i haven't done too much formal reading on this but i was wondering if anyone knew of any scientific reasons for the typical one week training cycle. i know in hs and college races tend to be on a weekly basis so i guess it helps with routine. for example, is it really ideal to do a long run once every 7 days. why not 6, or 8 or 10? i do think there is something to be said for a weekly routine as that is what we are used to from the rest of our lives and enables us to integrate running into our normal lives. but what does the science say? if this has been discussed before please point me in that direction