Effects of acute exercise on the soleus H-reflex and self-reported anxiety after caffeine ingestion.
The effects of moderate intensity cycling exercise on the soleus H-reflex and state anxiety were examined among 16 individuals whose anxiety was experimentally manipulated by consumption of a large dose of caffeine. The soleus H-reflex and state anxiety were measured before and 1 h after consuming caffeine or placebo and then again 10 min after 30 min of either cycling at an intensity of 60% VO(2peak) or quiet rest. We found that (1) caffeine consumption did not influence the amplitude of the soleus H-reflex, but it did increase state anxiety; (2) acute exercise reduced the soleus H-reflex after consumption of either caffeine or placebo, but it reduced state anxiety only after consumption of caffeine; and (3) there was no evidence of a relationship between changes in the soleus H-reflex and state anxiety. Exercise-induced anxiolysis does not appear to underlie the postexercise reduction of the soleus H-reflex.
Motl
Robert W
RW
Department of Exercise Science, University of Georgia, Ramsey Student Center, 300 River Road, Athens, GA 30602-6554, USA.
Dishman
Rod K
RK
D000328:Adult; D001007:Anxiety / Q000139:chemically induced / Q000503:physiopathology* / Q000628:therapy; D002110:Caffeine / Q000009:adverse effects*; D000697:Central Nervous System Stimulants / Q000009:adverse effects; D015444:Exercise / Q000502:physiology* / Q000523:psychology; D005080:Exercise Test; D005081:Exercise Therapy; D006181:H-Reflex / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects / Q000502:physiology; D012647:Self-Assessment
D000697:Central Nervous System Stimulants; D002110:Caffeine