Study data: Systematic massage prevents the increase in pain during 100-m freestyle sprint 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 single massage on perceptive outcomes were analyzed by generalized estimating equations (GEE) with ordinal distribution and cumulative logit link function. Intervention group, training time-points and day of application were used as predictors in the model. Dependent variables were rated by a 5-point likert scale and 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. Parameter estimates (B) and Exp(B) were reported along with 95% Confidence Intervals, descriptive data were reported as median with minimum and maximum values for categorical data and means with standard errors for continuous data. 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) . Results: Control had more chances of reporting extreme pain over the first stages of the swimming training (Exp(B)=5.88 CI95%=1.70, 20.28) while the chances for superficial and deep massage were not different throughout the training. Repeated bouts of superficial massage promoted more chances of reporting no pain over the sprint than deep massage (Exp(B)=6.19 CI95%=1.58, 24.15) and control (Exp(B)=4.93 CI95%=1.76, 13.83) but had effects over performance and functional outcomes. Pearson’s correlation showed no important influence of training load over performance (Sprint time r2=0.01 P=0.16; FINA Points r2=0.004 P=0.81). *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.