21 December 2018 Should You Train To Failure?
Training to failure is a controversial topic. Some argue that the last couple of reps are what really counts when it comes to strength and size gains, while others claim that stopping near failure is fine, and pushing to true failure does nothing but cause unnecessary fatigue and increase injury risk.
When training for strength, the evidence is clear that training to failure does not produce significantly better gains. Similar gains are made by training to failure or stopping just shy of it. Both are effectual methods, however, to improve efficiency and reduce injury risk, the recommendation to primarily stop short of failure and use training to failure sparingly is justified. (1)
Similarly, regarding hypertrophy, although less definitively due to less available evidence, it appears that training to failure is not superior to leaving a little left in the tank. (2-4).
Unpacking the research helps to understand why training to failure does not lead to greater gains, despite greater effort.
Training to failure, reduces how many reps you can perform on subsequent sets more than stopping short of it. If you’ve spent much time training, you have probably noticed that taking a set to absolute failure results in poorer performance on subsequent sets. (3)
Training to failure also elongates recovery time beyond the individual session. A study in 2017 by Navaro et al. (5) compared recovery for three resistance training protocols: The first protocol was 3 sets of 5 reps at a 10RM intensity (LVNF), the second protocol was 3 sets of 10 reps at a 10RM intensity (i.e. to failure) (HVF), the third protocol was 6 sets of 5 reps at a 10RM intensity (HVNF). Biomechanical markers of fatigue as well mechanical measures of neuromuscular performance were measured from -12 to +72 hours post exercise. Measures of performance were supressed for 24-48 hours in the HVF compared to both non-failure protocols and measures of muscle damage took twice as long to recover in the failure compared to non-failure protocols. The results of this study demonstrate that even when total volume and load is matched, training to failure has a considerable impact on the time course for recovery.
A 2018 study by Pareia-Blanco et al. (6) also investigated the time course of recovery between training to failure and stopping shy of it. This study compared recovery across different repetition ranges. Consistent with the previous study, they found training to failure elongated recovery time versus non-failure training, with higher rep sessions to failure being particularly fatiguing. Creatine kinase, a measure of muscle damage, was still significantly elevated at 48 hours in all failure training protocols, but not in non-failure protocols.
These findings provide evidence that it’s wise to avoid failure training, at least in some sessions, to meet weekly volume and frequency recommendations. A consequence of always training to failure is that the elongated recovery time could decrease volume or intensity throughout the rest of the week. Leaving some reps in the tank will probably leave you more recovered allowing better performance in subsequent sessions. For example, if you train squats to failure on Monday and intend to train them again on Wednesday, you likely have not fully recovered, and therefore will sacrifice volume or intensity. We know, intensity is a key variable for strength gains (7) and volume is a primary driver of hypertrophy (8).
To see application of these principles, we can refer to a 2017 study of 89 young women by Martorelli et al. (3) comparing performance outcomes for three experimental groups, all using a load of 70% 1RM with bicep curls, training twice per week. One group trained to failure for 3 sets (RF), a second group trained short of failure but volume equated, so 4 sets with fewer repetitions but same total (RNFV), and the final group trained short of failure for 3 sets (RNF). Strength increases were similar between groups. Although the RNF group completed less volume than the other groups, no significant difference was found in strength adaptations. This supports the idea that intensity is a key driver for strength and if volume is not drastically different, strength adaptations should be similar. In this study, the RNF group experienced less hypertrophy than the RF and RNFV groups. As volume is a key driver of hypertrophy, it’s not surprising that hypertrophy increased and was not significantly different between the groups with matched volume but did not significantly increase in the RNF group which completed less volume.
Increases in power output have also been shown to be superior when stopping shy of failure compared to pushing to failure. (3,9) The inferior result of training to failure is likely due to reduced velocity of the final repetitions.
What can we take away from these studies?
Within the context of one set, training to failure guarantees maximal stimulus, however it suppresses performance immediately and for days after when compared to leaving a little in the tank. As the goal of training is progress, leaving some in the tank will optimise gains over time, and is often the preferred option.
Failure still has a place in training. For example, on the last set of an exercise when there is adequate rest before the next session, or when testing repetition maximum. However, when training to failure is utilised it should be strategically planned for, so there is adequate rest between sessions and it doesn’t occur immediately before days you are chasing personal best performances.
Finally, it is unclear how far from failure you can train and still reap the same adaptations. You probably have to train somewhat close to failure. A good rule of thumb is to stop when you think you couldn’t perform another rep, or 1-2 reps shy of this.
- Davies, T, Orr R, Halaki M, Hackett D. Effect of Training Leading to Repetition Failure on Muscular Strength: A Systematic Review and Meta-Analysis. Sports Med. 2016 Apr;46(4):487-502. doi: 10.1007/s40279-015-0451-3.
- Martorelli S, Cadore EL, Izquierdo M, Celes R, Martorelli A, Cleto VA, et al. Strength training with repetitions to failure does not provide additional strength and muscle hypertrophy gains in young women. Eur J Transl Myol. 2017 Jun 27;27(2):6339. doi: 10.4081/ejtm.2017.6339.
- Nóbrega SR, Ugrinowitsch C, Pintanel L, Barcelos C, Libardi CA. Effect of Resistance Training to Muscle Failure vs. Volitional Interruption at High- and Low-Intensities on Muscle Mass and Strength. J Strength Cond Res. 2018 Jan;32(1):162–9. doi: 10.1519/JSC.0000000000001787.
- Sampson JA, Groeller H. Is repetition failure critical for the development of muscle hypertrophy and strength? Scand J Med Sci Sports. 2015;26(4):375–83. doi: 10.1111/sms.12445
- Morán-Navarro R, Pérez CE, Mora-Rodríguez R, Cruz-Sánchez EDL, González-Badillo JJ, Sánchez-Medina L, et al. Time course of recovery following resistance training leading or not to failure. Eur J Appl Physiol. 2017;117(12):2387–99. doi: 10.1007/s00421-017-3725-7.
- Pareja-Blanco F, Rodríguez-Rosell D, Aagaard P, Sánchez-Medina L, Ribas-Serna J, Mora-Custodio R, et al. Time Course of Recovery From Resistance Exercise With Different Set Configurations. J Strength Cond Res. 2018 Jul. doi: 10.1519/JSC.0000000000002756.
- Schoenfeld BJ, Grgic J, Ogborn D, Krieger JW. Strength and Hypertrophy Adaptations Between Low- vs. High-Load Resistance Training. J Strength Cond Res. 2017 Dec;31(12):3508-3523. doi: 10.1519/JSC.0000000000002200
- Schoenfeld BJ, Grgic J, Krieger J. How many times per week should a muscle be trained to maximize muscle hypertrophy? A systematic review and meta-analysis of studies examining the effects of resistance training frequency. J Sports Sci. 2018 Dec 17:1-10. doi: 10.1080/02640414.2018.
- Carroll KM, Bernards JR, Bazyler CD, Taber CB, Stuart CA, Deweese BH, et al. Divergent Performance Outcomes Following Resistance Training Using Repetition Maximums or Relative Intensity. Int J Sports Physiol Perform. 2018 May 29:1-28. doi: 10.1123/ijspp.2018-0045.