Geschatte leestijd: 5 minutenPre-Exhaust, or “voor-vermoeien,” is a technique that bodybuilders often use to achieve better results. Over the past decade, two studies have been conducted on this method. The conclusion of both studies was that pre-exhaust does not work. In this article, I will explain what pre-exhaust entails, why bodybuilders believe it should work, and how the mentioned studies, contrary to their own conclusions, actually support this theory.
What is the idea behind pre-exhaust?
Many strength athletes prefer compound exercises that involve multiple muscle groups over isolated exercises targeting one muscle group. Compound exercises engage more muscle groups simultaneously, activating more total muscle mass and consequently increasing the production of hormones such as growth hormone and testosterone (1,2). For strength athletes like strongmen and powerlifters, it is also important that all relevant muscles learn to work together as efficiently as possible for better performance.
However, when the goal is purely muscle mass, the last reason for compound exercises is no longer applicable. The aim is not to lift or move as much weight as possible, but to load the muscles as heavily as possible to induce the damage that leads to muscle growth. For muscle mass, you also want to maximize the production of growth hormone and testosterone, so compound exercises are a “must” even for those focusing on mass. However, the downside of compound exercises is that the targeted muscles may not always be fatigued first.
Pre-exhaust aims to fatigue the desired muscle group the most during compound exercises, rather than one of the other muscle groups involved in the exercise. Pre-exhaust ensures that during compound exercises, the desired muscle group (relative to the maximum load) is most heavily loaded by fatiguing it first with an isolated exercise.
Explaining pre-exhaust with a practical example
For example, when training your quadriceps by squatting, you also use other muscles such as those in the lower back, buttocks, hamstrings, and abdominal muscles. However, you want to ensure that at the end of your set, you have trained your quadriceps to the maximum and have not stopped earlier because, for example, your lower back could not continue.
Pre-exhaust addresses this by, for example, first performing leg extensions. In this isolated exercise, the ratio between the load on the quadriceps and other muscles is much greater than in squats. After completing the leg extensions, the quadriceps are much more fatigued than the other muscles. When you then squat, the likelihood of other muscle groups fatiguing earlier is much lower. As a result, the quadriceps are driven to their maximum much faster and do not have to stop earlier due to another “weak link.”
Note! This is mainly about the relative load on the muscles compared to their maximum load, not the level of activity.
Pre-exhaust contradicted by researchers who misunderstand the theory
Both in 2003 and in 2007, studies were conducted whose conclusion was that pre-exhaust does not work (3,4). Below are the quoted conclusions. The astute reader will, after reading the above explanation, already see where these researchers’ assumptions go wrong.
“Our findings suggest that performing pre-exhaustion exercise is no more effective in increasing the activation of the prefatigued muscles during the multi-joint exercise.”
-P. Gentil, College of Physical Education, Catholic University of Brasilia
“Our findings do not support the popular belief of weight trainers that performing pre-exhaustion exercise is more effective in order to enhance muscle activity compared with regular weight training. Conversely, pre-exhaustion exercise may have disadvantageous effects on performance, such as decreased muscle activity and reduction in strength, during multijoint exercise.”
-J. Augustsson, Department of Rehabilitation Medicine, Göteborg University
In both studies, an isolated exercise was performed before a compound exercise. In one case, leg extensions before leg press. In the other case, chest exercises Peck Deck Flyes before bench pressing. In both cases, it was found that the “target-muscle,” the muscle group primarily targeted by the exercise, showed less activity during the compound exercise when an isolated exercise was performed first. The researchers see this as a reason to argue that pre-exhaust does not work. However, I see this as support for the theory that pre-exhaust works and for my personal theory that sometimes researchers fail to understand the theory before attempting to prove its validity.
The researchers observed that, for example, the quadriceps showed less activation after performing the leg extensions (measured by EMG). They also observed that other involved muscles (synergists) showed more activity. They therefore rightly assume that these synergists take on a greater share of the load from the quadriceps. Because the quadriceps show less activity, they conclude that the training is less effective for the quadriceps.
However, the crucial point is to overload the quadriceps. To push them to their maximum and beyond to stimulate muscle damage and growth. The fact that other muscles start to contribute more while the quadriceps contribute less indicates that this point of overloading the quadriceps has been reached or exceeded! The researchers rightly point out that performance during compound exercises deteriorates due to pre-exhaustion. This is correct and logical; after all, the most important muscles have already been pre-fatigued.
The mistake the researchers make is assuming that pre-exhaustion is aimed at improving performance during compound exercises and increasing activation/load on the “target muscles.” The performance is the muscle growth achieved as a result, not how much weight can be squatted. Unfortunately, there is no research yet on the effects of muscle growth after pre-exhaustion, so its effectiveness has not been proven.
How they arrived at this wrong objective is unclear. Since the true purpose of pre-exhaust is well known in the bodybuilding world, it is a mystery which trainers are meant by the phrase: “the popular belief of weight trainers that performing pre-exhaustion exercise is more effective in order to enhance muscle activity.”
It seems as though the researchers confuse the concept of pre-exhaust with Post Activation Potentiation (PAP). This theory will be the subject of my next article.
“Weight is not important”. Use pre-exhaust even if it means squatting less
You often hear bodybuilders say, “Weight is not important.” This saying assumes exactly the distinction I make above. It is not about how much weight you can lift, but how heavily you have to load your muscles for it (relative to their maximum load). However, many struggle with this concept. “Ego-lifting” is common in strength training, lifting heavy weights at the expense of technique and effectiveness to show everyone how strong you are. It will be the same vanity that motivates bodybuilders to put in the necessary effort in training and nutrition that leads them into this pitfall.
Pre-exhaust means that you can lift less weight during your compound exercise. These compound exercises are often the flagship exercises of powerlifting such as squats, deadlifts, and bench presses. These are the exercises many people know by heart how much weight they can handle. Pre-exhaust sacrifices performance in maximum weight for gains in muscle mass. Therefore, many do not like pre-exhaust because it makes them seem weaker. However, this reason is just as valid as the reason some people have to only lower the bar halfway during bench press and do half squats to appear stronger.
So, don’t let that be an excuse, and don’t be afraid to try the principle of pre-exhaust.
References
- Walker, S., Taipale, R. S., Nyman, K., Kraemer, W. J., & Hakkinen, K. (2011). Neuromuscular and hormonal responses to constant and variable resistance loadings. Medicine and Science in Sports and Exercise, 43(1), 26-33
- Smilios, I., Pilianidis, T., Karamouzis, M., & Tokmakidis, S. P. (2003). Hormonal responses after various resistance exercise protocols. Medicine and Science in Sports and Exercise, 35(4).
- Augustsson J, Thomee R, Hornstedt P, Lindblom J, Karlsson J, Grimby G. Effect of pre-exhaustion exercise on lower-extremity muscle activation during a leg press exercise. J Strength Cond Res. 2003 May;17(2):411-6.
- Gentil P, Oliveira E, de Araújo Rocha Júnior V, do Carmo J, Bottaro M. Effects of exercise order on upper-body muscle activation and exercise performance. J Strength Cond Res. 2007 Nov;21(4):1082-6.
