title: Hydration status does not have a significant effect on soleus motoneuron pool excitability.
abstract: The purpose of this study was to examine the effect of hydration status on the soleus Hoffmann reflex (H-reflex): muscle response ratio in nine healthy subjects. Soleus H-reflex, urine specific gravity (USG), and body weight (BW) were collected prior to and following a 12-hr fluid restriction protocol and compared to euhydrated measures. Individual repeated measure ANOVAs compared H-reflex, USG, and BW across conditions. A main effect for hydration status was observed between the hypohydration and euhydration condition (p < .01). H-reflex and BW demonstrated no change from baseline across conditions. Although hypohydration creates deficits in muscle function, it does not appear to be the result of decreased central activation.
authors.affiliation: Ohio University Sports Medicine Research Laboratory, Division of Athletic Training, School of Recreation and Sport Sciences, Ohio University, Athens, Ohio 45701, USA. krausea@ohio.edu
authors.forename: Bentley A
authors.initials: BA
authors.lastname: Krause
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Hoch
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Doeringer
authors.forename: Clint R
authors.initials: CR
authors.lastname: Sheets
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001835:Body Weight / Q000502:physiology; D003681:Dehydration / Q000503:physiopathology*; D004558:Electric Stimulation / Q000379:methods; D004576:Electromyography / Q000379:methods; D005260:Female; D006112:Gravitation; D006181:H-Reflex / Q000502:physiology*; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D011999:Recruitment, Neurophysiological / Q000502:physiology; D014868:Water Deprivation / Q000502:physiology*; D055815:Young Adult