Crying is good for the lungs????

The question came to me this week on whether crying was good for a baby's lungs. I am doing some research so that I give you evidenced-based information. But has anyone else heard this?

Here is a direct quote from askdrsears website: 
    Crying isn't "good for baby's lungs." One of the most ridiculous pieces of medical folklore is the dictum: "Let baby cry, it's good for his lungs." In the late 1970's, research showed that babies who were left to cry had heart rates that reached worrisome levels, and lowered oxygen levels in their blood. When these infants' cries were soothed, their cardiovascular system rapidly returned to normal, showing how quickly babies recognize the status of well being on a physiologic level. When a baby's cries are not soothed, he remains in physiologic as well as psychological distress. (end of quote)