When Should You Train To Failure?
The good news: Taking a set to absolute failure creates a greater training stimulus than not doing so.
The bad news: It also creates a disproportionate amount of fatigue, which can negatively affect the rest of a workout or your other workouts that week.
This means that most sets should be taken to about 2-3 reps away from absolute technical failure. This way you still get most of the training stimulus but at a much lower cost in terms of fatigue.
Note: I used the term "technical failure" to stress that sets should never be taken past the point of form breakdown. Every single rep should always look exactly the same, aside from speed.
Failure: The Right Time and Place
There is definitely a time and place to take your sets to failure. They include:
- On "small" exercises and/or muscles: Even if you take all of your curls to failure, it won't really create a lot of damage or stress to your CNS, so most times you can hit arms and calves hard without worry.
- On ANY exercises where you're not strong enough to use much weight. Smaller or weaker people simply can't tax themselves as hard as bigger or stronger people, even if they're training as hard as they can. For example, if your max squat is less than 200 pounds, you should probably take most of your sets to failure.
- On the last work set of an exercise: At this point, you're not saving yourself for any further sets of the same exercise, so unless it's a really taxing movement (like deadlifts or squats) you can take that last set to failure.
- On the week prior to a deload: If you know that you'll have a planned light week coming up (or a vacation the next week) then train right to failure, at least on your last work sets.
- During occasional strength testing. If you never take sets to failure, you'll never really know how strong you are. Look for opportunities to break your PR's for sets of 10, 5, 3 or even singles when the time is right!
- When you're only going to do one set anyway: The old "one set to failure" approach has been pretty much discredited as an optimal training strategy, but hey, we all have times when time and energy is limited. In those situations, one hard set is light-years better than zero sets. So if you can only do one set, go balls-out.
Costs vs. Benefits
Always remember that lifting weights has benefits, but it also has costs, particularly in the form of fatigue. Remember that training is a process, not a one-time event. Every time you do a set, it pays to consider how it will affect the work that will follow.