Is working out until you can’t work out anymore a good or bad thing? We look at the science of muscle soreness and muscle failure
Muscle Soreness and Muscle Failure
This is part 2 (part 1 here) of Training to Failure – in layman terms… working out until you cannot workout anymore
Context has the final word once again.
Muscle Soreness and Muscle Failure – What Does the Science Say?
Scientific studies have attempted to compare failure and non-failure training and some have done a reasonable job at it.
I won’t slam you with a thousand study references but up until now the picture has looked something like this:
Not everyone is great at judging how close they are to muscle failure, so training to failure is a guaranteed way to ensure you are working the muscles hard enough to elicit growth.
Chronic failure training – as in, going at it every time you hit the gym – however, can cause fatigue which can hinder your overall effort and possibly dull growth.
Failure training is no more dangerous than non-failure training provided any potential problems are mitigated. In other words, it’s not inherently dangerous to train a muscle to failure, but falling over while squatting to failure is (okay that last bit wasn’t sciency).
Some studies have even completely contradicted each other in the past, where one says failure training produces better results while another concludes that it hinders progress.
So, what are we to think from a scientific standpoint?
Recently, a comprehensive study was undertaken.
Over the course of 20 weeks, 10 different training protocols – each one a unique combination repetition design – were performed by the subjects.
Muscle damage and fatigue were measured before each training session and at intervals afterwards, ranging from 6 hours to 48 hours post-workout.
Subjects performed 3 sets of bench press followed by squats. The rep protocol included 5 failure and 5 non-failure designs of different rep counts. The non-failure protocols also ranged in RPE (rate of perceived exertion).
For example, in the failure group, one subject would do 12 reps where 12 were possible. That would be a failure set. This went all the way down to a failure set 4 reps where only 4 were possible.
In the non-failure group, one subject did 6 reps where 12 were possible, another did 5/10, and so on down to one subject doing 2 reps where 4 were possible.
Intensities (weight) was matched to the RPE and rep counts.
The results of the study were as expected, but it’s nice to have a quality investigation say as much.
High rep failure sets – particularly 10 to 12 reps – take longer to recover from than sets at 5 to 8 RPE.
Again, that sounds obvious but when you consider that the scientists measured actual physical performance as a follow-up at 6, 24 and 48 hours it bears significance that the higher-rep failure guys had reduced power compared to the non-failure subjects.
So, with that in mind, the longer recovery time could definitely impinge on volume, and therefore gains.
The study shouldn’t be interpreted as saying never do failure sets, but it was the first one to show the recovery over time following failure versus non-failure training and with different RPEs and rep counts to boot.
What would be great to see now is what recovery and progress can be made from 5, 6, 7, 8 or 9 RPE where repetitions are equal and resistance (weight) is the variable.
Training Experience and Muscle Failure
Something I’ve heard a lot is that over time, you have to train to failure more and more to continue seeing progress.
This is generally from people who have been lifting for years, perhaps 10 and over. They are talking about a widely held belief that adding muscle mass and/or making strength increases becomes that much more difficult as you become more and more experienced.
Of course it’s true. The most successful bodybuilders in the world cannot make the same gains as someone who is 6 months into regular lifting.
Training to failure appears to be synonymous with that “extra” that veteran bodybuilders are referring to.
We can’t really look at scientific data and make any meaningful conclusions in the context of lifetime lifters.
At least, I don’t know of any studies that have been able to get guys with a decade or more experience busting iron.
For one thing, the diminished returns from their training would make it very difficult to measure anything in a reasonable amount of time.
So does experience dictate how much you should train to failure? Probably, but I can’t put numbers on it.
A pro bodybuilder probably mixes it in with non-failure training in a way that’s optimal for them as an individual in terms of recovery.
These people are at the apex of their potential for muscle gains and so squeezing fractions of improvement out of their already sculpted muscles probably takes some extreme work.
For regular human beings, experience will matter but then so will individual responses to resistance training.
I know some people who can’t move the day after a gruelling leg workout and others who are back at the gym squatting.
This could be partly due to individual biochemical responses to training, but it can also be because of individual perceptions of effort.
Muscle Soreness and Muscle Failure – Varied Perception of Effort
We’ve established what muscle failure is and it’s pretty easy to understand when you’re lifting weight.
What’s perhaps more difficult is an individual’s perception of how close they are to that muscle failure. Are they 2 reps away from failure? Or is it 3…4?
Some of us are better at it. Since it’s becoming fairly clear that we shouldn’t train to failure every time we train, due to the lengthy recovery process and the potential decrease in performance and volume, how close should we get?
It’s a good question, and one that’s often answered with: go with how you feel.
If you training program is of decent design then your overall volume – provided the intensity is adequate – is the most important factor for progress.
Once you are lifting considerable percentages of your 1RM (i.e. 60% and above), total volume is important.
Volume can be measured in total weight lifted as well as number of sets performed.
If your 1RM on benchpress is 275 lbs then if you take 70% of that and 90% of that you can still perform the same volume with 70% as you do with 90% but your likely to be much less fatigued.
That isn’t to say you should always stick to 70% of your 1RM, the point is more about related to being able to achieve your program’s volume by making the right decisions.
Perhaps later in the week, or on your last session of that exercise before you have a couple days off, you can do some failure sets.
Muscle Soreness and Muscle Failure – Leaving No Doubt
I mentioned earlier in the article that this might be the best reason to train to failure.
Taking the muscle to failure leaves no doubt as to how close you have got to maximal motor unit output and muscle fiber recruitment.
In the very least, it reassures you that you couldn’t have done more even if you tried.
Once again, if you are approaching your total volume for that muscle or muscle group for the week then it won’t hurt to use it.
How Much is Too Much?
I would say if your first sets of a training session are difficult or painful to get through because of residual fatigue/soreness from the previous session, you are overdoing it.
Actually, if it occurs over a sustained period of time, it’s a good sign that you are overtraining in general, along with other indicators like declining performance, psychological distress, sleep disturbance, lack of motivation, deteriorating physique
I and many people have found that soreness level and the length of time it sticks around are great indicators of how suited a program design is to the individual using it.
In my opinion the larger compound lifts like squats and deadlifts shouldn’t be taken to failure often, if at all.
These movement rely on so many muscles and muscle groups that working them to that point is likely to result in your form slipping, and yes, possible injury.
What’s more, given the stress these lifts place on the central nervous system (CNS), particularly the closer you get to maximum single repetition loads, working to failure can have detrimental effects that go beyond the musculoskeletal system.
Muscle Soreness and Muscle Failure – Single-Joint Movements
The single-joint movements, machine and cable exercises are more suited to putting in maximum effort. Once you’ve finished your free squats, for example, taking your legs to the pain cave on the leg press isn’t a bad thing – again, so long as the rest of your training doesn’t suffer.
By no means is it necessary or even advantageous to train to failure every time you go to the gym. Employed correctly it can be a useful addition to your program.
There are lots of options open to you as well. No-one is telling you (they shouldn’t be anyway) to do a specific number of sets to failure within a workout.
People often use it on their last set of a particular exercise. They might even combine it with a big drop set where they reduce the weight by about 30% after reaching failure and then go again, repeating the process once or twice more.
Going Beyond Failure
Muscle failure doesn’t even stop some people. They go beyond that point by performing spotter-assisted repetitions; forced and negative reps.
Forced reps are those which a spotter helps you complete after you have reached the point of muscle failure on your own. It’s a bit like reducing the weight but without even the pause it would take to do so.
Negative reps also require a spotter, and sometimes more than one.
These are traditionally done with weight that is heavier than the lifter can actually lift with the concentric – or positive – portion of the repetition.
It works after concentric failure as well because it’s more or less the same thing. The spotters help you lift the weight on the positive and then allow you to perform a controlled negative.
Either one of these options are ways by which you can go deeper into the pain cave. The value of them can be debated all day long, as can regular failure sets.
Main Takeaway Points
I think the moral of the muscle failure story can be summed up with the following points:
Training to failure is relatively safe, provided it does not lead to dangerous practices (like back squatting to failure away from the power rack).
It is not, however, essential to make muscle growth gains, neither is it fore strength improvements – at least not in the first few years of training.
Including some failure sets will help guarantee you are recruiting maximum motor units and muscle fibers, but this can probably also be achieved if you leave a couple reps in the tank provided you have an accurate perception of how many you have left.
Too much failure training will inhibit your ability to complete weekly volume, which is arguably more important for progress than failure sets anyway.
Strategic timing of failure sets – such as in the last few sets of your weekly volume, or before a couple days rest will help limit any negative impact they have on your overall volume and frequency
Closing Remarks on Training To Failure – Muscle Soreness and Muscle Failure
If you’re befuddled by the amount of information coming at you and you’re still not sure whether failure sets are good for your gains or not then join the club.
No-one can tell you for sure, but the science is getting better at zeroing in on the issue.
Research, bro-science, anecdotal evidence, observations, and whatever else has issued from the mouths of the wise and weird, has shown that muscle failure still has a place in a rounded training program.
Some scientists found that it enhances the production of growth hormone following a workout. Other studies show a benefit in terms of hypertrophy.
Bodybuilders have done it for years, and given the literal weight of their opinion, you’d be hard pressed to tell them they are wrong.
And if nothing else, sometimes smashing an exercise until the muscle is well and truly murdered…well, it just feels right.
Plus, the pump you get is outrageous.
Modern research is leaning more towards the opinion that it’s almost redundant, especially if it negatively affects your overall training volume…but they also say you might want to add some in just in case, you know, to make sure you’re pushing your muscles as much as you think you are.
Thankfully, there’s nothing specifically saying failure sets are useless or dangerous.
So have at it, but remember this: the deeper you go into that pain cave, the longer it takes to find your way out afterwards.
Don’t overdo it, otherwise you’re just wasting time and energy, and that’s something none of is can afford.