> I would love to see a source for this that thinking about something uses more oxygen. 10 years ago I could swam 50 meters. At that time I was doing tai-chi,

> I would love to see a source for this that thinking about something uses more oxygen. 10 years ago I could swam 50 meters. At that time I was doing tai-chi, meditation etc... 'Proper study' is here http://www.ncbi.nlm.nih.gov/pubmed/11352604 http://www.ncbi.nlm.nih.gov/pubmed/11352604