Post-exercise Muscle Recovery Clinical Trial
Official title:
Isolated and Combined Effects of Phototherapy and Cryotherapy in Post-exercise Skeletal Muscle Recovery
Volunteers were divided randomly in five experimental groups. VAS (Visual Analogic scale) to
measure DOMS (Delayed Onset Muscle Soreness) and blood samples was taken before any
procedure. Then, volunteers performed stretching and warm-up followed by MVC test (isometric
test in isokinetic dynamometer to measure muscle function). After, volunteers performed the
exercise protocol (75 eccentric contractions) to lead to muscle fatigue. Immediately after
exercise protocol (1 minute) and 1 hour, 24, 48, 72 and 96 hours after, blood sample, VAS
measure and MVC test were repeated. The treatments according to randomisation were performed
three minutes after exercise protocol and it were performed again in 24, 48, 72h after
eccentric exercise.
The variables regarding to muscle function (MVC, DOMS) and the indirect marker of muscle
damage (CK activity) were monitored in all time points mentioned above (baseline, 1 minute,
1 hour, 24, 48, 72 and 96 hours after exercise protocol).
A randomized, double-blind, placebo-controlled clinical trial was performed at the
Laboratory of Phototherapy in Sport and Exercise at Nove de Julho University in the city of
São Paulo, Brazil.
Fifty healthy untrained male subjects were recruited from university staff and students to
participate in the study. All participants voluntarily must agree to participate and they
signed the informed consent statement. The intention-to-treat analysis was followed.
The volunteers were randomly allocated to five experimental groups (n=10 per group)
according to the applied comparator. Randomisation was carried out by a simple drawing of
lots (A, B, C, D or E). Blood samples (10 ml) was taken by a qualified nurse to analyse CK
activity posteriorly. This blood collection was repeated 1 minute, 1 hour, 24, 48, 72 and 96
hours after eccentric protocol.
A visual analogue scale (VAS) of 100 mm was used as a self-rating of volunteers DOMS
intensity, with assistance of a blinded researcher. DOMS assessments were performed at
baseline, immediately after eccentric exercise protocol (1 minute), and it was repeated at
1, 24, 48, 72 and 96 hours after the exercise protocol. Before exercise protocol, volunteers
will perform a stretching and warm-up of the non-dominant lower limb and then they will
perform Maximum voluntary contraction (MVC) to evaluate muscle function. MVC measurements
were repeated at the same time intervals as the CK measures.
The exercise protocol consists in 75 eccentric isokinetic contractions of the knee extensor
musculature in the non-dominant leg (5 sets of 15 repetitions, 30-second rest interval
between sets) at a velocity of 60°.seg-1 in both the eccentric and concentric movements with
a 60° range of motion (between 90° and 30° of knee flexion).
Regarding to treatment, all volunteers received the treatment according to randomisation
three minutes after eccentric exercise protocol. Comparators were repeated at 24, 48, and 72
hours following the collection of additional blood samples for CK analyses and MVC and DOMS
assessments.
The five groups was divided in: PBMT (photobiomodulation therapy)+cryotherapy;
cryotherapy+PBMT; active PBMT; placebo PBMT and only cryotherapy.
PBMT was applied employing a cordless, portable GameDay™ Super Pulsed Laser (manufactured by
Multi Radiance Medical, USA) to 6 sites of quadriceps femoris in direct contact with the
skin (2 centrally - rectus femoral and vastus intermedius; 2 laterally - vastus lateralis;
and 2 medially - vastus medialis) and cryotherapy was done with two flexible ice packs
filled with ice cubes and water (with a volume of 1.15 liters each) that will cover the
entire quadriceps for 20 minutes.
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Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Treatment