I’ve wondered about this too, brick. Here’s what a quick scout of the net brought up.
If anybody out there has Paul Kelso’s book on shrugs, that has a chapter on the rib-cage that may shed light on this. I don’t have it, so I can’t say.
On T-mag (hooray) Charles Poliquin writes in Issue 38: “I’m not really keen on the crossbench pullover, as I’ve actually seen a few cases of herniated abs that were directly attributed to it. I’d rather have you do decline pullovers using an EZ bar, as they allow your shoulders to pivot more naturally.”
Also on T-mag, Don Alessi writes: “Contrary to bodybuilding lore, this exercise doesn’t expand the rib cage. Instead, this exercise is a lost favorite for back development.”
New York City Dawg, from issue 64, reviews Flex magazine and says: “There’s mention in one training article of the dumbbell pullover. Does it increase the size of the rib cage? Only if you haven’t completed your bone growth. Nevertheless, the pullover is an often-overlooked exercise. It’s great for developing the upper lats, lower pecs, and triceps, in addition to “lung power.””
I looked over some of the things on naturalstrength too. I wouldn’t call their claims scientific, and most of their training advice form the early years is pretty poor by modern standards, so I’d discount that as evidence myself, but I don’t think they were lying, just not understanding what exercise caused what. As for their “deep breathing” exercises, I find that hard to believe. If you’re exercising hard and heavy, you’ll have to breathe deeply anyway. It certainly taxes the lungs, and improves breathing power, vo2max and so on. But ribcage size? Doubtful. What they were right about is that improving lung conditioning benefits performance, strength, and the capacity for hard work with weights.
The idea of the pullover was popularised in the 20-rep “breathing squat” classic, where a superset of light pullovers holding the breath was performed too. The increase in the size of the rib-cage came from a very hard set of squats, not the pullovers. Holding the breath while trying to recover from such a hard exercise is probably not wise.
Does anybody know about those breathing resistance things popularised in the last few years? You put the thing in your mouth and breathe for say 10 minutes, and apparently it improves lung function. I’ve only seen them advertised, and i’m sceptical…