If you were running a dosage of test at 500mg for 8 weeks, but used 1000mg for the first week only, then you would be "front loading" 1000mg test..."Front loading" is supposed to allow for the testosterone to build up in the system faster to give quicker gains...this makes little sense considering the half-lives of long acting esters....this is why most people run fast acting drugs in the beginning of cycles, rather than front loading to bring about quicker gains.
But, some people do like this method...find out what works best for you. If your supplies give you an extra ml or two when you have calculated the amount of steroids needed for you cycle, it doesnt hurt to add it in in the beginning.