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Updated: Aug 6, 2026
Improving Strength, Power, Muscle Aerobic Capacity, and Glucose Tolerance through Short-term Progressive Strength Training Among Elderly People
Published on: July 5, 2017
Photobiomodulation as an Adjunct to Resistance Training in Older Adults: A Systematic Review and Meta-Analysis
Hongxiu Chen1, Wichai Eungpinichpong2,3, Somkiat Asawaphureekorn4
1Department of Exercise and Sport Sciences, Graduate School, Khon Kaen University, Khon Kaen, Thailand.
Background:
Photobiomodulation (PBM) has been proposed as an adjunct to resistance training to enhance strength adaptations; however, findings from randomized controlled trials (RCTs) remain inconsistent. This study aimed to evaluate whether adjunctive PBM improves maximal strength gains when combined with periodized resistance training in older adults.
Methods:
RCTs were identified through systematic searches of PubMed, Scopus, Embase, PEDro, Web of Science, the Cochrane Library, and CNKI from inception to January 2026. Eligible studies examined PBM delivered via low-level laser therapy or light-emitting diodes in combination with resistance training or other strength-oriented loading tasks. Prespecified meta-analyses were restricted to trials combining PBM with periodized resistance training that reported one-repetition maximum (1RM) outcomes; other studies were included in a narrative synthesis.
Results:
Eleven RCTs (n = 456) were included. Five trials (PBM plus resistance training: n = 74; control: n = 72) met the criteria for meta-analysis. PBM combined with resistance training did not significantly improve maximal muscle strength compared with sham PBM (SMD = 0.26, 95% CI -0.08 to 0.59; p = 0.14; I2 = 4%). Subgroup analyses showed a nonsignificant trend favoring PBM for unilateral 1RM, with no effect for bilateral outcomes and no significant subgroup differences. Sensitivity analyses indicated that the unilateral effect was dependent on individual studies. In nonresistance training contexts, some studies reported potential benefits for fatigue-, recovery-, or function-related outcomes, particularly in frail or critically ill older adults, although findings were inconsistent.
Conclusion:
Current evidence does not demonstrate a clear additional benefit of PBM on maximal strength when combined with resistance training in older adults, although a small effect cannot be excluded. PBM may have selective value in improving recovery-related outcomes and supporting training tolerance in vulnerable populations. Larger, well-designed RCTs are needed to clarify its role.
