Undulating Periodization: The science behind our small group training
Alec explaining the workout for Barbell Strength | photo by Pao Sanchez
By Alec Bulat, Executive Trainer & Co-Owner — NW Fitness Project (Seattle, WA)
Before we dive in, let’s take a step back and talk about periodization. What is it, really?
At its core, periodization is a planned and organized approach to training that prepares an athlete—or honestly, any human who lifts weights—with the goal of producing specific adaptations at specific times. Training is broken down into long-term (macrocycle), medium-term (mesocycle), and short-term (microcycle) phases, each with clearly defined characteristics.
The whole point is simple: manage fatigue, drive adaptation, and ideally peak performance at the right time.
(Brown, 2024; Api & Arruda, 2022; Evans, 2019)
Alec spotting barbell chest press during Barbell Strength | photo by Pao Sanchez
I was fully prepared to take this blog post down the deepest rabbit hole possible—different periodization models, their theoretical foundations, how to apply them perfectly, and what the literature says about each one. Anyone who knows me knows that would be very on brand (hello, fitness nerd). But instead, let’s keep this practical.
We’re going to focus on three major types of periodization:
First, traditional (or linear) periodization. This model starts with high training volume and relatively low intensity, then gradually progresses toward lower volume and higher intensity over the course of several months. It’s predictable, structured, and has been used successfully for decades (Issurin, 2008; Evans, 2019).
Second, block periodization. This approach organizes training into highly focused blocks, each designed to develop a specific quality before moving on to the next. Most commonly, this includes an accumulation block (high volume, low intensity), a transmutation block (moderate volume and intensity), and a realization block (low volume, high intensity) that precedes competition. The idea is to concentrate stress, drive very specific adaptations, and peak at key moments (Issurin, 2008; Evans, 2019). You can read more about our views on block periodization here.
Lastly—and the main character of this article—we have undulating periodization. Undulating periodization alternates training emphasis between qualities like strength, hypertrophy, and muscular endurance. This can be done daily (daily undulating periodization), where volume and intensity change session to session, or weekly, where each week emphasizes a different focus. At NWFP, we typically use a weekly undulating approach—one week focused on hypertrophy, one on strength, and one on endurance.
Now, here’s the part that usually surprises people.
For the most part, the research says the same thing over and over again: undulating periodization is just as effective as linear and block-style training for improving strength and muscle outcomes (Api & Arruda, 2022; Brown, 2024; Harries et al., 2015).
I’d love to sit here and tell you that undulating periodization is the single most effective training methodology in the world. But like most training variables, effectiveness depends heavily on dosage, intensity, and consistency. No periodization model magically works if the fundamentals aren’t there.
That said, undulating periodization has demonstrated some unique benefits. Research has shown it to be effective for increasing fat-free mass in people who menstruate, particularly when training stress is aligned with physiological fluctuations across the cycle (Vargas-Molina et al., 2022).
So why do we use undulating periodization here at NWFP?
Two main reasons: accessibility and novelty.
Alec demoing bench chest press for Barbell Strength | photo by Pao Sanchez
While undulating and block periodization appear similarly effective from a results standpoint, undulating models tend to be far more forgiving for non-competitive lifters. The consistent rotation of training focuses makes it easier to stay engaged and consistent. You get repeated exposure to each stimulus without needing to perfectly execute a rigid, multi-month block structure. Miss a week? Not ideal, but you’re far less likely to derail the entire training plan.
The second reason is novelty—and this one matters more than people think. Alternating between hypertrophy, strength, and endurance exposes the body to varied training stimuli. You get the neural and force-production benefits of heavy strength work, the structural and muscular growth associated with hypertrophy training, and the local muscular endurance adaptations that improve work capacity.
Alec coaching warm up for Barbell Strength | photo by Pao Sanchez
More muscle means greater cross-sectional area, which increases strength potential. Improved neural efficiency means you can actually use that muscle. Better endurance means you can handle more work over time. Undulating periodization allows all of these qualities to be trained repeatedly, without burning any single system into the ground.
At the end of the day, periodization is just a tool. The best model is the one that you can execute consistently, recover from appropriately, and progress within over time. For most people doing our small group training classes at NWFP, undulating periodization checks all of those boxes. See you in class!
References:
Api, G., & Arruda, D. (2022). Comparison of periodization models: A critical review with practical applications. Journal of Applied Sports Sciences, 6(2), 77–105. https://doi.org/10.37393/jass.2022.02.7
Brown, Dylan R., (2024). "Effects of an 8-Week Undulating Training Program on Firefighter Body Composition, Muscular Fitness, and Occupational Performance". Electronic Theses and Dissertations. 2782. https://digitalcommons.georgiasouthern.edu/etd/2782
Harries, S. K., Lubans, D. R., & Callister, R. (2015). Systematic Review and meta-analysis of linear and undulating periodized resistance training programs on muscular strength. Journal of Strength and Conditioning Research, 29(4), 1113–1125. https://doi.org/10.1519/jsc.0000000000000712
Issurin, V. (2008). Block periodization versus traditional training theory: a review. The Journal of Sports Medicine and Physical Fitness, 48(1), 65–75.
Rhea, M. R., Ball, S. D., Phillips, W. T., & Burkett, L. N. (2002). A comparison of linear and daily undulating periodized programs with equated volume and intensity for strength. The Journal of Strength and Conditioning Research, 16(2), 250. https://doi.org/10.1519/1533-4287(2002)016<0250:acolad>2.0.co;2
Vargas-Molina, S., Petro, J. L., Romance, R., Bonilla, D. A., Schoenfeld, B. J., Kreider, R. B., & Benítez-Porres, J. (2022). Menstrual cycle-based undulating periodized program effects on body composition and strength in trained women: A pilot study. Science & Sports, 37(8), 753–761. https://doi.org/10.1016/j.scispo.2021.11.003
