Keeping your pages lightweight is the best way to avoid any reloading
appearance.
Each time you go to a new page, the code for that page must be fetched from
the browser. If the page is 'verbose' that fetch can produce a noticeable
delay between the blank browser viewport and the rendering of the page's
code. However, graphics on that new page should be pulled from the local
cache when needed rather than fetching them again from the server.
So - the bottom line is that each new page must "reload". Ordinarily this
is an insignificant delay, even on sites that use a fair amount of graphics.
For example, visit this site of mine -
http://www.raphaelarchitects.com.
This is a reasonably graphic-heavy site. Yet I don't find the reloading as
you transit from page to page to be unpleasant, or even undesireable - do
you?