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Dual Factor Hypertrophy Training



Aug 11, 2010
Dual Factor Theory - Fitness Training Routine Guide

The Dual Factor Theory, also called Fitness Fatigue Theory is somewhat more complex than the Supercompensation Theory. The theory is based on the fact that and individual's fitness and fatigue are totally independent of each other. This theory is entirely dependant on one's base conditioning (or physical preparedness or fitness). The thing is, when you have a high level of fitness (or conditioning/ preparedness) this level changes fairly slowly. This is because over the short term fitness does not fluctuate often. (However, fatigue can change (increase or decrease) fairly quickly when compared to fitness).

"The theory works like equilibrium in that training will have an immediate effect on the body (similar to supercompensation). This effect is the combination of fatigue and gain (again, remember the equilibrium thing). So after a workout, because of the stimulus that training provides, preparedness/conditioning/fitness increases (gain) but at the same time will decrease due to fatigue from the training."

"So, the outcome of the training session is the result of both the positive and negative consequences of the training session. These two outcomes depend on time. By striking the correct balance, fatigue should be large in extent but short in how long it lasts. Gain on the other hand should be moderate, however, and is longer in duration. Typically the relationship is 1:3, if fatigue lasts x amount of time then gain lasts 3x amount of time."

"Given the two factor theory, which separates physical fitness or preparedness and fatigue, you see that the timing of individual workouts is unimportant to long term gains (unlike Supercompensation)... in other words regardless of whether or not fatigue is or is not present, fitness can and will still be increased" (which is the goal)...

So what you get concerning the two-factor theory is a period of peaking fatigue (maybe 6 weeks),followed by a period of rest (maybe 2 weeks deloading, then one or two weeks of total rest). You view entire weeks and maybe months, as you would have viewed just one workout with the single factor theory. For example, in the single factor theory, one workout represents a period of fatigue. But, in the two-factor theory, 6 weeks would represent a period of fatigue. In the single factor theory, a day or two (up to a week) represents a period of rest. But in the two-factor theory, up to four weeks may represent a period rest.

"What is important to note is that there is almost universal agreement among scientists and athletes and coaches in all sports EXCEPT bodybuilding that the two factor theory is correct and the single factor theory is not correct and is in fact suitable only for beginners to follow when planning training."

"It is also important to note that most athletes in most sports are experiencing some level of constant fatigue ALWAYS, except for maybe a couple of weekends a year, when they are peaking. Training takes place daily against a backdrop of fatigue". Therefore, you should be able to see why, concerning the single factor theory; it would be very hard to ever fully recover, unless you sat on your ass for two weeks and did nothing."

Applying it to the real world

When setting up dual factor periodization for the bodybuilder, it is important to remember to plan for periods of fatigue and periods of rest. During a fatigue period (say, 3 weeks),you slowly build up fatigue, and never fully recover. Then you have a period of recovery (another 1-3 weeks) where you train with reduced frequency, volume, or intensity. (My preference is to keep intensity high, while drastically lowering volume and slightly lowering frequency.) At any rate, the fatiguing and recovery periods most likely won't be as drastic for a bodybuilder as it would for a strength athlete because there will be no peaking phase for performance (at no point are you required as a bodybuilder to perform a competition based on strength). Additionally, bodybuilder's need less fatigue and more recovery present at any given time (outside of the actual training sessions) when compared to strength athletes.

So here's what I've come up with

The general layout of the program will be to train upper body twice per week and lower body twice per week (so, we'll be providing double the training stimulus of typical one body part per day programs). The workouts will be fairly intense, heavy on free weight compound exercises, lower volume (per workout, and drastically lower volume per body part),and higher frequency than normal bodybuilding workouts. (Now, again, this is individual). Some of you won't be able to handle this amount of frequency yet, because your fitness level sucks. Some power lifters, OLY lifters, and other strength athletes train up to 20 or 30 times each week (and most of them a minimum of 10 times per week) because their fitness level is so high. If you find this level of frequency is too high, shorten the loading period and lengthen the recovery period, at first. Or, reduce the frequency to training three times per week, on a Mon, Wed, Fri, scheme, etc. until your preparedness is increased, and your body can handle the frequency.)

The real difference is in failure and periodization (this is so each body part can be trained twice per week as opposed to only once)

- No exercise should be taken to failure when using sub maximal reps, however, all exercises should be taken to within one or two reps of failure by the final set of the exercise. If muscular failure is reached, there is no way you can train with an increased frequency without overtraining.

- Periodization will be individual to the lifter. However, for the sake of this program a 3-week period of loading followed by one week of recovery is given. (Additionally, if one isn't fully recovered after the one week recovery period, and fatigue still builds, increase the recovery period to two weeks, or have a "recovery month" every 4 or 5 months where you'll have one week of loading and three weeks of recovery during that month to allow your body to fully recover.)

- Progressive Overload is absolutely imperative in every exercise, making sure that load or reps are increased, or that rest periods are decreased to keep intensity high (during loading phases). (Of course, during the recovery phases, if volume is lowered, and frequency reduced slightly, then intensity can and should still be kept high, although the load should be reduced just slightly (approx. 10%) as there is no reason to attempt to set records through progressive overload during this time of recovery.)

- Many different rep ranges will be used. I am partial to the use of rep ranges in the 3-10 range, as it tends to give the lifter a great balance of extreme muscle thickness (like the look of a bodybuilder with a power lifting background) as well as great neural efficiency.

A. Use of Neural Efficiency (as well as some Myofibril Hypertrophy) occurs in rep ranges of 1-3. (Neural Efficiency increases the percentage of motor units that can be activated at any given time. There is little to no effect on size but increases strength will be great. Little to no protein turnover occurs in this rep range as load is too high and mechanical work is too low.)

B. Mostly Myofibril and Sarcomere Hypertrophy and very little Sarcoplasmic Hypertrophy occur with rep ranges of 3-5. (Sarcomere hypertrophy increases contractile proteins in muscle thereby increasing strength directly and also size. Book knowledge suggests that growth here will be mostly myofibril/ sarcomere hypertrophy and will be accompanied with strength gains in other rep ranges and improvements in neural efficiency. Therefore this is perhaps the best rep range for increasing strength. Better balance of load / work done for hypertrophies so no surprises there.)

C. Myofibril, Sarcomere, and Sarcoplasmic Hypertrophy (lots of growth as well strength gain within this rep range with little transfer to 1rm) occur with rep ranges of 5-10. (Sarcoplasmic Hypertrophy does not directly increase strength but can affect it by increasing tendon angle at the attachment - but of course it increases size.)

D. Some Sarcoplasmic with little Myofibril and Sarcomere Hypertrophy occur in rep ranges of 10-15. (More fatigue and a greater extent of waste products are associated with this rep range. Possibly increase in capillary density.)

E. Capillary density increases with little Sarcoplasmic growth with rep ranges above 15. (Muscle endurance begins to become a factor (but who needs that?). Also, waste products are intense lactic acid buildup to the point of making some individuals sick.)


Sep 22, 2010
If you can find a way to have 5x5, and 3x3 not working enough and you need more. This works well. I believe it was Madcow who wrote this.