There are lots of examples of peopel lifting 6-7 days a weeks some of them even multiple session a day. For example OLY lifters, the bulgarian method is brutal training twice a day for 7 days a week maxing out almost 90% of the time. John Broz still trains his OLY lifters that wat and gets good results from it.
Though as I said before it can be done but not withoud propper periodisation.
There are Two Types of Pain in this World: The Temporary Pain of Discipline, or the Permanent Pain of Regret!