REF-684 · Harries, Lubans & Callister, 2015 · Journal of Strength and Conditioning Research, · Paper · PubMed
Linear and undulating periodization showed no difference in upper- or lower-body strength gains across 17 head-to-head studies
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Key Findings
Search of MEDLINE, SCOPUS and SPORTDiscus: 17 studies directly comparing linear and undulating periodized resistance training; 510 participants in total.
16 studies reported significant strength increases with both approaches; 5 reported a significant difference between groups.
The meta-analyses found no difference between linear and undulating periodization for upper-body or lower-body strength.
The short-term nature of the studies and participants' previous training history were flagged as potential confounders; the authors suggest novelty or training variety matter for further strength development.
Practical Application
Pooling 17 studies (510 participants) that compared them head to head, linear and undulating periodization produced no difference in upper- or lower-body strength gains — choose the model by preference, schedule and adherence.
The authors point to novelty and variety as what drives further strength gains; change the stimulus periodically whichever model you use.
Limitations
Mostly short-term studies; previous training history may confound results.
"No difference" is not a formal equivalence test.
Few studies in adolescents or athletes.
How this entry was checked and changed
Why this level
regraded 2026-09-27 from B+: SR/MA of 17 mostly small, short-term trials
Content correction 2026-09-27
"Statistically equivalent gains when volume and intensity were matched" -> the abstract reports no difference in the meta-analyses; matching and equivalence testing are not stated.
Added 17 studies / 510 participants, the 16-of-17 and 5-of-17 counts and the confounders; level B+ -> A- (SR/MA of mostly small trials).
PMID 25353081 -> 25268290, the PubMed record returned by searching this DOI.