Should You Train To Failure?

Now our minds automatically think, the harder we push the more gains we will make with our strength and muscle size. However, would training smarter and not just harder lead to more strength and muscle growth?

In either case that’s what we will be taking a deep dive into today with a new Meta Analysis just published on training to failure along with 2 Systematic Reviews with Meta Analysis and a stand alone study.

IN THIS ISSUE:

• 🔥 What is “training to failure” and how to measure it.

• 🔬 New Meta Analysis on training to failure

• 🥼 More Scientific Literature

• 💪 Key points & practical applications

LIGHT WEIGHT BABY
Training to Failure & How to Measure it.

There are two ways to define failure in the gym:

1. Technical Failure: when you stop that set when you feel your technique has begun to fail.

2. Momentary Muscular Failure: when you physically can't complete another rep sometimes referred to as (concentric failure).

For this issue I will be focusing on Momentary Muscular Failure, so when training to failure is referenced, that’s what I’m talking about. Not just a poorly executed squat, you know who you are…

The main idea behind training to failure is that as we reach muscular failure, we reach maximum motor unit recruitment, meaning more muscle activation and more potential muscle growth.

However a comparative study by (Sundstrup et al., 2012) found that EMG readings (which measure muscle activity) increased throughout a set to failure, but hit plateau around 3-5 reps from failure.

How we can best measure failure is by using a method called Reps in Reserve (RIR). Just as the name implies, we simply judge how many reps we have left in the “tank” or how many more we could have completed in a given set before failure.

The main argument some give against the RIR method is that we will miss judge our RIR, due to it just being taxing and simply call it a day.

A Meta Analysis was carried out by (Halperin et al., 2021) exploring just how accurate we can predict our own RIR. The researchers analysed 13 publications including 12 studies with a total of 414 participants. The results showed that participants in the studies underpredicted their RIR by 1 repetition. Further, participants were able to predict their RIR more accurately the closer to failure they trained and if the set repetition volume was less less than 12 per set.

Again the RIR methods validity was tested by (Lovegrove et al., 2021) a study, published in the Journal of Strength & Conditioning. The researchers took 15 novice lifters (under 1 year experience) to test the deadlift and bench press using the RIR method. They found the subjects were able to accurately use RIR to determine load for a given rep range, suggesting that even in novice lifters, the RIR method can be a reliable tool.

Before we get started, just a refresher on what evidence I’m referencing. 

THE EVIDENCE
The New Meta Analysis

Carried out by (Robinson et al., 2024) and published in the Journal of Sports Medicine, they collected data from 55 different studies. The aim was to perform a detailed statistical analysis comparing how different reps in reserve levels affected strength and muscle growth.

The results showed that strength gains where similar across various RIR’s meaning there seemed to be no dose response relationship between how close study participants trained to failure and their strength outcomes.

Where as hypertrophy outcomes improved with a dose response relationship as sets where taken closer to failure or to failure.

Below are two figures from the study showing the results from the Meta Analysis in relation to improvements based on RIR. Figure 1 is for hypertrophy. Figure 2 is for strength.

MORE EVIDENCE
We Want More Stats…

A Systematic Review and Meta Analysis by (Vieira et al., 2021) included a total of 384 test subject from 13 studies (all studies must have lasted longer than 6 weeks). The aim was to compare training to failure vs not failure on strength and hypertrophy outcomes. Of the 13 studies, 8 used equated total training volume. The overall results show no difference between training to failure vs not failure on strength, however strength did favour the training not to failure group when volume was not equated when the researchers done a sub-analysis. Hypertrophy results overall showed greater gains when training was taken to failure, the sub-analysis showed only marginal benefits to training to failure when volume was equated.

Another Systematic Review and Meta Analysis by (Grgic et al., 2021) compared training to failure vs not failure on strength and hypertrophy outcomes. A total of 15 studies were included, the results of the meta analysis showed no differences between outcomes on either program. The sub-analysis showed “significant” favour to the training not to failure group when volume was not equated for strength outcomes. Researches state: “Training to muscle failure does not seem to be required for improvements in strength and muscle size. However, training in this manner does not seem to have detrimental effects on these adaptations, either".

An interesting research paper published in the Journal of Strength & Conditioning by (Lacerda et al., 2020b) had 10 male subjects perform training to failure with one leg and not failure with the other leg with the leg extension machine using equal volume for 14 weeks. At the end of the 14 weeks, strength adaptations were the same between each leg and the non muscular failure leg group actually saw slightly better increase in muscle size.

JUST FOR YOU
Key Takeaways & Practical Applications

• Training to failure seems to be not necessary to maximize strength.

• Training to failure, from the majority of research, shows a dose response relationship towards better muscle growth the closer to failure you go. However with diminishing returns.

• The RIR scale is a somewhat reliable way to measure how many reps we have left in the tank, however we do tend to undershoot our estimates by 1 rep on average and accuracy improves as we approach failure.

If you want to increase muscle mass, for most, training closer to failure may be the best option, as it seems to improve the accuracy of our RIR reporting. Taking a set to failure removes the inaccuracy of self reporting and ensures you maximize the stimulus although this isn’t necessary if you feel you are accurate with your RIR. I would aim for a 0-3RIR.

If you want to increase strength, performing more sets with lower rep ranges and higher intensities, would be better for strength gains than training to failure as it causes less intraset fatigue and loss of repetition velocity and intensity.

If you have both strength and hypertrophy goals, play it smart. Leg extensions and leg curls would be preferable lower body exercises to train to failure as they aren’t as fatiguing as compound movements such as the deadlift or squat. If you do want to train to failure on compound movements, save this for your last working set so you not to deter subsequent sets in the workout.

While it’s important to get close to failure or train to failure and there is no evidence I have came across to date which shows any dangers to this, it isn’t ideal to do for every set on every exercise. Training to failure is extremely fatiguing, and it could negatively affect subsequent workouts due to insufficient recovery. A Study by (Morán-Navarro et al., 2017) found that training to failure can increase recovery time by up to 24-48 hours.

I would say occasionally you want to train to failure in order to know your limits and what you are capable of. What it feels like to go to true failure as it will help you judge subsequent workouts using the RIR scale.

For athletes, training to muscular failure is not necessary, with similar strength gains even with 5RIR according to the research but with added recovery time.