies
  • Double-Blind Method
  • Exercise Test
  • Fatigue / physiopathology
  • Glutamine / administration & dosage
  • Glutamine / pharmacology*
  • Humans
  • Hydrogen-Ion Concentration
  • Lactates / blood
  • Male
  • Physical Endurance / drug effects*
  • Physical Endurance / physiology
  • Physical Exertion / physiology*
  • Placebos
  • Psychomotor Performance / drug effects
  • Psychomotor Performance / physiology
  • Rest / physiology
  • Time Factors

Substances

  • Bicarbonates
  • Lactates
  • Placebos
  • Glutamine