your a fucking moron
the requirement of balance also helps build muscle, and if you do walking lunges you should have no stress at all on the knees because
your body should be travelling straight down towards the floor and not forward to put stress on the knees
plus if you actually have balance, you do not use much energy at all for balance, it is all used for contraction and stretch of the muscle plus
very taxing for the cardiovascular system
try again slappy
now you are one of these people that make my life miserable...i.e. blissfully ignorant to anything and you dont even realise how average you are.
i wont bother answering your email point by point to give you an example of what i mean but i will comment on your stupid sentence about strain on the knees...obviously you dont have a clue.
the simply fact that the legs are not in the centre of your body means that each leg encounters a vertical and a horizontal stress when you stand on it...dumb ass.
the horizontal stress component is relatively minor and our knees and ligaments can cope with it generally....but you add weight and then difficult movements like lunges and you have danger zone.
the centre of mass in a lunge is NEVER directly over the leg...EVER... EVER .. EVER.
its also never directly acting straight down the spine. (you may not understand this but this is due to the fact that the reactional force (i.e. through the leg from the ground) is from one side.
I'd suggest that lunges are not only your chiropractors nightmare (or best friend perhaps?..lol), but also the fastest way to a knee reconstruction other than football.