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| Name | Class |
|---|---|
| Fundação de Amparo à Pesquisa do Estado de São Paulo | OTHER_GOV |
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In last years it has been demonstrated that photobiomodulation therapy (PBMT) has ergogenic effects, improving muscular performance and accelerating post-exercise recovery. However, many aspects related to these effects and its' clinical applicability remain unknown. Therefore, the aim of this project is to evaluate the ergogenic effects of PBMT in detraining after a strength training protocol.
It will be carried out a randomized, triple-blind, placebo-controlled trial.
Forty-eight volunteers will be randomly allocated to four experimental groups:
The individuals randomly allocated to the different groups will be subjected to 12 consecutive weeks of dynamic strength training involving leg-press and knee extension exercises in leg-press and leg-extension machines, respectively, 2 times a week.After the 12-week training period, the volunteers will receive the application of PBMT or placebo depending on the group to which they are allocated for 4 weeks (2 times a week) without training.
The data will be collected by a blind assessor. It will be analyzed the muscular strength and the structural properties of quadriceps before starting the study (baseline), at 4, 8, and 12 weeks after starting the training period, and at 4 weeks after completing the training (detraining period), in both lower limbs.
The findings will be tested for their normality using the Shapiro-Wilk test. Parametric data will be expressed as mean and standard deviation and non-parametric data as median and respective upper and lower limits. Parametric data will be analyzed by two-way repeated measures analysis of variance (ANOVA; time versus experimental group) with post-hoc Bonferroni correction. Non-parametric data will be analyzed using the Friedman test and, secondarily, the Wilcoxon signed-rank test. Data will be analyzed in terms of both their absolute values and their relationship to the percentage change based on the values established in the baseline tests. The significance level will be set at p<0.05.
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| PBMT + training/ PBMT + detraining | Experimental | PBMT applied before the strength training sessions (12 weeks, 2 times a week) and PBMT applied during the detraining period (4 weeks, 2 times a week). |
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| PBMT + training/ placebo + detraining | Experimental | PBMT applied before the strength training sessions (12 weeks, 2 times a week) and placebo applied during the detraining period (4 weeks, 2 times a week). |
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| Placebo + training/ PBMT + detraining | Experimental | Placebo applied before the strength training sessions (12 weeks, 2 times a week) and PBMT applied during the detraining period (4 weeks, 2 times a week). |
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| Placebo + training/ placebo + detraining | Placebo Comparator | Placebo applied before the strength training sessions (12 weeks, 2 times a week) and placebo applied during the detraining period (4 weeks, 2 times a week). |
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| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| PBMT | Device | PBMT will be applied bilaterally using the direct contact method with light pressure on the skin to 6 sites of the anterior thigh (2 medial, 2 lateral, and 2 central). A 12-diode cluster, with 4 905-nm laser diodes (12.5W peak power for each diode), 4 875-nm LED diodes (17.5 mW mean power for each diode), and 4 640-nm LED diodes (15 mW mean power for each diode), manufactured by Multi Radiance Medical® (Solon, OH, USA), will be used to apply the PBMT. The dose used for applications during the training and/or detraining periods will be 30 Joules (J) per site (180 J per thigh). PBMT will be applied before each workout and during the detraining period, depending on the group to which the volunteers are allocated. |
| Measure | Description | Time Frame |
|---|---|---|
| Peak Torque | The peak torque will be measured by Maximum Voluntary Contraction (MVC) test. | 16 weeks - 4 weeks after completing the training (detraining period). |
| Measure | Description | Time Frame |
|---|---|---|
| Peak Torque | The peak torque will be measured by Maximum Voluntary Contraction (MVC) test. | 4, 8, and 12 weeks after starting the training period. |
| Muscle strength | Muscle strength will be measured by one-repetition maximum (1-RM) test. |
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Inclusion Criteria:
Exclusion Criteria:
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| Name | Affiliation | Role |
|---|---|---|
| Ernesto Cesar Pinto Leal Junior, PhD | University of Nove de Julho | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Laboratory of Phototherapy and Innovative Technologies in Health | São Paulo | São Paulo | 01504-001 | Brazil |
| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| 41393334 | Derived | de Paiva PRV, Tomazoni SS, Machado CDSM, Pereira AL, Ribeiro NF, Lino MMA, Dias LB, de Oliveira MFD, de Araujo-Silva OM, Dorneles MP, Vanin AA, Baroni BM, Bjordal JM, Casalechi HL, Leal-Junior ECP. Effects of photobiomodulation therapy combined with static magnetic field on training adaptations and detraining responses: a randomised placebo-controlled trial. BMJ Open Sport Exerc Med. 2025 Dec 12;11(4):e002799. doi: 10.1136/bmjsem-2025-002799. eCollection 2025. | |
| 31662370 |
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Data will be shared upon request addressed to the principal investigator.
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A researcher will program the device (placebo or PMBT) and will be instructed not to inform the volunteers or other researchers as to the type of treatment (PMBT or placebo). Therefore, the researcher responsible for the treatment will be blinded to the type of treatment being administered to the volunteers. The sounds and signals emitted from the device as well as the information displayed on the screen will be identical, regardless of the type of treatment (placebo or PBMT).
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| Placebo | Device | Placebo PBMT will be applied bilaterally using the direct contact method with light pressure on the skin to 6 sites of the anterior thigh (2 medial, 2 lateral, and 2 central). The placebo PBMT will per performed using the dose of 0 J per diode. The sounds and signals emitted from the device as well as the information displayed on the screen will be identical, regardless of the type of treatment (active or placebo). Placebo PBMT will be applied before each workout and during the detraining period, depending on the group to which the volunteers are allocated. |
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| 4, 8, and 12 weeks after starting the training period, and at 4 weeks after completing the training (detraining period). |
| Muscle thickness | Muscle thickness will be measured by ultrasound imaging. | 4, 8, and 12 weeks after starting the training period, and at 4 weeks after completing the training (detraining period). |
| Muscle fascicle length | Muscle fascicle length will be measured by ultrasound imaging. | 4, 8, and 12 weeks after starting the training period, and at 4 weeks after completing the training (detraining period). |
| Muscle fiber pennation angle | Muscle fiber pennation angle will be measured by ultrasound imaging. | 4, 8, and 12 weeks after starting the training period, and at 4 weeks after completing the training (detraining period). |
| Derived |
| de Paiva PRV, Casalechi HL, Tomazoni SS, Machado CDSM, Vanin AA, Baroni BM, de Carvalho PTC, Leal-Junior ECP. Effects of photobiomodulation therapy combined to static magnetic field in strength training and detraining in humans: protocol for a randomised placebo-controlled trial. BMJ Open. 2019 Oct 28;9(10):e030194. doi: 10.1136/bmjopen-2019-030194. |