Depends on what you mean. If you mean can you adjust to going to failure all the time (which seems to be implied by what you said) then no, you can’t adjust to it. Your nervous system won’t let you.
If you want to adjust to a higher level of intensity, the way to go is to lift frequently, heavy but NEVER to failure. For example, do triples with your 5-rep max. Olympic lifters and many powerlifters train this way. This method is designed to train your nervous system as much as grow your muscles.
If you don’t have a caloric surplus, all it can do is train your nervous system - useful for lifters who want to stay in a weight class.
Of course, intensity can mean a variety of things. For the HIT Jedis, it is all about going to failure. The truest definition of intensity is probably the % of your 1RM - but then again, as Dan John pointed out in his latest article, a 1RM can mean a number of different things. O-lifters would normally take this to mean the % of the max you were capable of on the day.
Another method to train the nervous system, used by many powerlifters, is speed work. This uses weights only around 50% 1RM, moved as fast as possible, in low rep sets (doubles or triples). The reasoning behind this is that weights around this level generate the maximum force (remember F=mA from high school physics).
The high acceleration more than compensates for the lower mass. by generating the maximum force, this maximises muscle fiber recruitment.