Effects of acute exercise on the soleus H-reflex and self-reported anxiety after caffeine ingestion

Robert W. Motl, Rod K. Dishman

Research output: Contribution to journalArticle


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% V̇O2peak 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.

Original languageEnglish (US)
Pages (from-to)577-585
Number of pages9
JournalPhysiology and Behavior
Issue number4
StatePublished - Jan 2004



  • Anxiety
  • Caffeine
  • Exercise
  • Hoffmann reflex

ASJC Scopus subject areas

  • Experimental and Cognitive Psychology
  • Behavioral Neuroscience

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