One more question... does lifting weight make your rest rate drop?

I've got a rather low rest rate already, and it is either a glitch , or my numbers are getting seriously low... I saw 29 again this morning.
I have seen that number only once before: a few days after a vaccination for yellow fever (prior to leaving for South America).
I had a cardiogram made but everything seemed fine..

Should I be worried? My fit rest rate is 32-35 bpm. Somehow a number with a 2 in front makes me feel much more worried than 30 or 31