Is it necessary to carry out the set to failure? What is the evidence of training to failure efficiency?
Even 25 years ago, such a question did not come to those training in the basements and garage gyms. Of course, it is necessary, because it is from this that muscles grow, but modern scientific experiments have shown that repetitions close to failure also stimulate muscle growth, as well as failed ones. This is just a conclusion, but the interpretation of research may be different.
The science behind training to failure
To begin with, let’s define the concept of failure because there are various interpretations. We accept for failure the impossibility of technically correctly performing the concentric (reduction) phase of motion with a given amplitude.
Now consider the results of several experiments. In one, two groups performed the same amount of strength work equal to 24 repetitions, but in the first case, 4 sets of 6 reps to failure, and in the second case, 8 sets of 3 reps without failure.
In the other, both groups performed 10 repetitions in the set, but in the first group to failure, and in the second after 5 repetitions, a 30-second rest followed by another 5 repetitions.
As you might imagine, the groups performing the set(s) to failure have shown more significant results in the increase in strength and muscle mass.
It would seem that the conclusion is obvious – failure is necessary. But everyone understands that the hypertrophic contribution of each repetition in the set is different as well as the amount of useful work.
By the amount of useful work, we propose to understand the combination of factors that stimulate muscle growth, and this is mechanical stress (weight of the load) and metabolic stress (acidification of the trained muscle).
With an equal volume of work performed in these experiments, the volume of USEFUL work significantly differs. But if in the experiment, in non-failure groups, the volume was increased by 2–3 times in relation to the failed ones, then the result would probably be different.
Evidence against using failure sets
A striking example of impressive muscles without work to failure are athletes of speed – power sports (discus, spear throwing, etc.). How do they succeed? With a seemingly low hypertrophic value (and they don’t need it) of their training, in total, they perform a huge amount of useful work, which leads to such impressive results.
Is failure in bodybuilding necessary?
In bodybuilding, we perform an exercise in order to achieve severe fatigue in a specific muscle group, which we strive to develop by performing this exercise. Only repetitions close to failure are called “highly hypertrophic” (quoted by James Krieger).
Fatigue and true failure are far from the same thing. For example, squats with a bar, which is performed for the development of quadriceps, can be completed not because of a failure of the target muscle group, but because of general fatigue, a pulse under 200 or (and) due to a lack of will to continue the set.
Moreover, if by failure we mean the impossibility of technically correctly performing the concentric (shortening) phase of movement with a given amplitude, then, for example, with the bench press, the last repetition, during which you are able, without wriggling under the barbell, to return it to the racks by yourself is not done to failure, it is pre-failure, but 90% consider it to be a failure.
When performing single-joint exercises, for example, bicep curls with a barbell until you start to cheat (use inertia), the repetitions will not fail.
It turns out that in the absence of help (but not the presence of an insurance partner) in the bench press, squats, (and help is already forced repetitions) or cheating on biceps, shoulders, etc. we do not work to failure, but in the way that scientists advise and there is essentially no subject for discussion.
If we are talking about low-intensity training with 30-60% of 1RM, then the scientists (and us) made an unambiguous conclusion – the increase in muscle mass during training with high (large lifted weight) and low intensity (low weights) give similar scales of muscle growth.
But in order for low-intensity workouts to be comparable with the effectiveness of heavy ones, you need to work until real failure!
So, training to failure in most cases is in our heads.
Additionally, see how to choose weights for workout correctly.
What is more, why not read the answer to what is better: fast or slow reps?