Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT06252467 |
Other study ID # |
708.362 |
Secondary ID |
|
Status |
Completed |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
July 14, 2014 |
Est. completion date |
October 11, 2023 |
Study information
Verified date |
February 2024 |
Source |
Federal University of Rio Grande do Sul |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
The goal of this study was to investigate the effects of Photobiomodulation therapy (PBMT) on
performance, oxygen uptake (VO2 kinetics), and lower limb muscle oxygenation during three
successive time-to-exhaustion tests (TTEs) in cyclists. This was a double blind, randomized,
crossover, placebo-controlled trial study. Sixteen cyclists (~23 years old), with a cycling
training volume of ~460 km/week, volunteered for this study. In the first session, cyclists
performed a maximal incremental test to determine maximal oxygen uptake and maximal power
output (POMAX). In the following sessions, cyclists performed three consecutive TTEs at
POMAX. Before each test, PBMT (135 J/thigh) or a placebo (PLA) PBMT was applied to both
thighs. VO2 amplitude, O2 deficit, time delay, oxyhemoglobin (O2Hb), deoxyhemoglobin (HHb),
and total hemoglobin (tHb) were measured during tests on the right vastus lateralis. The
PBMT, applied before three successive TTE, increased performance of the first and second TTE
(~10-12%) tests, speed of VO2 and HHb kinetics during the first test, and increased
peripheral muscle oxygenation (increase in HHb and tHb) in the first and second exhaustion
tests. However, the PBMT effects were attenuated in the third TTE, as performance and all the
other outcomes were similar to the ones from the PLA intervention. In summary, PBMT
application increased the first and second successive TTEs, speed of VO2, and muscle
oxygenation.
Description:
The goal of this study was to investigate the effects of Photobiomodulation therapy (PBMT) on
performance, oxygen uptake (VO2 kinetics), and lower limb muscle oxygenation during three
successive time-to-exhaustion tests (TTEs) in cyclists. Our study was characterized as a
crossover, randomized, double-blind trial (blinding of the cyclists and the researcher
responsible for evaluations). All protocols were explained to the participants, who
voluntarily provided their consent to participate in the investigation through an informed
consent document. This study received approval from the Research Ethics Committee for Human
Subjects Studies at the institution where the research was conducted (number 708.362).
Inclusion criteria involved cyclists aged 18-30 years, with a competitive history and no
history of musculoskeletal injuries in the lower limbs in the last two years. Exclusion
criteria included chronic disease, smoking, metabolic disorders, use of steroids in the last
six months, chronic disease, physical disabilities, and use of antibiotic drugs in the
previous week. The cyclists participating in the present study had ~6.5 years of regular
training/competition and no history of lower limb muscular and/or skeletal injuries. Each
cyclist visited the laboratory on three occasions. At the first visit, cyclists performed a
maximum incremental test and familiarization to three successive TTEs. At the two subsequent
visits, participants performed a standard protocol of three successive TTEs at maximal power
output (POMAX) with preferred cadence, and PBMT or placebo (PLA) treatments were applied
before each trial. The three testing days were performed with a 72h interval apart. A single
therapist was involved with the random allocation of the PBMT and PLA interventions. This
therapist received instructions not to disclose the treatment modality employed during each
assessment session to either the cyclists or other researchers involved with data collection
and data analysis. Furthermore, cyclists utilized opaque eyewear to shield their eyes and
obstruct their visual access (visual blinding) during the PBMT or PLA intervention. The
therapist was explicitly advised against revealing the treatment modality to both the
cyclists and the other researchers. PBMT did not elicit any thermal or tactile sensations,
thereby ensuring that athletes remained unaware of the specific application on their thigh
area. The random assignment was determined through a basic drawing of lots during the first
testing session, determining the allocation of either active PBMT or inactive PLA.