Effects of Systematic Massage Application on Swimming Athletes Performance: a Randomized, Placebo-controlled Clinical Trial

The study was composed by a convenience sample of 19 male and female athletes aged between 12 and 20 years old who train regularly (six days a week) and are members of the Prudentina Athletic Sports Association (APEA) swimming team. The research project was accepted by the Research Ethics Committee of the Faculty of Science and Technology of the Paulista State University "Júlio de Mesquita Filho" - FCT / UNESP. A single-blinded crossover randomized controlled trial with 1:1:1 allocation. The sample was submitted to a balanced-block randomization, by sorting on Excel, with a balanced sex, age and competitive level ratio, to three sequences of interventions containing: (i) control, (ii) superficial massage and iii) deep massage. The study was conducted over a period of eight weeks, consisting of five sessions of resistance and swimming training. The option for intervention time point was based on a pilot study that yielded higher training loads on on Mondays, Tuesdays and Fridays and worse perceptions between both training stimuli (resistance and swimming). At the end of each training week, participants were subjected to a maximum test of 100-m front crawl sprint in a semi-olympic indoor pool (25 meters), then we performed a functional evaluation. Training load was monitored over the entire trial by the Session Rating of Perceived Exertion (sRPE) calculated by the product of the training duration and perception of effort. Effects of single massage on perceptive outcomes were analyzed by generalized estimating equations (GEE) with ordinal distribution and cumulative logit link function, using intervention group, training time-points and day of intervention as predictors in the model. The first category (nothing) was used as reference unless otherwise stated. Effects of repeated massage on proprioception was analyzed by GEE and remaining outcomes were analyzed by Generalized Linear Mixed Model, both with Gamma distribution and cumulative logit link function. Bonferroni adjustments were used for all significant main effect. Pearson's test was used to explore the correlation between training load and performance and interpreted as small (0.00-0.25), fair (0.26-0.50), moderate to good (0.51-0.75) and excellent (>0.75).