Drawbacks and Risks of Failure Training

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If you take all sets to failure, you may experience physical and psychological drawbacks. To maximize your progress in the long-term, there are some factors to keep in mind:

Injury Risk and Overtraining

Injuries and overtraining are likely the most undesirable consequences of excessive failure training. 

Sets taken to absolute failure could result in technique breakdown, fatigue and possibly overtraining (3, 8, 18, 27, 29).

In the short-term, this is not necessarily a problem. However, if you are using this same level of intensity for every set on every exercise, you will likely run into long-term issues of aches and pains. You might experience serious injuries if form breakdown occurs under heavy loads and with compound movements.

For beginners in particular, this can have some very poor long-term consequences. 

If you are new to the gym, your primary focus should be on developing good habits and learning proper technique with a wide variety of movement patterns. If you are taking all of your sets to failure, your form is going to break down quickly and your recovery will be impaired. This is not ideal for future progression.

Psychological Effects

Related to this, training to failure promotes psychological fatigue, potentially reducing your adherence to the gym (23). 

While training “hard” is definitely still important for making gains, this does not mean that all sets have to be taken to absolute failure.

For most people, this is not a sustainable method of training, and as a result can quickly lead to burnout. You are much better off taking most of your sets close to but not all the way to absolute failure (3).

Remember, you can effectively recruit your muscle fibers without training to failure. This means you can still make strength and muscle gains without the negative psychological effects of failure training (49).

High Fatigue, Fewer Repetitions and Longer Recovery

Failure training leads to fatigue and longer recovery times between each gym session (3, 5, 23, 71). In addition, it’s well-established that failure results in fewer reps performed over multiple sets, greater muscle damage, and a larger decrease in performance in later sessions (5, 16, 29). 

Meaning that if all of your sets are taken to failure, you will get fewer reps on each set, and it’s going to take longer for you to recover between sessions. Ultimately, this could limit the amount of strength and muscle gains that you get in the long-term from your training program.

Given that training volume is a primary driver of muscle and strength gains (23), and failure training limits the amount of volume you perform over the course of a given workout, it stands to reason that a large amount of failure training in a program is not the most productive approach (3, 8). 

And as established in the previous section, most studies show similar gains between failure training to non-failure training protocols.

The limitations of the evidence

There is not much research directly demonstrating that training to failure increases your risk of injury or burnout (23, 27). This is mostly due to ethical reasons that do not allow for this type of research. We have based our conclusions on things that indirectly indicate burnout, such as longer recovery times, increased cortisol levels, greater subjective fatigue and so on.

When Should You Train to Failure?

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With the information presented in the last two sections, you may be thinking that you should never train to failure. However, there are situations where failure training can be a good idea.

Just like other training modalities, failure training has both its strengths and its limitations. It has some advantages when personalized and used in a strategic manner. 

Here are six examples of when it’s a good idea to take at least some of your sets to failure:

1. Your progress is slow and you train too light

If you are not making any progress in your training for either strength or muscle gains, it’s very possible that you are not training hard enough. While there are other factors that could be the reason (such as lacking proper nutrition and sleep), training hard is a requirement.

If you don’t know how hard you should be training, going to failure is a way to foolproof your set. 

Many people in the gym overestimate how many reps they have left, especially beginners (8). For this reason, it makes sense to experience what sets to failure feel like, if you are untrained.

Because of the potential drawbacks, you should not take every set to failure (23). Only if you are struggling to reach a high enough intensity in the gym.

2. You want to finish your workout quickly and still make progress

Training to failure can be useful because it makes your workouts more time efficient. You can do fewer sets and still see progress. 

A single set to failure can be sufficient for increasing both strength and muscle gains, although not to the same extent as multiple sets to non-failure (32, 62). Doing multiple sets for a given exercise is considered more optimal. This is because training volume has a dose-response relationship with gains (77). 

Example: High Intensity Training (HIT) HIT is a training strategy that uses low volume (few sets) combined with high intensity (heavy weights). A single set to failure can be surprisingly effective and efficient (1).

3. At the end of a training cycle

If you take all of your sets to failure at the beginning of a training cycle, you may end up overreaching quickly. It’s going to be hard to recover and continue making solid progress. You can be less worried about the negatives of training to failure when you have a deload/rest week coming up. 

One recent study showed merit to the idea of “delayed supercompensation”. Participants in this study experienced significant muscle and strength gains days after the conclusion of two phases of blood flow restriction (BFR) training (20).

While more research needs to be conducted on this topic, it seems plausible that an “overreaching” period may be a useful strategy to maximize gains before a recovery week.

4. You want to find your upper limit

Similar to the first recommendation, a lot of lifters simply are not sure if they are pushing themselves hard enough in the gym. Taking a set to failure lets you know where your limit is.

Keep in mind that for safety purposes, you should have spotters that can help you out if needed, especially on free-weight movements. Exercises such as the barbell squat and bench press can trap you when you fail the last repetition by yourself. 

In comparison, isolation and dumbbell exercises are less risky, and typically don’t require a spotter even when sets are taken to absolute failure.

5. You’re using a light weight for high reps (30+)

You can experience comparable muscle gains when using very low loads (i.e. 30 reps) and very high loads (i.e. 5 reps). Yet, training to failure (or at least very close to it) is required when using very light weights (23, 41).

As we discussed earlier, you need to train with a high level of effort when using low loads. This maximizes muscle fiber recruitment and muscle activation as explained with the size principle (50).

So while you can incorporate high-rep work into your training, make sure that you are taking sets very close to failure. 

6. You’re a highly trained lifter or bodybuilder

As you close in on your genetic ceiling, you may need to try different training methods. Failure training could provide a novel stimulus for muscle growth. Note that there is currently no research on this topic, so it remains speculative.

How to Use Failure Training in your Program 

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This section will focus on practical strategies for including failure training into your own program. To minimize the potential drawbacks, training to failure should be used with appropriate structure and planning.

Measure How Close You Are to Failure

Two scales exist that give you an objective measure of fatigue during each set. This way you can ensure you are actually training close to failure, and can determine how intense a given exercise is (8). 

Repetitions in Reserve (RIR)

The RIR system is a solid tool for gauging how close you are to failure. This scale accounts for variations in performance that occur on a day-to-day basis in the gym (8). As the name implies, it essentially refers to accounting for the number of reps “left in the tank” for a given set.

For example, if you perform a set of squats with 8 reps, but you could have done 2 more reps before reaching failure, then your RIR for that set would be 2. This can be applied to any exercise performed in the gym.

It’s important to get familiarized with the scale and make sure your sets are actually taken to absolute failure (when you are physically unable to perform any more reps). RIR is most accurate with high loads, and less accurate with low loads (high reps).

Rating of Perceived Exertion (RPE)

The RPE scale is more traditional, and has been used in both lifting and aerobic exercise. The scale uses a range of numbers to quantity how close you are training to failure. The RPE scale ranges from 1-10, with a great number representing a higher degree of intensity within a set (8).

For example, an RPE of 1 is a very light weight that requires little to no effort, while an RPE of 10 means that you could not perform another rep in the set or use more load (absolute failure). RPE is also related to RIR, as an RPE of 7 suggests that you could perform ~3 more reps in the set before reaching failure.

Rating of Perceived Exertion (RPE)	Repetitions in Reserve (RIR)
10	You have reached failure and can do no more repetitions. Zero repetitions in reserve.
9.5	You can do no more repetitions, but may be able to lift slightly more weight.
9	1 repetition in reserve.
8.5	1-2 repetitions in reserve
8	2 repetitions in reserve.
7.5	2-3 repetitions in reserve.
7	3 repetitions in reserve.
5-6	4-6 repetitions remaining.
3-4	You have many repetitions in reserve.
1-2	You have a large number of repetitions in reserve.

Table: Based on information from Zourdos and colleagues, 2016 (76)

Stick To Basic Exercises

Training to failure on machines or isolation exercises makes practical sense. Exercises such as bicep curls, calf raises, and shrugs use lower loads with simpler movements. They are generally safer and harder to get injured with.

Heavy compound movements such as the barbell squat, bench press and deadlift may be riskier to train all-out with. This is because training to failure results in a breakdown of form and proper technique, which can increase the risk of injury. 

Don’t Take Every Set To Failure

You should generally not take every set to failure. There have been both short- and long-term studies demonstrating that consistent failure training

• increases the recovery time of training, 
• leads to high fatigue 
• leads to psychological stress (21, 70, 71).

Additionally, training to failure reduces the amount of reps you can do per set, thereby reducing total training volume (27). One way to solve this is to reduce the weight you use between sets to maintain the same rep range (27). The other way is to only take the last set to failure. This way, you maintain your repetitions and avoid the pitfalls of excessive failure training.

Example: The Bench Press Let’s say you are doing the bench press and you perform 4 sets to failure with a spotter. On your first set, you perform 10 reps, which is your max (10RM). Because fatigue starts to kick in, in the following sets you then get 8, 6, and 4 reps. As a comparison, if you perform the same 4 sets with the same weight on the bar but this time train with 2 repetitions in reserve (RIR), your rep numbers across sets may look like 8, 7, 7, 6. While you got more reps on your first set when training to failure, you actually still ended up with fewer total reps across all 4 sets compared to the non-failure option. By utilizing an RIR/RPE system and training just short of failure, you still pushed yourself hard in the gym and provided an intense stimulus for both muscle and strength gains, but managed your fatigue better across each set and accumulated more training volume in the process.

Do It Towards The End Of Your Program

Let’s say you are beginning a brand new training cycle following a deload or recovery week. It makes sense to gradually work-up to failure training, by increasing the intensity slowly. 

The first week of a training cycle should begin at an intensity of ~3-4 RIR or ~7 RPE for most lifters, depending on their experience with training.

At this intensity level, you are still training with a high enough degree of effort to stimulate muscle and strength gains, but you are not accumulating a whole lot of fatigue in the process.

As the training cycle progresses, you can decrease your RIR by 1 each week to progress in intensity. Finally, in the last week before a deload, you can train at a ~0-1 RIR or ~9-10 RPE, which corresponds to failure or near-failure training.

In this example, notice that all sets are still done at a relatively high intensity level. Yet, they are  programmed so that you manage the amount of stress you are experiencing. 

It can be tempting as a lifter to train all-out in every set. If you have the goal of managing recovery and maximizing gains in the long-run, being forward-thinking about your training goes a long way in avoiding both physical and mental burnout. 

Use Failure Techniques

AMRAP sets

AMRAP stands for As Many Reps As Possible. It means you lift a weight until you have zero repetitions in reserve and reach failure. The most basic form of failure training is the AMRAP set. These sets are a good way to measure progress.

Let’s say you can do a maximum of 10 repetitions at 100 kg (220 lbs) on the bench press. If you train for a while, and then test your max reps again (AMRAP), then you might be able to do 14 reps. 

Your AMRAP progress is therefore 4 reps at 100 kg / 220 lbs.

Drop sets

Drop sets are a time efficient way to make progress with failure training.

Here’s how to do a drop set:

• Step 1: Lift a weight until you reach failure
• Step 2: Immediately reduce (“drop”) the weight by 10-30%
• Step 3: Repeat 1-3 times

The key is to not take breaks between the sets. Your goal is to do 2-4 drop sets in a row. You are in other words doing multiple sets to failure, then reducing the weight so you can still maintain your repetition goal. If you do drop sets without reducing the weight, you would have to do fewer reps for every new set.

It is easy to do drop sets on machines (“up the stack”) or with dumbbells (“down the rack”). That way, you can reduce the weight quickly and safely. Doing drop sets with the squat or bench press can be ineffective, as you need to spend time taking weight plates off. Alternatively, you can use spotters that help you remove plates quickly. Take care that you do not rush, and maintain proper form.

Note that drop sets can be harmful if done excessively. 

Blood flow restriction training (BFR)

BFR is a technique where you use very low resistance for an exercise while cutting off blood flow to the muscle.

This is a useful method for people who prefer training with very high repetitions or simply cannot use heavy loads (i.e. if you’re injured). Typical muscles that are used for BFR training include the quads, biceps, and calves, since they are easier to restrict. You cannot target the muscles of the torso with BFR. 

Research has demonstrated that when sets are taken to muscle failure, BFR and low-load training are equally capable of inducing muscle growth (10). Even in trained individuals, low-load training with the addition of BFR can increase muscle size (11).

Another appealing aspect of BFR training is its effects on fatigue and soreness. Some studies have shown that BFR training results in a reduced perception of RPE, soreness, and discomfort compared to normal training (12, 13).

Here are some practical ways to use blood flow restriction training. The infographic is created by Adam Virgile and based on the work of Brad Schoenfeld:

What Does “Training to Failure” Mean?

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Technical failure vs. absolute failure

There are two main types of failure training. In most studies, training to failure is referred to as absolute failure. This means you take sets to the point where you can’t perform another repetition (23, 24).  

In comparison, a lot of people in the gym take their sets to technical failure. This type of failure  means you can’t perform another repetition without breaking proper form. A good example of this is performing the bench press without a spotter. You stop the set at 9 reps because you can’t do the 10th rep properly. 

Concentric vs. eccentric failure

For every lift you do, there are two phases: 

• The concentric phase is when the muscle shortens. For example, when you push the weight in a bench press, your triceps and pectorals shorten. Another example is when you pull your body to the bar in a pull-up. Then, your biceps and lats shorten.
• The eccentric phase is when the muscle lengthens. It’s when you let the bar go down to your chest, or when you lower your body in a pull-up. 

You can reach concentric failure, but still do more eccentric reps. The reason is that we are generally stronger in the eccentric phase. Oftentimes you fail an exercise concentrically before eccentrically. In the pull-up example, you can fail to pull your body up, but still be able to lower it from the top position.

Reflections on the Scientific Literature

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In this section, you can read our thoughts on the strengths and weaknesses of the failure literature. 

The strengths of the literature

Similar participant demographics

In most of the studies, the participants were 20-29 years old and had normal body weights. The benefit of this homogeneity is that studies can be compared directly. Notably, the results from these studies only apply to this particular population. We should not assume that the conclusions of our article apply to obese older adults.

Appropriate strength and hypertrophy measurements

Most studies used one repetition maximum test to evaluate strength. This is the gold standard of strength testing, and it is used in competition, research, and in training.

The studies that evaluated muscle hypertrophy looked at muscle cross sectional area or muscle thickness. These were normally measured by ultrasound and/or MRI, which are usually considered the gold standard of testing.

Study design: randomized controlled trials

15/18 studies with data on strength or hypertrophy were randomized, controlled trials. The other three were crossover studies. On the hierarchy of scientific evidence, these types of studies are weighted higher than non-randomized or non-controlled methods.

The most common study limitations

This is an overview of common limitations. We ask that you not reject the literature due to these limitations. Every study has limitations, regardless of how well designed it is. 

Lack of volume matching

Volume matching means that each group in a study is performing the same number of total sets or they have their repetitions matched across each set. This is crucial because we know that total training volume drives muscle and strength gains, given that sets are pushed close to failure (23). If one group is performing more sets and reps than another group, they will likely see greater gains.

Five out of the 18 studies with data on strength/hypertrophy did not match volume between the failure group and the non-failure group. Since training volume is key to making progress, this is a big confounder. In our analysis, we made sure to give less emphasis to the studies without volume matching. 

Did subjects train equally hard?

It is challenging to standardize failure and non-failure training. Failure training will naturally lead failure groups to train harder than non-failure groups. In untrained populations, beginners may underestimate their training intensity. So if beginners are asked to train two repetitions from failure, their lack of experience may make them train four to five repetitions from failure. Thus, their sets become very easy.

Study length

The average study lasted for 10.2 weeks. This duration may be enough to detect differences in strength and muscle mass. Yet, if the differences are small, then they might not be detected statistically at 10 weeks. Many of the studies had null findings, no differences between groups. Was this because there truly is no difference, or because of the study duration?

Limited ecological validity

Several of the studies used unilateral knee extension as the primary training method. Every participant trained one leg to failure, while the other leg trained to non-failure. Then, the failure legs were compared to the non-failure legs. 

This method has three issues:

The first issue is that only one exercise is performed. Hence, the results apply to this exercise alone. If participants were to train their entire bodies to failure, we may see different results. 

The second issue relates to the use of unilateral training. Would the results of a study be the same if both legs trained to failure, or not? 

Third, there is the “cross-education effect” where strength increases in one limb affect the other. This has only been shown in untrained control limbs, and may not be an issue when both limbs are trained.

Convenience sampling

As with most training studies, the participants were recruited through convenience sampling. This type of sampling method uses participants “simply because they are "convenient" sources of data for researchers” (75). 

An example of convenience sampling is to stand outside the library and ask bypassers to answer a questionnaire. This is a convenient way to find participants, but they are not randomly selected from the population. This raises concerns of representativeness.

Sci-Fit’s Research Methodology

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How we researched the topic

Systematic search strategy

We researched failure training using the following databases: Pubmed and Europe PMC.

We used the following search string: ("resistance training" OR "strength training" OR "resistance exercise") AND ("concentric failure" OR "momentary muscular failure" OR "MMF" OR "repetitions to failure" OR "muscle failure" OR “volitional failure” OR “task failure”) AND (“hypertrophy” OR “strength” OR “muscle mass” OR “lean body mass” OR “LBM” OR “gains”).

Date range: we included all studies that were published up until 27.08.2020.

We reviewed the references of included studies to identify more studies. Additional studies were found in the “similar articles” section on the journal websites.

Outcomes

The primary outcomes we assessed from the available studies were the comparison of failure vs. non-failure training on muscle hypertrophy and strength.

Additionally, our secondary outcomes included a comparison of failure vs. non-failure training on injury risk, fatigue, recovery from training, exercise technique, psychological stress, and its impact on BFR training.

Inclusion criteria

Studies that were included in our analysis had to meet all of the following criteria:

1. Were carried out in humans
2. Subjects ranged in age from 18 years or older
3. Subjects performed a resistance training intervention
4. Was a narrative or systematic review of failure training or an experimental study comparing failure vs. non-failure training
5. Assessed any of the primary or secondary outcomes

Exclusion criteria

Additionally, studies from our systematic search were excluded for any of the following reasons:

1. Consisted of animal, in vitro, disease or case studies
2. Had fewer than 10 participants
3. For experimental trials investigating primary outcomes: duration shorter than 2 weeks

Study inclusion and data extraction

The systematic search yielded 768 studies. 63 studies were included after first-pass exclusion. These studies were scanned and 13 additional studies were extracted from the references. A second-pass exclusion was performed and 7 studies were removed. 

This left us with a grand total of 73 included studies for the review.

18 studies had data on the primary outcomes: strength and hypertrophy.

55 studies had data or discussion on the secondary outcomes: injury risk, fatigue, recovery, exercise technique, and blood flow restriction.

Data and quotes were extracted from the study full texts and double-checked. Five studies and one review were selected for in-depth analysis. Data extracted included: study type, participants (N), age, gender, body weight, training status, training protocol, strength and hypertrophy measurement methods, and results for strength and hypertrophy. Quotes were extracted for all primary and secondary outcomes.

Review

The article was reviewed for scientific accuracy and rigor by Brad Schoenfeld, PhD.