So, a resting pulse rate for 79 is perfectly normal. Conditioned athletes might have a much lower resting pulse rate. 100bmp and higher is considered tachycardia, although for some people, this could just be normal.
A. One space after a colon. There is a traditional American typing practice, favored by some, of leaving two spaces after colons and periods. This practice is discouraged by the University of Chicago Press, especially for formally published works and the manuscripts from which they are published.
In business letters in the United States, a colon is standard after the greeting, and a comma is standard after the complimentary close. I have never heard the explanation you offered for using two spaces.