Elphaba
Please, please actually read my, DrRanj's, curry's et al posts about how and when we carry our children. PLEASE. I say, once more with feeling, IT IS NOT CONTINUOUS, it is occasional, and it is almost always to promote physical activity for the whole family, or to manage a child where there is no alternative.
Some posters here claim to carry their older children very frequently, and base the claim that they are not doing damage to their pelvic floors on the assertion that they are thus fitter than people who carry them only infrequently.
How occasional is 'occasional'? Is it frequent enough to be sure you could balance on a narrow plank mentioned by a pp, or frequent enough that your child knows not to wiggle or bounce as you navigate planks or other hazards, or swing their head around just for the heck of it, throwing you off balance? Or is it once every few months or so, in which case, how do you know your back and pelvic floor (my main concern is with the pelvic floor) won't be strained by a child who has gone through a growth spurt?
Greatbigwho - some people are talking about extended hikes here (not everyone of course).
Jeffy
You generally realise too late that you have pelvic floor problems. You would have to be really foolhardy to attempt to carry a heavier child on your back if you already knew you had a problem. The point about the pelvic floor is that bad habits catch up with you as you hit early middle age, and onwards. You can then regret at leisure the poor decisions you made when you were young and thought you were invincible, the kegels you neglected, etc.
53rdWay
all those army folk and long-distance hikers carrying around rucksacks for miles aren’t building up muscle strength at all!
Their muscle strength is developed through all round exercise that does not focus entirely on the muscles necessary to schlep a heavy older child on your back (or front). Many are serious weight lifters, developing their legs, arms, shoulders and necks alongside core and back strength. If all you do by way of building muscle strength is carrying a child on your back (occasionally, according to some) then you are not only not developing muscle strength, you are risking injury. So I repeat - Strength training for back issues is not the same thing as carrying a child on your back for a few miles on a regular basis. And I will add, it's not the same at all as carrying a child on your back occasionally, which is apparently what we are really talking about here.
I included the link to the Marine Commando training in response to Jeffy who implied that if superfit (and mainly male) candidates for the Royal Marines could carry 40 lbs then women with no specific fitness level or general fitness or stamina training, and obviously having gone through pregnancy and childbirth whether vaginal or CS, could too.
The final Royal Marines commando test, done at the end of their training- is a 30 mile march with backpacks containing around 40lbs of weight. They know a thing or 2 about fitness and do not get overly concerned by the risk of back pain?
What I am trying to suggest is that there is no comparison.