about training to failure

[cathal]

i hear a lot about not training to failure,that you should be able to do 2 reps more than when you stop. im fairly new to lifting and the when i lift i usually weigh it do the last rep takes an almighty lift.
is this bad,and if so why?

 

[cathal]

sorry just realised theres a whole thread on tjis exact matter,making this one pointless.