Hydration status does not have a significant effect on soleus motoneuron pool excitability.
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.
Krause
Bentley A
BA
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
Hoch
Matthew C
MC
Doeringer
Jeffrey R
JR
Sheets
Clint R
CR
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