Written by: Brian Henneberg, Physiotherapist

In the old days, when no one in the world of training gave anything for research-based knowledge about training, there was a man named Joe Weider who made a system.

He called it the Weider System of Bodybuilding. Joe Weider was a bodybuilder, businessman, fitness expert, and Arnold Schwarzenegger's spiritual father. He was a fascinating character, and this article is about the Weider system he created.

Joe's method contains almost nothing he devised himself, but what he did was gather diverse bodybuilding techniques, name them, define them, put them in a system, and make them available to bodybuilders and fitness enthusiasts worldwide. As a result, he has published a variety of books and training videos in addition to his bodybuilding publications.

Let's study why some of Joe Weider's old training principles work.


Back-off set

The back-off term is a technique where you do one (or sometimes several) sets of lighter weights after finishing your 'main set' with heavier weights. Studies have shown that adding a single back-off set to a strength program resulted in more muscle growth, an increase in 1RM, and increased muscular endurance. 

Back-off sets are likely beneficial because they can increase total volume and increase the number of repetitions that stimulate muscular growth. On the other hand, back-off is most effective when performed after a strength-based workout (between 1-5 repetitions with heavyweights, to failure).

Drop sets, also called descending sets

Drop sets are comparable to back-off sets. However, you'll probably do more drop sets than back-off sets, and the intensity (heavyweights) will almost always be higher with back-off sets, but RPE is usually higher with drop sets, i.e., one drive to failure. In addition, drop sets are typically used in smaller (isolation) exercises, whereas back-off sets are used more in extensive exercises like squats and deadlifts.

Drop sets, in which you perform three sets of 10-12 repetitions to failure with no rest between sets but slightly reduced weight on sets 2 and 3, appear to provide the same amount of muscle growth as three typical sets of 10-12 reps with 90-120 seconds pause between sets.

Drop sets, also called descending sets

If we look for another reason, multiple studies show that training with very light weights when pushed to failure enhances recruitment and load on growth-enhancing anaerobic type 2 muscle fibers by increasing fatigue of already recruited muscle fibers.

This activation of muscle fibers happens by metabolic load but can also be because of fatigue mechanisms. Fatigue appears to affect muscular activation and thus muscle growth and strength.

This theory from a study in 2016 (https://pubmed.ncbi.nlm.nih.gov/27174923/) showed that training with light weights to exhaustion significantly increased muscle mass and strength as training with heavyweights. Therefore, the best theory we have now is that drop sets are beneficial because of rapid fatigue. 

Also, because of a significant degree of muscle activation, even in a shorter time than when running more traditional sets (you see a similar effect in occlusion training ).

Forced reps

Forced reps involve executing a standard set, but instead of putting the weight away after hitting your repetitions, you have a spotter helping you get more repetitions in. Forced repetitions have brought very little research, but the logic for why they should be a successful approach must be based heavily on purpose for using drop sets, namely muscular fatigue.

Strip set

Strip set

A strip set is when you do a standard set and use a spotter to take weights off the bar as you approach failure. It allows you to continue firing reps. It is very similar to drop sets, but is used primarily on more extensive barbell-based exercises, where it is not easy to reduce the weight yourself quickly. Again, it increases the volume and fatigue and adds more stimulating reps to the set.


Rest-pause is a technique where you do an utterly standard set to failure. Then take a short break of 10-20 seconds and do some extra reps with the same weight. It's repeated several times, most often twice, after which the set is finally over. The difference between the rest-pause and the other methods we have looked at is that you do not reduce the weight when you run the rest-pause but continue with the heavyweights.

Partials or partial reps

In a biceps curl with full ROM (range of motion), you will go from 0 degrees (full stretch) to 120 degrees (full bend), while during the Joe called partial reps, you will run with a limited range of motion, from, e.g., 45 degrees to 90 degrees.

Whether partials are effective or not depends on which muscle one is training. The triceps look, e.g., and respond well to partials ( https://journals.lww.com/nsca-jscr/Pages/default.aspx?PAPNotFound=true ), while the thigh muscles seem to respond better to full ROM. 

Whether partials are effective or not seems to depend on which muscle one is training. The triceps looks e.g. seems to respond well to partials ( source ), while the thigh muscles seem to respond better to full ROM. The biceps is located somewhere in the middle, while not much research has been done on other muscles.

The research shows that the theory that partials should provide a superior squeezing of the blood circulation, seems to hold water, but whether it also results in a superior growth response, thus seems to depend on which muscle group you train.


Burns is another one of these fatigue techniques where you do a few more reps after your regular set, generally with a limited range of motion, until you're completely exhausted (hence the name burns because it burns in the muscle). Again, it will result in a high level of exhaustion while also increasing your pump.

The PUMP is a fluid tension in the muscular tissue that happens using burns, partial reps, forced reps, strip sets, drop sets, and partially rest-pause exercises.

Techniques that do not appear to be effective

However, not all of the techniques that Joe collected, named, and put into system are effective. Let's just take a few of them that you probably do not have to deal with.


Pre-exhaustion (pre-ex) is a technique where you try to exhaust the large muscles, with smaller exercises, before embarking on a large exercise. It can e.g. be pecs that one tries to exhaust with cable flyes before embarking on bench press. The rationale behind the use of pre-ex should be that when the big muscles (like pecs) have been run tired through an isolation exercise (like cable flyes), and then then exposed to a big exercise (like bench press), then the pecs are shot through. something so emphatic because they are exhausted in advance and now feel the wrath of fresh triceps and front delts that can push lots of reps out.


However, there are certain problems with this theory, as the activity in pecs actually seems to decrease when running bench press with exhausted pecs and fresh triceps and shoulders. This has been seen in e.g. Soncin et al. 2014 , when the shoulders became more active and pecs became less active when pecs were tired.

Some believe pre-exhaust is more about exhaustion and not increased muscle activation. But whether the exhaustion stems from small exercises followed by large exercises, or more traditional heavy training with the large exercises first, it immediately seems a bit hip as hap. The research that is available also points in the direction that there is probably not much difference when it comes down to it.

If the goal is just exhaustion, then the question is also whether pre-ex is not just a cumbersome version of something that is much simpler to do in other ways, e.g. through some of the above techniques, which focus on exhaustion. Then you at least avoid having to decide which muscles you think are primary secondary and tertiary in a given exercise, and which in that case must be exhausted first.

The circulation principle

One of the more silly principles in Joe's system is what he called The circulation principle, which was that, in the same training session, you should preferably train muscles that were close to each other, so as to keep the blood circulation to one part of the body. It gave the best gains one would think. You can not expect the body to effectively build muscle tissue in your arms if you train at the same time, so the blood must also go all the way down there. Dummy.

The circulation principle

This principle does not seem to have many supporters left. I think the bodybuilders underestimated the body's ability to regenerate a bit. It is a bit like taking a knife and making a scratch in one of your forearms. It then takes maybe a week for the body to heal the wound up again. If you then make a scratch in one arm and on your calf at the same time, the healing time is suddenly reduced by half, because the blood has several tasks far apart. It's some nonsense.

The pervasive feature

As can be seen from the techniques that seem to be evidence of the effect of, the common feature of many of them is that it is about exhaustion and pumping. When so many bodybuilders over so many years, have used so many techniques that are basically very similar to each other, then it could indicate that there is something or other that must work. And parts of it are gradually backed up by the professional knowledge.

Unfortunately, Joe's influence was so great that people patched it all up and made Joe's principles law. Also that of what was some worse nonsense. But luckily, there were also gold nuggets in Joe's theft-stolen principles.



J Strength Cond Res. 2004 Nov; 18 (4): 730-7. Muscular adaptations to combinations of high- and low-intensity resistance exercises. Goto K1, Nagasawa M, Yanagisawa O, Kizuka T, Ishii N, Takamatsu K. https://www.ncbi.nlm.nih.gov/pubmed/15574075

Morton RW, Oikawa SY, Wavell CG, Mazara N, McGlory C, Quadrilatero J, Baechler BL, Baker SK, Phillips SM. Neither load nor systemic hormones determine resistance training-mediated hypertrophy or strength gains in resistance-trained young men. J Appl Physiol. 2016 May 12: jap.00154.2016. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/27174923

Rafael Soncin, Juliana Pennone, Thiago M. Guimarães, Bruno Mezêncio, Alberto C. Amadio and Júlio C. Serrão. Influence of Exercise Order on Electromyographic Activity During Upper Body Resistance Training. J Hum Kinet. 9 Dec 2014; 44: 203–210. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4327372/

Goto, Masahiro; Hamaoka, Takafumi; Maeda, Chikako; Hirayama, Tomoko; Nirengi, Shinsuke; Kurosawa, Yuko; Nagano, Akinori; Terada, Shigeru. Partial range of motion exercise is effective in facilitating muscle hypertrophy and function via sustained intramuscular hypoxia in young trained men. Journal of Strength & Conditioning Research: Post Acceptance: June 02, 2017



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