'Training to failure' has been a topic of discussion for a while now.. but what does it even mean?
Technically, training to failure can be defined as the inability to complete the concentric portion of a given lift without substantially deteriorating your technique.
When we refer to 'failure' we actually mean 'task failure' and not 'muscular failure' because in reality it's not our muscles that fail, but rather our ability complete the given task with a given weight.
Is it important to train to failure?
While it's certainly not optimal to 'always' train to failure, the opposite isn't true either:
For any given set, there's an amount of adaptation stimulus and fatigue that comes along with it. Training to failure definitely increases the amount of CNS fatigue we may experience, which could be sub-optimal for future workouts - HOWEVER - if we never experience true failure, we may never be able to reach the required amount of effort threshold that we need to stimulate growth, because we wouldn't be as precise at dictating it.
Of course this comes more with experience, and the more advanced you'll get the more precise you'll be at performing the exercise correctly under high intensities.
Personally, as a coach, I believe it's important to understand what failure actually is and what it feels like, so that we're more likely to be precise in how we rate our perceived effort exertion within a given set. Because we'll still need to train close to it, for the stimuli to be meaningful. This means that here and there, it's actually a good idea to be prescribed a set of X reps to RIR 0 for a set of an exercise. Feel it. Understand it. Learn it.
What do you think about training to failure?