I went to work on a 60 hour a week construction project as a
laborer,   we worked ten hours a day.   I  was 22 when I
started. I grew from 145 lbs to 165 lbs in two years.   All
muscle.   I  suggest I could have imitated two babies
actions all day after that first two years and not become
tired.   Now I am 74  and more sedentary but I can still
work an ordinary day, but am in poor shape for really hard
work.  I have been involved in raising three generations of
babies;  They rest more than is the popular conception.

 I think it is lack of exercise and too many carbohydrates
in the diet that tires people.


>Adult "growth" is primarily *replacement* growth - a
> >breakdown and replacement of tissue - much less
> >efficient and requiring an entirely different nutrient
> >mix. Plus, adults are generally :) place much more
> >demand on their muscles and require more protein to
> >replace a greater muscle mass.
>
> If i look at my son ( 4 year old still breastfed ) and was
trying to use my
> muscle as much as he do all day long i will be exhausted.
I think he put way
> more demand on his muscles than i do .

> jean-claude