Interview with Dr. Mike Zourdos on Daily Undulating Periodization (DUP)

Posted by Derek Charlebois on

Strength training periodization is programmed phasic variation in training volume, intensity, and/or frequency to maximize performance and training adaptation. There are multiple types of periodization models; one being daily undulating periodization (DUP), which I currently utilize with great success with my clients and myself. To give insight into the DUP system of training I thought whom better to talk to than Dr. Mike Zourdos a leading researcher in periodization and competitive powerlifter.

Dr. Mike Zourdos Bio: Mike is an Assistant Professor in Exercise Science at Florida Atlantic University (Boca Raton, FL.) with a specialization in strength and conditioning and skeletal muscle physiology and adaptations.  He earned his Ph.D. in Exercise Physiology from The Florida State University (FSU) in 2012.  Prior to attending FSU Mike received his B.S. degree in Exercise Science from Marietta College and M.S. in Applied Health Physiology from Salisbury University. At Marietta Mike lettered in soccer for four seasons and captained the squad in his final two. While at Salisbury he also served as the graduate assistant strength and conditioning coach for all sports teams.  Further, Mike served as the Head Powerlifting Coach of FSU’s 2011 and 2012 state championship teams and currently serves as FAU’s Head Coach in addition to being a faculty member.  Mike’s research focus on optimizing periodization and program design methods, such as his dissertation entitled: “Physiological Responses to Two Different Models of Daily Undulating Periodization in Trained Powerlifters.”  This line of high performance research is currently ongoing in the FAU “Muscle Lab.” His best competition lifts include a 227.5kg (501lbs.) squat as an 83kg lifter at the 2013 Arnold Sports Festival Raw Challenge and again at the 2013 USAPL Florida State Championships.  Finally, Mike is recently married to Dr. Catherine Coccia, Ph.D., R.D., and Assistant Professor in the department of Nutrition and Dietetics at Florida International University.


Derek: Hey Mike. I appreciate you taking the time to do this interview. Over the past year or so daily undulating periodization (DUP) has gained tremendous popularity due primarily to you and your work (research, client results, etc.). I feel like there is some confusion though as to what DUP actually is. Some people think DUP is one specific weight training routine when it is really a system of training. Can you give us a basic overview of the DUP system? 


Mike: I am happy to take part Derek, thank you for the opportunity.

This is an excellent question to start us off.  The abbreviation DUP stands for ‘Daily Undulating Periodization.’  First, it is necessary for athletes to understand that DUP is not a training routine; rather it is a theory, concept, or system of training.  That is to say that it is not a specific routine that can be downloaded from the internet, in which someone can simply plug in their numbers and run the program.

Rather, DUP is a theory based upon the last 25 years of scientific research, where training variables (volume, intensity, and frequency) are manipulated throughout a training cycle in an attempt to optimize muscle performance gains.  More specifically undulating periodization designates changing either between hypertrophy, strength, and power-type training every single session or even more simply changing between high, moderate, and low repetition training every session.  In contrast, the older-style linear periodization model would stipulate changes in training variables less frequently (i.e. 3-4 weeks).

Therefore, understand that DUP is not a set frequency of training.  The concept can be fit around your schedule.  For example, if someone is training 6 days/wk. with 3 days lower- and 3 days upper-body training, but their schedule changes and now they can only train 2 or 3 days /wk. it does not mean that they cease utilizing the concept of DUP.  Rather, since it is a concept, the undulation pattern would just change to fit those 2 days.  This is one reason why it is important to understand the reasoning behind training theory, so that adaptations can be made and training can still be scientifically sound.  Because of this all types of athletes utilize DUP, not just strength athletes.


Derek: That is a very good overview Mike. I know this is a loaded question, but could you explain why it is more beneficial to change the type of training session performed every training session vs. the traditional linear periodization model?


Mike: Sure.  There are multiple drawbacks to the linear model as opposed to the more frequent variation implemented with DUP. (1) Loss of training adaptation due to time spent in one phase (2) Lack of practice at recruiting high-threshold motor units (leading to decreased efficiency) and (3) Understanding that strength is a significant contributor to hypertrophy.  Let’s look at each one.

  1. In the linear model a lifter may go 4-6 weeks and only perform either hypertrophy or strength training. With this style the lifter may lose adaptation of the phase, which he/she is not focusing on.
  1. The second one to me is the most important and really comes down to the concept of specificity. This is the practice and efficiency to recruit high-threshold motor units.  A motor unit is a motor neuron (from the nervous system – skeletal muscle is innervated by the somatic nervous system) and all of the fibers that the neuron innervates.  The motor neuron will innervate either type I or type II fibers.  In normal training type I fibers are recruited first and then type II fibers as needed – this is referred to as the size principle.  However, by training the neuromuscular connection a lifter can become more efficient at recruiting type II fibers to move heavier weight and enhance rate of force development.  And the heavier one trains the more practice a lifter gets at practicing efficiency of high-threshold motor unit recruitment.  In short, as this efficiency increases strength and skill with heavier weights will increase.  Ultimately, when strength increases a lifter can overload more and perform more volume.  In a DUP model a lifter gets to perform ‘strength days’ at least once per week to practice this process.  This brings us to #3.
  1. The most important factor for muscle hypertrophy and strength is training total volume (TV) with intensity being next. TV can be calculated: Sets X Repetitions X Wt. Lifted.  Thus, as a lifter increases strength as outlined in #2 the component of TV ‘Wt. Lifted’ will increase, therefore TV will increase leading to more growth and more strength.  It is necessary to note here that TV takes precedence over training induced muscle damage as the primary factor behind skeletal muscle hypertrophy.  Therefore, it is most advantageous to setup a DUP model that aims to optimize volume over time rather than one that calls for excessive volume in one session, which leads to significant amounts of damage.  As a result of excessive damage a lifter may not be able to train effectively again for quite a while, which leads to less frequency and less volume in the long run.

This is essentially, illustrating that hypertrophy, strength, and power, are all interrelated.  However, the conversation is even much bigger than the answer to this question.  In a DUP model the concept of linear periodization never goes away.  In fact, DUP is the overwhelming concept, but a very important concept to note is that DUP, linear periodization, principles of autoregulation, and block periodization are not mutually exclusive.  The sentence below sums this up:

If DUP is setup in a block periodization fashion (i.e. volume or intensity) and progression each week is based upon the previous week’s performance (an element of autoregulation) and volume is still decreased as a lifter draws nearer to competitions, all of these principles were utilized. 

This is where our research is currently expanding into.


Derek: So to summarize, a DUP protocol is structured to maximize neurological adaptations (both strength and skill in executing the movement) and muscle hypertrophy.  Using squats as an example, to correctly implement the DUP theory of training must one perform a hypertrophy squat workout, a strength squat workout, and power squat workout for a total of three squat workouts every week?


Mike: Great question.  That is one way to setup it up, and would be very effective, but there are really endless possibilities of how to setup a DUP model.  In other words, the total frequency of a lift per week and the frequency of each training emphasis (i.e. hypertrophy, strength, or power) do not have to be a 1:1:1 ratio.  This ratio can and should be manipulated depending on individual goals.  

Actually, someone said to me recently, “So your study found the optimal DUP design?”  I almost had a heart attack when I heard this.  I said, “No, my study simply showed that one design yielded superior volume and strength than another design in trained lifters.”  We have to understand that there are endless possibilities and we will never find the exact optimal protocol, and to me that is an amazing thing; because it always means more research, more teaching, more learning and more discussion.  

The literature shows an important concept, but all that means is that research needs to continue.  And remember, this concept has been around for many years and has been investigated by some great researchers over the past 25 years or so.

To continue on the concept of ‘training ratios’ we must understand the principle of specificity.  For example a powerlifter might train with a ratio of 2:1:1 in favor of strength, a bodybuilder 2:1:1 in favor of hypertrophy.  Maybe the ratio should be 3:1:1 or 4:2:1…what is the optimal ratio?  I am not even remotely smart enough to declare an exact ratio, but what we do know is the variation of training variables and the principle of specificity is important.

In reality frequency of the squat could be 3, 4, 5 times per week or even more.  This will vary depending on whether the lifter is in a volume or intensity block.  Most importantly, the frequency/volume will be dependent on what the lifter has previously adapted to.  The goal is more volume, but it is inappropriate to immediately go from 1X/wk. frequency to 4X/wk., rather volume should be progressed appropriately, and introductory microcycles and taper weeks should be introduced to facilitate this process.


Derek: The endless search for the optimal training protocol is one part of strength training that I really enjoy because as you said, there is always more to research and learn.

Can you expand on the difference in programming between volume and intensity blocks?


Mike: Absolutely.  In short, they are just as they sound.  A volume block will contain more volume and an intensity block more intensity.  But, now we are really getting into integrating DUP, block, and autoregulation all in one, and that is truly the direction we need to go into.

Volume: First, understand that a volume block is not looking to throw a ton of volume into one day, because that creates unnecessary damage, and as was said above volume is more important than damage.  Therefore, the goal is to encompass lots of volume throughout the course of a week, block, or year.  To do this we have to train submaximally, therefore most sets during a volume block should fall around an 8RPE.  In other words on a scale of 1-10, with 10 being max effort, 8RPE means you rack the bar when you could do 2 more reps. I understand to many people it sounds ridiculous to rack the bar when you can still do 2 more reps, but when you are squatting 3, 4, 5 days/wk. you want to avoid the extra damage in favor of more frequent training, which of course leads to more volume and more skill practice.

For example a volume block might call for 5 sets of 8 @70% on the squat on day 1 of the week.  Now, someone might be able to do 15 repetitions on one set of 70%, but that will create excess damage.  The former strategy will allow the athlete many chances to practice the skill, achieve a certain level of volume, and still allow this athlete to squat again 2-3 more times that week.

Additionally, a volume block usually encompasses higher repetition undulation patterns throughout a week, i.e. 10, 8, 6 or 8, 6, 4.  This is because it is easier to achieve greater TV through higher repetitions.  Of course, a volume block could utilized a 5, 3, 1 undulation pattern, it would just require a lot of sets to achieve a volume threshold.  Since, higher repetitions are usually utilized a volume block would be used farther away from a competition.

Intensity: Obviously an intensity block will work much closer to a 1RM, and the undulation pattern throughout a week is typically lower repetitions: i.e. 5, 3, 2.  But, with any block there are infinite ways to set this up, the best thing to do at this point is to give 2 examples so there is some practical information:

Example 1: Monday: 4X5 @80%, Wednesday: 5X3 @85%, Friday: 6X2+ @87.5%

Example 2: Monday: 3X5 @80%, 2X1 @85%, Wednesday: 4X3 @85%, 2X1 @90%, Friday: Max, 4X3 @85% of Daily Max

Okay, so again, these are simply 2 examples of which there are infinite possibilities.  Additionally, we only see one week of each example above, therefore it does not show progression.  Progression could happen in many different ways: 1. Adding an arbitrary amount of weight, autoregulating, or even using a tendo unit (essentially another form of autoregulation).

But, it is important to note here that this shows how each week and each block is set up in a DUP fashion, but still maintains the principles of block periodization and volume/intensity progression over time.  Of course frequency can be manipulated many different ways (and should progress over time as well).

Note, that in ‘example 1’ you see the following: ‘Friday: 6X2+ @87.5%’.  The plus stands for ‘plus set’.  In this model you would perform 5 sets of 2 and then as many as possible on the last set, but not quite until failure…essentially to about a 9.5RPE.  So, this model serves 2 purposes; 1. It offers a gauge of progression each week, 2. You can choose how much you increase in load each week based upon how many reps are hit on the plus set.  This is essentially a form of autoregulation or autoregulatory progressive resistance exercise (APRE).

Finally, to reiterate the overlapping principles of linear and DUP, it is important to state that if the volume block precedes the intensity block, it is likely that the intensity block will be more effective.  This is due to the increased cross-sectional area of skeletal muscle (i.e. hypertrophy) that will occur during the volume block, thus strength can now come to fruition during the intensity.  This stems from the principles of linear periodization that a hypertrophy mesocycle would normally precede a strength/power mesocycle.


Derek: Can you also expand on the role and importance of intro/taper weeks as these are not including in “standard” programs and a lot of people are not familiar with these?


Mike: Absolutely, these are both very important to understand and implement. 

An introductory microcycle, ‘intro cycle’, is one of the most overlooked parts of a program.  Let’s think logically for a minute…if you are unaccustomed to a specific exercise or a level of training volume, the first time you try it, you will experience fatigue and soreness in the days following due to load-induced myofiber damage.  However, the next time you train you will have less damage and soreness and the next time even less.  This phenomenon is referred to as the repeated bout effect (RBE).  Therefore, it is not a successful strategy to jump immediately into higher volume training without preparing, so volume should be progressed appropriately.  We can progress volume appropriately by implementing an introductory cycle with about 50% of the weekly volume that a training block will have.  Essentially the introductory cycle is designed to elicit the RBE and ‘protect’ against damage in the following weeks.

Often times an intro cycle looks easy on paper and someone will think they are working hard by skipping it and jumping straight into the full training block, but this is a recipe for disaster.  Admittedly, I am guilty of this myself from time to time.  But, we have to understand that it is often the hardest to adhere to discipline and a strong work ethic when we have to control ourselves from doing too much too soon.  And intro cycle is a necessary part of the process.  While that week may be easy, understand that everything serves its purpose and the intro cycle is allowing the lifter to make the initial adaptation the frequency/volume.

Tapering is an interesting concept.  And the fact that it is a concept and not a ‘one size fits all’ principle is very important.

The principles of a taper are as follows: 1. Decrease volume, 2. Maintain intensity, 3. Maintain frequency.  Therefore, it is a concept, because the taper is dependent upon the volume and intensity of training that the athlete is involved in.  Tapering from a volume block will result in utilizing lower intensity during the taper week than will tapering from an intensity block.  Even further, if someone is performing a 1RM 3X/wk. on a lift (or even everyday…), intensity must be maintained for the most part, but volume should decrease.


Derek: Thank you for the fantastic answers Mike as they give great insight into the interworking of the DUP training system.

So to summarize this interview, the DUP training system encompasses varying volume/intensity on a daily or training session basis to maintain training adaptations, practice and become efficient at recruiting high threshold motor units, and maximize total training volume to increase muscle hypertrophy and strength. There are endless possible ways to structure a DUP training block by varying volume, intensity, and frequency as well as training ratios of hypertrophy, strength, and power sessions. Perhaps the most important concept readers should take away from this interview is optimizing total training volume over time, not in a singular workout, maximizes muscle hypertrophy and strength gains; creating excessive damage in a singular workout can decrease the ability to train frequently and decrease the overall volume you can perform in the long run. 

I want to thank you Mike for taking the time to do this interview. There is already a ton of information to read and digest so perhaps we can continue this with a part two interview. 


Mike: Very happy to participate Derek and thank you for the opportunity, and I look forward to part 2.  It's great to be able to talk about training methodology/periodization, which often gets lost among so many gimmicks.  If any of your readers wish to contact me, I can be reached at:  I would also like to thank my graduate students Alex Klemp and Chad Dolan for assisting in these responses.  Additionally, I want to thank my good friends Ben Esgro, Dr. Layne Norton, Matt Gary, and Mike Tuchscherer and my research mentor Dr. Jeong-Su Kim who have each played a significant role in shaping my professional and training careers.


Stay tuned for part 2 of the interview and be on the lookout for Dr. Zourdos’ continued research on periodization.

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