by Michael C. Zourdos, Ph.D., CSCS
- A flexible template can allow you to “flex” in lighter training days to avoid poor performance on a heavy day when readiness to train is low.
- Although the concept of a flexible template is simple, there are various ways and degrees of flexibility in which this can be implemented.
- Finding the right way to assess readiness, and thus make decisions regarding what session-type to perform on a given day, is still new to the literature and may be individualized.
There’s always a day or two during a training cycle (or even every week) when we just don’t feel great; however, the work still needs to get done. Often, we decide to force ourselves to try to perform the prescribed work, which just ends in frustration from missed reps. For example, 5X5 @80% following only 4 hours of sleep might not be that easy. Similarly, 5X5 @80% at 5 a.m. or after a 12-hour workday is quite difficult. The coach in all of us knows performing a difficult session under any of these circumstances is a bad idea, but the athlete in us can’t resist. So, we take a bunch of caffeine and do the session anyways, though we might miss reps or have to significantly lighten the load. After the session, we spend the next 48 hours thinking about how terrible everything is and obsessing over how weak we have instantly become.
Well, there is a pretty easy way to avoid this issue, which is by using a flexible training template. In short, a flexible training template is having all of your weekly or monthly sessions laid out and then choosing which one you are going to do based upon your energy levels or daily “readiness” prior to the training session, rather than having to perform those sessions in a fixed order.
The premise behind the theory is this: If you try to perform a session when you are not ready, you might miss reps or have to decrease load, which will compromise volume and intensity performed, in turn decreasing the rate of long-term hypertrophy and strength adaptions. Indeed, data has shown a flexible template to be more effective than a fixed weekly training order for strength (1) and adherence to training (2). However, there are two main methodological differences between the two studies that exist on this topic. So even though using flexibility in training can be effective, there are questions that remain about the best way to implement this form of autoregulation. With that in mind, let’s briefly break down these two studies and then point out the two methodological differences to determine a way forward.
Study 1: McNamara and Stearne (2010):
McNamara and Stearne (1) had two groups of students in a college weight training class train two times per week for 12 weeks (24 total sessions). Both groups had sessions of 20, 15, and 10 reps, but one group performed those days in a fixed order (Tuesday – 20 reps, Thursday – 15 reps, Tuesday – 10 reps, and then repeat), while the other group could choose the order in which they did the sessions, with the stipulation that they had to do each session a total of eight times. This study found that the flexible template increased leg press strength to a greater extent than the fixed template. To determine what session-type the subjects in the flexible group did each day, they simply completed a 0-10 Likert scale regarding their daily energy levels and then chose their preferred session based upon their self-reported energy.
Study 2: Colquhoun et al. (2017)
Colqhuhoun et al. (2) utilized a flexible template versus a fixed template in powerlifters. The main training program here was eight weeks, and both groups had to perform one hypertrophy, one strength, and one power session within each week. The fixed group performed sessions in the order of hypertrophy (Monday), power (Wednesday), and strength (Friday), while the flexible group could choose the session order, but had to perform each one within a week. The authors noted that there was no difference between groups in squat, bench press, or deadlift volume or in maximal strength after the study. However, adherence to training was greater in the flexible group. The lifters in this study completed a 0-5 Likert scale assessing motivation to train and used that to decide what daily session to complete.
Aside from the population difference (weight training class versus powerlifters), there are two main methodological differences that set the stage for the rest of this article: differences in the amount of flexibility allowed and differences in the assessments of readiness. McNamara and Stearne allowed the subjects the freedom to choose any session-type they wanted as along as a pre-determined number of all session types was completed within 12 weeks. On the other hand, Colquhoun’s study allowed flexibility within a week, but all session types had to be completed within a single week; thus, Colquhoun allowed less flexibility than McNamara and Stearne. The second difference relevant to us is the different readiness assessments. One study used a 0-10 scale assessing energy, and the other used a 5-point scale measuring motivation to train.
So, what’s better? Restricting flexibility within a week similar to Colquhoun? Or allowing flexibility throughout an entire mesocycle like McNamara and Stearne?
What about readiness assessments? Are either of these Likert scales the way to go? Or are there other assessments that may give us a better gauge of readiness to allow us to make better decisions regarding our daily session?
Let’s investigate those two questions: 1) how much flexibility should be allowed? and 2) what assessments can be used to determine daily readiness and therefore determine what training session (heavy, medium, or light) should be performed?
How Much Flexibility Should be Allowed?
A daily undulating program stipulates various repetitions (3) or phases (4) be altered across 2-3 training sessions per week; thus, in a programming strategy that has different repetitions across a week, there will inevitably be some sequence of heavier and lighter sessions. Therefore, in a general sense, a flexible template allows the lifter to choose the lighter session when they aren’t feeling great and the heavier session when they feel better.
With the basic conditions from the paragraph above, let’s first give the most basic example of a flexible training template. If an individual trains an exercise or muscle group three times per week with one hypertrophy-, one power-, and one strength-type session, then the basic rules of a flexible template stipulate that each session-type is completed within a week, but the order in which they are done does not matter. Therefore, the lifter can assess their readiness and choose a session based upon that. Most likely, the power day will be performed when energy and recovery levels are low, the hypertrophy day when energy/recovery is moderate, and strength when energy/recovery is the highest (Table 1). One of the big questions is also, “how to determine your energy/recovery levels?” For now, let’s use the perceived recovery status (PRS) scale, which assesses both energy and recovery on a 0-10 scale (5). However, in the second part of this article, we’ll discuss the efficacy and utility of the PRS in greater depth.
Also, note in the scale below in Table 1 that I have suggested an off-day when a score of zero is recorded. In the case of a zero score, it is likely that training would be of such low quality that it’s not beneficial, or that recovery is so low that you might be risking injury. Simply take the day off and push training back a day. Of course, if you score a “0” on the PRS scale, you should also consider that you might be doing too much volume in one session to cause so much fatigue, but that’s a topic for another day.
Table 1: Basic Flexible Template Using PRS
|PRS Score||Choice of Session-Type|
Note: This table corresponds a PRS (perceived recovery status) score to the session-type that should be performed.
Before we expand upon the within-week flexibility presented above, let’s understand that everything is conceptual. This means varying degrees of flexibility can be implemented, so let’s explain each.
Table 1 shows within-week flexibility in that all three sessions (or two with a two-day per week frequency) must be completed within the week, but the order doesn’t matter. The theory is that by performing when you are ready, you will be able to complete more volume or train at a higher intensity than forcing yourself to perform a pre-determined training session that you might not be able to complete based on low readiness.
A within-week model is beneficial because it makes sure that the lifter trains through all of the repetition zones or intensities that are programmed. However, a drawback of the within-week stipulation is that if a lifter has an entire week in which energy levels or low (<4 on the PRS scale), then the lifter is forced to perform heavy work in a less-than-ideal state of readiness.
Within-Training Block Flexibility
This strategy rectifies the limitation of the within-week in that it allows for three easy days to be performed within a week if readiness is low each day. So, rather than stipulating that all session-types need to be performed within a week, this approach mandates that a certain number of each session-type must be performed over the course of the entire training block. For the sake of argument, let’s say a training block lasts two months and you want to train 30 times within that time span (about every other day). Further, it’s a volume block and you are training three days per week, so your reps across the week for each exercise are 10 reps (Day 1), 8 reps (Day 2), and 6 reps (Day 3). With 30 total sessions and three different repetition schemes, you determine you want to complete 10 sessions of each type over the two months, but the order doesn’t matter. Rather you’ll use the PRS scale – the lower the PRS, the higher the reps – meaning the less energy/recovery, the lower intensity day that you will choose. This approach allows for more variation than the within-week approach, so if low PRS scores occur on successive days, you have more freedom to choose a lighter session. Of course, this can be implemented with the power days as mentioned above (I am just trying to present different examples of undulating models). Everything is conceptual and everything can be integrated, so of course you could perform 10 hypertrophy-, 10 power-, and 10-strength-type days in this example, rather than just cycling through 10, 8, and 6 repetitions. And of course you could also cycle through an even higher or lower repetitions scheme.
The definition of an “unlimited” flexible strategy is self-explanatory: you simply could perform heavy, medium, or light days depending on your readiness with no stipulations on how frequently session types might be performed. While, conceptually, this makes sense based upon the previous results, I think the obvious drawback – “too much flexibility” – outweighs the benefits. In reality, a flexible model with no stipulations could cause you to always gravitate toward your training preference, which could cause too much strength work and not enough volume work or vice versa, depending on your goals. It’s also possible no stipulations could cause someone to always perform light work; however, I think the opposite is more likely.
In this strategy, a lifter would have a predetermined training order, but could “flex” in a light day when readiness is low. This is where I like to a keep a power day (i.e. 3X1 @80%) in my back pocket. Whether you are altering phases each session with hypertrophy, strength, and power as described above, or simply altering repetitions throughout a week (i.e. 10, 8, 6 on Monday, Wednesday, and Friday), you can insert an easy-to-complete power session when needed. Table 2 seen below demonstrates inserting a power day when needed and then continuing on with the pre-determined order of training.
Table 2: Example of a “Somewhat” Flexible Template
|Week||WEEK 1||WEEK 2|
|Fixed “Phases” Setup||H||P||S||H||P||S|
|Somewhat Flexible “Phases” Template||H||P||P*||S||H||P|
|Fixed “Reps” Setup||10||8||6||10||8||6|
|Somewhat Flexible “Reps” Template||10||8||P*||6||10||P*|
*Represents a power-type session is flexed in due to low readiness, then training simply continues on with the scheduled training in the next session. H= Hypertrophy-Type Session, P= Power-Type Session, and S= Strength-Type Session.
A general rule for performing a power-type session in the somewhat-flexible model is that if your PRS is <4, use the power session; if it’s greater than or equal to 4, then continue on as planned. In reality, the power day is just a light day, so any light day could really be performed. This strategy also begs the question: why not just take the day off instead of flexing in the light day? Well, if PRS is 0, then I would absolutely take the day off, but training with a PRS of 1-4 allows you to keep your normal frequency, which allows for more skill practice. Additionally, training with the light day may also improve muscle recovery via increased blood flow, and there is evidence that a light training session may enhance performance 48 hours later (5), which is typically when the next session falls. Finally, I favor training in lieu of rest in this case for the mental benefit. Taking the day off when you are already scheduled to train may have you itching for the next session or may leave you feeling guilty, while performing a light session still allows you the satisfaction of training.
Theoretically, you could use the somewhat-flexible model all the time, and that is actually what I do. We all have unexpected stressors in life that take priority over training; however, a lot flexibility is not always a good thing. The somewhat-flexible model avoids the free-for-all of unlimited flexibility by having a structured order, allowing for a light day in the case of little sleep, a very early morning session, etc.
Lastly, flexible strategies are not relegated to readiness; they could also be used for time efficiency. For example, let’s say you are set to perform 5 sets of 4 @80-85% of one-repetition maximum (1RM) on the squat on Friday. On Thursday night, you learn of something unexpected that will have you tied up after work on Friday, and now the only time you have to train is from 5:15-6 a.m. on Friday morning or on your lunch break. In this case, flexing in a power day and delaying the heavy session 48 hours might be a good idea.
Final Word on Choosing a Flexibility Strategy
All strategies above can be effective; however, keep in mind that unlimited flexibility may not allow for appropriate distribution of session-type. Ultimately, using a flexible template – in which you use a power or light day when readiness is low – can certainly increase adherence to training and can avoid the “disaster” session in which you have low readiness and perform terribly on a high-volume or high-intensity day.
What Assessments Can Be Used to Determine Daily Readiness?
Although most people are likely to place more emphasis on the first question answered in this article, I firmly believe that this question in regards to method of daily readiness is just as important.
Using a flexible template is one form of autoregulation (adjusting or progressing load and volume are other forms). Importantly, autoregulation is a strategy of making the aforementioned changes within a periodized program. This means that autoregulation in and of itself is not a training structure; rather, it is a strategy to manipulate certain variables that can take different forms. Overall, this boils down to the principle that autoregulation is about making decisions from data that you collect. Thus, it is important to collect the right data and then make the right decision that translates into positive outcomes. If we collect that wrong data, then that decreases the likelihood of us coming to the right decision. In short, the tool we use to assess readiness matters.
It would be impossible to examine all the ways to assess daily readiness, so I will keep the analysis to what has been used in applicable studies and what is easy and practical for the lifter to track. For example, daily testosterone to cortisol ratio may be able to assess daily readiness and predict performance outcomes; however, this is impractical for a lifter to assess each day, and thus does not warrant discussion here. These assessments can be broken down into two subcategories: A) assessments prior to the commencement of training, and B) assessments during the warm-up.
Assessments Prior to Training
Assessments prior to training include the Likert scales and PRS scale already discussed, along with anxiety (and other factors), which can be assessed via psychological well-being scales. A main drawback of the Likert scales, which measure energy and motivation to train, is that even though the scale itself is objective, the rating is subjective. I realize that the objective/subjective paradigm could be said about many things, but in this case, the scales are not really asking specific questions, thus the answer may not always match reality. However, to counter that argument, someone can certainly give an energy level with relative accuracy. So the real question is: Does that energy level actually predict performance? If this doesn’t predict performance, then these scales are not autoregulatory tools that we can make decisions based upon.
The PRS scale has become widely used recently since its inception in 2011 by Laurent et al. (6). There is evidence in the literature that PRS is related to performance, as it was shown to be inversely correlated (r= -0.63) with sprint performance, in that a higher PRS (more well-recovered) was related to better sprint times. However, our lab showed that during a cycle of daily 1RM squatting, the PRS was largely unreliable at predicting the daily 1RM (7). Also, the PRS failed to be related to 1RM or repetition squat performance in a recent thesis from our laboratory (unpublished at this moment). Similar to the Likert scales, I think lifters can gauge their level of recovery fairly accurately; however, the PRS does not seem to consistently predict performance, thus this calls its usefulness as an autoregulatory tool into question. Just think about your training history for a moment: Has there ever been a time when you felt terrible and had a great training session? And has there ever been a time when you felt great and had a terrible training session? I’m sure these have both occurred, so it’s possible that we may want to consider other assessment tools.
Other assessments that can be used prior to training include various sports psychology well-being scales. Among these types of scales, the measure of anxiety is common. Within anxiety, we can distinguish between somatic and cognitive anxiety, with somatic being the physical symptoms of anxiety and cognitive being the mental consequences. The competitive state anxiety inventory-2 (CSAI-2) (8) assesses somatic anxiety with items such as: “I feel jittery” and cognitive with questions such as: “I am concerned about losing.” There are various studies showing the effects of chronic resistance training on anxiety, but less data regarding the relationship between anxiety and acute performance. There is, however, data demonstrating an inverse relationship between cognitive anxiety and performance (9) and a direct relationship between cognitive anxiety and performance (10) in various sports. Additionally, the recent thesis from our lab, which was mentioned above, has also shown a positive relationship between cognitive anxiety and acute maximal squat strength in both trained men and women. While, the recent data is interesting, it is only one study, and a meta-analysis suggests equivocal findings for an anxiety and performance relationship (8). What this means is that high anxiety may be facilitative for some lifters and debilitative for others, so there is likely not a one-size-fits-all approach here. Rather, the individual would have to figure out if high or low anxiety is good for them.
Assessments During the Warm-Up
One of the problems identified in the above subsection is that while an individual can certainly gauge their energy or recovery, we don’t know if these factors predict performance. So, with these limitations, why not just use performance to assess readiness? You can score yourself on the PRS scale and have an idea of what you think you’re capable of for the day, but start warming up and then during your warm-up sets record rating of perceived exertion (RPE) values and average velocity (if you have access to that). Then, use these values to choose your daily sessions.
To illustrate this concept, let’s think back to our hypertrophy, strength, and power-type sessions similar to Colquhoun’s study (2). Let’s say we are using within-week flexibility for this. The intensity on the hypertrophy day is 75%, the power day is 80%, and the strength day is 85% of 1RM. So, in all cases, 70% of 1RM is below the working weight for the day. Therefore, use 70% as your last warm-up and record RPE and a velocity value. Then, you can use these values to determine your daily session. Essentially, the higher the RPE (lower the repetitions in reserve – RIR), the easier session you choose. For average velocity, there would be a direct relationship; the higher the velocity, the harder the session you would choose. When comparing RPE and velocity in the literature, data have actually demonstrated that RPE on the last warm-up set was more consistently related to daily 1RM squat performance than average velocity on the last warm-up set (7). It is worth noting that that RPE was taken at 85% of 1RM, and RPEs are more accurate when closer to failure (11, 12); thus, this might not be as reliable at 70%. However, even if you can’t predict exact RIR with precision after one rep at 70%, you can still get a sense of how heavy it feels, which may be enough to realistically assess readiness and choose the day’s session-type.
Final Word on Assessments
There are a lot of ways to assess daily readiness, and this article simply scratches the surface. However, it may be advisable to begin warming up and make your choice of session-type within the flexible template based upon how warm-up sets feel rather than a pre-training scale or questionnaire.
Summary, Further Thoughts, and Takeaways
In summary, using a flexible template is a viable autoregulation strategy and can be implemented with varying degrees of flexibility. Remember, data exist not only showing that a flexible template can enhance strength, but that it may also increase adherence. In reality, adherence is one of the most important factors to consider in any program design methodology; if you or your client doesn’t adhere to the program, then nothing else matters.
Further, don’t underestimate the importance of finding out what strategy works best for you to assess readiness. Since the literature is currently equivocal, you may need some trial and error with readiness assessments; however, don’t neglect taking readiness assessments during the warm-up, as this method is often overlooked.
When using this article to help your training, remember that nothing is magic. Using flexibility in training is just one tool of many that can help long-term progress. So, as always, remember to understand the concept. In this case, the concept is: Using flexibility can help you perform when you’re ready and avoid the terrible training session that will inevitably occur as a result of poor daily readiness.
- McNamara JM, Stearne DJ. Flexible nonlinear periodization in a beginner college weight training class. The Journal of strength & conditioning research. 2010 Aug 1;24(8):2012-7.
- Colquhoun RJ, Gai CM, Walters J, Brannon AR, Kilpatrick MW, D’agostino DP, Campbell WI. Comparison of powerlifting performance in trained men using traditional and flexible daily undulating periodization. The Journal of Strength & Conditioning Research. 2017 Feb 1;31(2):283-91.
- Klemp A, Dolan C, Quiles JM, Blanco R, Zoeller RF, Graves BS, Zourdos MC. Volume-equated high-and low-repetition daily undulating programming strategies produce similar hypertrophy and strength adaptations. Applied Physiology, Nutrition, and Metabolism. 2016 Feb 16;41(7):699-705.
- Zourdos MC, Jo E, Khamoui AV, Lee SR, Park BS, Ormsbee MJ, Panton LB, Contreras RJ, Kim JS. Modified daily undulating periodization model produces greater performance than a traditional configuration in powerlifters. The Journal of Strength & Conditioning Research. 2016 Mar 1;30(3):784-91.
- Tsoukos A, Veligekas P, Brown LE, Terzis G, Bogdanis GC. Delayed effects of a low volume, power-type resistance exercise session on explosive performance. The Journal of Strength & Conditioning Research. 2017 May 25.
- Laurent CM, Green JM, Bishop PA, Sjökvist J, Schumacker RE, Richardson MT, Curtner-Smith M. A practical approach to monitoring recovery: development of a perceived recovery status scale. The Journal of Strength & Conditioning Research. 2011 Mar 1;25(3):620-8.
- Zourdos MC, Dolan C, Quiles JM, Klemp A, Jo E, Loenneke JP, Blanco R, Whitehurst M. Efficacy of daily one-repetition maximum training in well-trained powerlifters and weightlifters: a case series. Nutrición Hospitalaria. 2016;33(2).
- Craft LL, Magyar TM, Becker BJ, Feltz DL. The relationship between the Competitive State Anxiety Inventory-2 and sport performance: A meta-analysis. Journal of sport and exercise psychology. 2003 Mar;25(1):44-65.
- León-Prados JA, Fuentes I, Calvo A. THE RELATIONSHIP BETWEEN ANXIETY STATE, SELF-CONFIDENCE AND PERFORMANCE IN BASKETBALL. Revista Internacional de Medicina y Ciencias de la Actividad Física y del Deporte. 2014 Sep 1;14(55).
- Kais K, Raudsepp L. Cognitive and somatic anxiety and self-confidence in athletic performance of beach volleyball. Perceptual and Motor Skills. 2004 Apr;98(2):439-49.
- Zourdos MC, Klemp A, Dolan C, Quiles JM, Schau KA, Jo E, Helms E, Esgro B, Duncan S, Merino SG, Blanco R. Novel resistance training–specific rating of perceived exertion scale measuring repetitions in reserve. The Journal of Strength & Conditioning Research. 2016 Jan 1;30(1):267-75.
- Hackett DA, Cobley SP, Davies TB, Michael SW, Halaki M. Accuracy in estimating repetitions to failure during resistance exercise. The Journal of Strength & Conditioning Research. 2017 Aug 1;31(8):2162-8.