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ObservationalPeriodization
Men grouped by relative squat strength completed eleven weeks of block periodization. Every group improved, but percent change favoured the weakest group by a large to very large margin while the strongest group produced the highest absolute loaded jump heights.
How Fibral applies it: Expect the same program to move a beginner far faster in percentage terms than an advanced lifter, and judge an advanced lifter's progress on smaller increments.
Limits and applicability
No limitation statement has been published for this note yet. Treat it as a general evidence-informed rule, not an individualized guarantee.
- Wetmore AB, Moquin PA, Carroll KM, Fry AC, Hornsby WG, Stone MH. (2020). The Effect of Training Status on Adaptations to 11 Weeks of Block Periodization Training. View source
Approved content v1 · updated Aug 17, 2026
Randomized trialPeriodization
Previously untrained participants had their legs randomized to progress overload either by adding load or by adding repetitions over ten weeks. Both routes produced the same increases in one-rep-max leg extension strength and vastus lateralis cross-sectional area.
How Fibral applies it: Progress by adding load or by adding repetitions, whichever the equipment and the lift allow; the choice does not change the outcome.
Limits and applicability
No limitation statement has been published for this note yet. Treat it as a general evidence-informed rule, not an individualized guarantee.
- Chaves TS, Scarpelli MC, Bergamasco JGA, Silva DGD, Medalha Junior RA, Dias NF, Bittencourt D, Carello Filho PC, Angleri V, Nóbrega SR, Roberts MD, Ugrinowitsch C, Libardi CA. (2024). Effects of Resistance Training Overload Progression Protocols on Strength and Muscle Mass. View source
Approved content v1 · updated Aug 17, 2026
Expert consensusPeriodization
A position stand on progression models recommends that when training at a specific repetition-maximum load, a 2 to 10% increase in load be applied once the lifter can perform the current workload for one to two repetitions beyond the target. It frames progressive overload as a triggered step rather than a fixed weekly increase.
How Fibral applies it: Raise the load by 2 to 10% once the lifter clears the rep target by one to two repetitions, rather than adding weight on a fixed schedule.
Limits and applicability
No limitation statement has been published for this note yet. Treat it as a general evidence-informed rule, not an individualized guarantee.
- American College of Sports Medicine. (2009). American College of Sports Medicine position stand. Progression models in resistance training for healthy adults. View source
Approved content v1 · updated Aug 17, 2026
Meta-analysisPeriodization
In volume-equated programs, undulating periodization produced greater one-rep-max gains than linear periodization, but a subgroup analysis showed this held only for trained individuals. Previously untrained lifters gained the same from either model, and hypertrophy did not differ.
How Fibral applies it: Undulate volume and intensity within the week once a lifter is trained and chasing maximal strength; for a beginner either model works, so choose the simpler one.
Limits and applicability
No limitation statement has been published for this note yet. Treat it as a general evidence-informed rule, not an individualized guarantee.
- Moesgaard L, Beck MM, Christiansen L, Aagaard P, Lundbye-Jensen J. (2022). Effects of Periodization on Strength and Muscle Hypertrophy in Volume-Equated Resistance Training Programs: A Systematic Review and Meta-analysis. View source
Approved content v1 · updated Aug 17, 2026
Randomized trialPeriodization
A systematic review of subjective and objective autoregulation methods found that every autoregulation protocol it reviewed increased one-rep-max strength, with effect sizes ranging from small to large. Subjective methods such as reps-in-reserve RPE and flexible undulating periodization and objective methods such as velocity targets were both effective.
How Fibral applies it: Build autoregulation into the plan rather than around it: adjust load or volume from the lifter's daily readiness inside a periodized structure.
Limits and applicability
No limitation statement has been published for this note yet. Treat it as a general evidence-informed rule, not an individualized guarantee.
- Larsen S, Kristiansen E, van den Tillaar R. (2021). Effects of subjective and objective autoregulation methods for intensity and volume on enhancing maximal strength during resistance-training interventions: a systematic review. View source
Approved content v1 · updated Aug 17, 2026
Randomized trialPeriodization
Amateur rugby players completed matched training blocks with intensity prescribed either from barbell velocity or from rating of perceived exertion. Both improved squat, bench press and countermovement jump, and the velocity-prescribed block produced the larger improvements.
How Fibral applies it: Where a velocity measurement is available, prescribe intensity from it; where it is not, a perceived-exertion prescription still works, just less well.
Limits and applicability
No limitation statement has been published for this note yet. Treat it as a general evidence-informed rule, not an individualized guarantee.
- Shattock K, Tee JC. (2022). Autoregulation in Resistance Training: A Comparison of Subjective Versus Objective Methods. View source
Approved content v1 · updated Aug 17, 2026
ObservationalPeriodization
Resistance-trained men followed a mixed-session periodized program for ten weeks either with or without a perceived-recovery scale adjusting daily volume. The autoregulated group accumulated more total volume but gained no more muscle thickness, strength or power.
How Fibral applies it: Use autoregulation to protect a good plan on bad days, not as a way to add volume; extra autoregulated volume did not buy extra adaptation.
Limits and applicability
No limitation statement has been published for this note yet. Treat it as a general evidence-informed rule, not an individualized guarantee.
- Bartolomei S, Francesco L, Latini D, Hoffman JR. (2024). Autoregulation Does Not Provide Additional Benefits to a Mixed Session Periodized Resistance Training Program in Trained Men. View source
Approved content v1 · updated Aug 17, 2026
Meta-analysisPeriodization
A meta-analysis comparing autoregulated load prescription with percentage-based prescription found no significant difference in one-rep-max strength. Within the same review, velocity-loss thresholds at or below 25% favoured strength while thresholds above 20 to 25% favoured hypertrophy.
How Fibral applies it: Prescribe load by percentage or by autoregulated effort as the lifter prefers, since strength outcomes match either way.
Limits and applicability
No limitation statement has been published for this note yet. Treat it as a general evidence-informed rule, not an individualized guarantee.
- Hickmott LM, Chilibeck PD, Shaw KA, Butcher SJ. (2022). The Effect of Load and Volume Autoregulation on Muscular Strength and Hypertrophy: A Systematic Review and Meta-Analysis. View source
Approved content v1 · updated Aug 17, 2026
Randomized trialPeriodization
A controlled trial found that progressing training by adding repetitions produced hypertrophy and strength gains similar to progressing by adding load, provided sets were taken near failure. Progressive overload can be delivered through either variable without loss of adaptation.
How Fibral applies it: Drive progressive overload by adding load or by adding reps at a fixed load; either method works as long as effort stays high.
Limits and applicability
No limitation statement has been published for this note yet. Treat it as a general evidence-informed rule, not an individualized guarantee.
- Plotkin D, Coleman M, Van Every D, et al. (2022). Progressive overload without progressing load? The effects of load or repetition progression on muscular adaptations View source
Approved content v3 · updated Aug 17, 2026
Meta-analysisPeriodization
A meta-analysis found that periodized resistance training produces greater maximal strength gains than non-periodized training, and reviews indicate both undulating and linear models work with no consistent superiority of one over the other. Structured variation of volume and intensity beats holding the same prescription indefinitely.
How Fibral applies it: Periodize training by planning progression and varying volume and intensity over time rather than repeating identical sessions; choose linear or undulating structure by preference.
Limits and applicability
No limitation statement has been published for this note yet. Treat it as a general evidence-informed rule, not an individualized guarantee.
- Williams TD, Tolusso DV, Fedewa MV, Esco MR (2017). Comparison of Periodized and Non-Periodized Resistance Training on Maximal Strength: A Meta-Analysis View source
Approved content v3 · updated Aug 17, 2026