Acute L-glutamine ingestion does not improve maximal effort exercise.
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.


METHODS
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.
Haub
M D
MD
Exercise Physiology Laboratory, University of Kansas, Lawrence 66045, USA.
Potteiger
J A
JA
Nau
K L
KL
Webster
M J
MJ
Zebas
C J
CJ
D000136:Acid-Base Equilibrium / Q000187:drug effects / Q000502:physiology; D000328:Adult; D001639:Bicarbonates / Q000097:blood; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005080:Exercise Test; D005221:Fatigue / Q000503:physiopathology; D005973:Glutamine / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000097:blood; D008297:Male; D010807:Physical Endurance / Q000187:drug effects* / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D010919:Placebos; D011597:Psychomotor Performance / Q000187:drug effects / Q000502:physiology; D012146:Rest / Q000502:physiology; D013997:Time Factors
D001639:Bicarbonates; D007773:Lactates; D010919:Placebos; D005973:Glutamine