Training to failure, RPE 10, maxing out.
No matter what you call it, taking your sets to their breaking point and seeing how much you truly have in you is mentally and physically hard work.
It would seem that this type of training has incredible value right?
Work hard, push your limits on every set, experience wonderful gains. But it's actually not that straight forward.
Digging deep holes
Failure in training, is going until you physically can't do any more. Volitional or technical failure is when you go all the way until you literally can't lift back up and crash into the safeties or your technique breaks beyond an allowable threshold. There is also a continuum of exertion to consider, with failure being the end point. but before that final failure point, there is plenty of grey area for highly fatiguing training that comes within proximity of this failure point, where you might be grinding harder than is optimal.
For the purposes of this article, let's talk about training to failure as a range of exertion efforts, anything RPE 9 or beyond 35% fatigue on a consistent basis (multiple sets per week, most weeks of a training block)
Unfortunately (or fortunately, depending on how you view it), making this grinding, close-to-failure type training a consistent element of your program is actually not that effective, and in fact might even be holding you back.
This harder training leads to large accumulations of both neural and peripheral fatigue, delaying recovery and making it harder to come back and train with good intent and intensity next session. So there exists a trade off at play, going all out in a single session and spending more time within proximity to failure might be a good approach for that single training session IN ISOLATION, but it is when we consider each training session as a single brick on the path to improved strength and power that this extra work and effort no longer stacks up.
The above illustration highlights how this works over a theoretical training week. The athlete who goes harder in the first session has to take more time between sessions as they recover from the stress, while the athlete who trains further from technical failure (a lower RPE, less velocity loss) has shallower, shorter fatigue periods, meaning they can accumulate more training sessions in the week making greater accumulated progress.
Short term fatigue
Here is a clear example of how training to failure might be doing you wrong, especially in the short term.
Gonzalez-Badillo, 2016 (1) looked at the effects of a single training session on jump performance in the immediate days following the session.
Two groups did a workout of either 3x8 or 3x4 and the researchers then monitored their jump height pre and post the session to see how their lower body power responded to the two different training stressors.
This graph is just a snippet from the paper, but when we compare both groups to their baseline performance (100%) its really interesting what happens next.
Immediately after the training sessions, both groups dig a massive hole in their power. The 3x4 group loses about 20% of their jump height, while the 3x8 group loses in excess of 30% on their jump height. That could be as much as a 20cm drop for a 60cm jumper in the 3x8 training group.
Two days after the session the group that did the smaller training session (3x4) has now actually supercompensated and has a higher vertical jump than they did in the baseline test. Mission accomplished, the training was effective!
Meanwhile, the 3x8 group is STILL showing signs of fatigue, with their jumps still about 5% off their baseline performance. For our theoretical 60cm jumper, they are now only jumping 57cm, so even two days after the training session they are still in the hole, with 3cm wiped off their jump potential!
If your goal is to increase performance or simply not to have your athletes be worse in the days after they train, do less reps, dig smaller holes and prioritise recovery.
Long term adaptation
If harder training digs a deeper hole in the short term taking longer to recover from, how does that play our over the weeks and months of adaptation to come?
Izquierdo-Gabarren, 2010 (2) looked to answer this question with three groups of Kayakers following three different training plans for a block of upper body strength and power:
- 2x sets not to failure*
- 4x sets not to failure (20%)
- 4x sets to failure (40%)
(NB: I have removed the 2 set group from the graph to highlight the 4 set groups. The two set group ended up somewhere in the middle across the eight weeks.)
The group that trained to failure completed almost TWICE the amount of reps as the submaximal groups, yet they saw 80% LESS progress in their upper body power than the easier training group.
So how little work can we get away with? What is the minimal effective dose?
When you consider all three groups, it becomes clear that we still need to reach a certain threshold for training volume (4 work sets were better than 2) but the amount of exertion and the proximity to failure within each of these sets is not essential for making progress.
Leaving a few reps in the tank is the smarter way to go about it.
Another study (3) on training to failure showed similar results
This one is another use of the classic 20% vs 40% velocity loss, and again it's a pretty clear cut advantage for the 20% group.
Training to failure: A case study
It wouldn't be right for me to go talking about training to failure without showing what that looks like right?
So here is a case study of 1, breaking down some sets to failure from a velocity based training perspective.
Safety's up and ready, I used seats to keep a consistent ROM and a few prayers for kindness on the DOMS. In these two videos I took 90kg (1xBW) & 67.5kg (75% xBW) for a spin to technical failure. All in the name of science!
This was probably the first time I have done more than 10 reps of any movement in possibly 4 years, and I ended up at 6 on the 90kg and 20 on the 67.5kg!
On both sets I reached only reached 32-33% velocity loss, A little short of the typical 40% yardstick for failure.
*Maybe I'm not very neuromechanically efficient and therefore not as good at grinding it out?
Or possibly squatting above parallel changes the fatigue relationship compared with the full range of motion squats used in research?
NB: As an aside I also did two sets to failure on bench press and got 50%+ fatigue on both sets.
Possibly upper and lower body have differences in endurance profiles?
Back to the squat sets: On both sets, there seemed to be an inflection point after passing 20% fatigue where the velocity drops at an accelerated rate. Some kind of fatigue cliff brought on by my training history?
The two sets also had quite different final velocities, probably because the set of 20 was becoming more of an energy systems issue than strength. The 90kg set ended at 0.32m/s, in good alignment with an actual 1RM test from December last year of 0.36m/s.
I wonder if a set of 10-12 would be closer to 0.4 or 0.35?
I guess we will never know...
It may look like this was a tough and high value piece of training, but the science on training to failure is building more and more to say the exact opposite.
Doing less - and leaving reps in the tank - is actually a superior training method in both the short term recovery and long term adaptation.
Alternative approaches to your training
So now armed with the knowledge that training to failure is probably slowing down your progress, you are avoiding regular max out sets. Instead doing the bulk of your work sets in that higher quality zone of RPE8 with only 15-25% velocity loss.
But it doesn't feel like you are doing enough work right?
You still need to go hard in the gym, can't let the competition go catching up.
So whats the solution? How can we train hard but still avoid the trap of training to failure?
Do more sets.
This meta-analysis* (4) combined the results from 25 different studies exploring training to failure.
Overall, athletes who performed more sets saw greater gains in strength for both submaximal and maximal training plans, BUT - and its a big BUT - submaximal training was an ASTRONOMICALLY more effective strategy across all set numbers.
So whether you are a time efficient lifter squeezing in two quick working sets before work, or you bring a cut lunch to the gym for a six set squat super session, leaving a few reps in the tank for each set is going to lead to greater strength improvements.
Train with clusters
Another great approach to minimise fatigue accumulation in your training without compromising workout density is to use cluster sets (5).
Clusters are a reimagining of traditional strength training. It simply introduces more frequent short blocks of rest into the exercise, enabling you to maintain higher training velocities.
The best part about clusters is that when they are planned correctly they can actually be a more efficient way to train, allowing you to:
- Lift the same weight
- Perform the same number of reps
- With the same total rest
All while achieving a higher average velocity across the session!
Who says you can't have your cake and eat it too?
This table contains a few example cluster arrangement that all workout to approximately the same 5-6 minutes of total rest.