The more you think the worse you'll perform

Today's workout (elliptical): 25 minutes

Perhaps there is something to the idea of "clear mind, sound body." I followed a link put up by blogger/podcaster cyktrussel who publishes http://www.runrunlive.com/ that states "intense thinking could [also] affect a competitive athlete’s performance." The term used in the article is "ego depletion" and the article further states that "the harder you think, work or stress right before a practice or race, the worse you will perform." 

Perhaps the next time I have a bad run or workout, I'll blame it on my tendency to think too deeply.