Study data: Repeated systematic massage improves perceptive outcomes over training sessions in young swimmers: A Randomized Controlled Clinical Trial
This study aimed to investigate the effects of repeated bouts of massage, adjusted to swimmer’s training on perceptive, functional and performance outcomes over a sprint and the effects of single bout of short massage on swimmer’s self-reported perceptions after resistance training. This cross-over randomized controlled trial with concealed allocation, assessor blinding and intention-to-treat analysis included 19 male and female competitive swimmers between 12 and 20 years old. Participants were subjected to three 12 min interventions (control, superficial or deep massage) over a week between a resistance and a swimming training and monitored regarding training load and perceptions. After the intervention week we assessed: perceptive (well-being, heaviness, tiredness, discomfort and pain), performance (Sprint time, FINA Points, Stroke characteristics), functional (Flexibility, Squat Jump, Bench press, Proprioception), beliefs and preferences. Analysis: Effects of massage on functional and performance outcomes were analyzed by Generalized Linear Mixed Model with Gamma distribution and cumulative logit link function, while perceptive outcomes were analyzed by Generalized Estimating Equations with ordinal distribution and cumulative logit link function. Dependent variables were rated by a 5-point likert scale and the first category (nothing) was used as reference unless otherwise stated. Intervention, group and training time-points were used as predictors in the repeated massage models, and for the single massage model, the weekday was also considered. Bonferroni adjustments were used for all significant main effects. Parameter estimates (B) and Exp(B) were reported along with 95% Confidence Intervals, descriptive data were reported as means and standard deviation (SD). 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). All analysis assumed level of significance of p<0.05. Results: It was found that SM had more chances of reporting no pain than CON and DM over the sprint. CON had more chances of reporting extreme pain at the beginning of the swimming training (Exp(B)=5.88 CI95%=1.70, 20.28) while SM and DM were not different throughout the training. SM and DM had no effects over performance and functional outcomes. We concluded that single and repeated massage have small significant effects over perceptive outcomes but did not improve swimming performance. *The dataset is as entered in SPSS for Generalized Linear Mixed Model analyses. **Functional and performance data are in ANOVA format as well to facilitate use by other reseachers.