The main driver for muscle hypertrophy is known as the principle of progressive overload. This principle essentially states that in order to achieve the adaptations we desire, whether it be muscle gain or improvements in strength and performance, we must place enough stress on the body first (via training of course). Exposing ourselves to more and more stress/training stimuli forces our bodies to adapt in the ways necessary (through added muscle mass, power, strength, etc.) that makes performing easier for us over time. There are plenty of methods we can use in our training to progressively overload, some being: training frequency, training volume (sets, reps, weight), range of motion, rest periods, tempo, and forced reps or training to failure.
With so many different modalities to choose from, it can be a bit confusing for the beginner and intermediate athlete. Do we use all of these methods? Are some better than others? More frequently, though, the topic of whether training to failure is even necessary has been questioned. This is, not surprisingly, a controversial subject in the literature and one that still has had few studies investigating it. In the paper to be discussed, we not only gain insight into failure training, but we see these comparisons made in recreationally active women as well which is novel in itself.
Martorelli and colleagues wanted to explore training to concentric failure, and they wanted to do so with females. Both pretty novel aspects of this study! Now concentric failure is defined as the inability to complete a repetition in a full range of motion at a specific overload. This is commonly thought of as a good way to increase motor unit recruitment and mechanical stress, or in other words, another way we can induce muscular growth. However, it needs to be stated that training to failure has a lot of negatives to it – some including decreased recovery, increased fatigue, and drops in total work output. None of these being very conducive to muscle growth.
Prior to the 10-week training period, 89 recreationally active females were randomly split into three training groups: 1. repetition max to failure (RF), 2. repetitions not leading to failure with equalized volume (RNFV), and 3. repetitions not to failure (RNF). The training volume for repetitions not to failure with equalized volume (RNFV) was matched with the repetitions to maximum failure group (RF). Once split into their respective interventions, the subjects were told to maintain their normal nutritional habits throughout the 10-week period.
The maximum failure group (RF) performed three sets of repetitions to failure, working with 70% of their 1 rep max. The volume-equated group not training to failure (RNFV) performed four sets of 7 repetitions at 70% of 1RM. The researchers were able to equalize the volume between the RF and RNFV groups based on a pilot study they conducted with a smaller portion of this population (a subsample).
Finally, the non-failure training group performed three sets of 7 repetitions at 70% of 1RM, matching the sets of the RF group, just with submaximal sets (having lower training volume, comparatively). The exercise being done was a dumbbell bilateral bicep curl, and sessions were completed 2 days per week with rest intervals of 2 minutes. All groups were working with their corresponding loads calculated at 70% of 1RM, and these loads were increased by trainers over the 10-week period based on the 1 RM testing.
As stated above, all groups trained with the same 70% of 1RM loads for the duration of the study and following the 10-week period no differences were observed regarding these training loads between the groups. Training volume, however, did differ in that volume was significantly higher in the RF and RNFV groups than it was in the RNF group.
1RM strength was found to have significant increases among the RF, RNFV, and RNF groups similarly after the 10-week training period. The same can be said for muscular endurance as well, as all groups experienced a significant increase by the end of the training period.
After 5 and 10 weeks of training, the RF and RNFV groups both experienced significant increases in muscle thickness (i.e. muscle mass). The key finding here is that this large change was not seen within the RNF group. These differences could most definitely be due to the stark differences in training volume that the subjects were prescribed, as the RF and RNFV groups were equaled in their training volume while the RNF group had significantly lower training volume as discussed prior. This brings us full circle to the principle of progressive overload and is a prime example of how these added stressors will impact muscular adaptations, that being muscle gain in this case.
Application moving forward
The central purpose of this study was to decipher whether or not training to concentric failure is any more beneficial than submaximal training on its own. Much can be said regarding strength training, as strength is a skill that needs to be trained specifically, especially if you plan to compete in a strength-based sport, but overall training to failure is not a necessary means for strength gains, and can even do some harm by impairing the recovery process.
Granted that volume is taken into account and the trainee is pushing themselves adequately enough in the gym, training to failure is not determined to be a necessary stimulus for achieving muscle hypertrophy, nor is it any better than submaximal work. Both groups with higher training volume (RF and RNFV) produced higher measures of muscle mass development than the lower volume, RNF group, making a clear point that the subjects’ training volume of total work is more important than simply fatiguing the muscle targeted group in each session. Though, there is definitely an argument to be made where failure training can serve to demonstrate to the athlete how hard (or not hard in most cases) they are really pushing themselves in the gym. I find with my training clients, and even myself, that throwing in AMRAP sets will show me if the working sets are where they should be (aiming for that 7-9 RPE range).
All in all, using a greater total training volume proves to be more necessary in order to achieve muscle hypertrophy for female trainees. Progressively overloading over the training period while taking ample time to rest will be key in allowing those adaptations to take place and thus make progress over time.
Martorelli, S., Cadore, E.L., Izquierdo, M., et al. Strength training with repetitions to failure does not provide additional strength and muscle hypertrophy gains in young women. Eur J Transl Myol. 27 (2): 113-120.
Written By Gillian SanFillippo