Modeling the training-performance relationship using a mixed model in elite swimmers

Abstract

Purpose: The aim of this study was to model the relationship between training and performance in 13 competitive swimmers, over three seasons, and to identify individual and group responses to training.

Methods: A linear mixed model was used as an alternative to the Banister model. Training effect on performance was studied over three training periods: short-term, the average of training load accomplished during the 2 wk preceding each performance of the studied period; mid-term, the average of training load accomplished during weeks 3, 4, and 5 before each performance; and long-term, weeks 6, 7, and 8.

Results: Cluster analysis identified four groups of subjects according to their reactions to training. The first group corresponded to the subjects who responded well to the long-term training period, the second group to the long- and mid-term periods, the third to the short- and mid-term periods, and the fourth to the combined periods. In the model, the intersubject differences and the evolution over the three seasons were statistically significant for the identified groups of swimmers. Influence of short-term training was negative on performance in the four groups, whereas mid- and long-term training had, on the average, a positive effect in three groups out of four. Between seasons 1 and 3, the effect of mid-term training declined, whereas the effect of long-term training increased. The fit between real and modeled performances was significant for all swimmers (0.15 </= r2 </= 0.65; P </= 0.01).

Conclusion: The mixed model described a significant relationship between training and performance both for individuals and for groups of swimmers. This relationship was different over the 3 yr. Personalized training schedules could be prescribed on the basis of the model results.

FIGURE 1

Global weekly training load (the mean of the 7 intensity levels expressed in percentage of their maxima) for all the subjects, over the 3 seasons. Values are mean (SE). Discs in horizontal axis indicate main competitions. Over the 3 seasons, the 100% value was not attempted: there is no week in which the 100% value was attempted for all intensity levels and for all subjects.

FIGURE 2

Geometric representation of subjects (from S1 to S13) from the PCA. Factor 1 was negatively related to correlation between the short- and mid-term training periods with performance. Factor 2 was positively related to correlation between the long training period and performance. Groups: Poor responders to the short- or mid-term training and neutral to the long-term training (PN); Good responders to the short-, mid- and long-term training (GG); Good responders to the short- or mid-term training and poor to the long-term training (GN); Neutral responders to the short- or mid-term training and good to the long-term training (NG).

FIGURE 3

Real and modeled performance for subject 1 (A) and subject 7 (B). Performance in vertical axis is expressed in % of the personal record. Time in horizontal axis is expressed in weeks and seasons (crosses separate 1^st from 2^nd and 2^nd from 3^rd seasons). Real performance is indicated with stars linked by straight lines. Modeled performance is indicated by an irregular prediction curve and by diamonds for weeks where an actual performance took place. The 95% confidence intervals for the last case are also represented. For subject 1, the pattern of modeled performance is similar to that of real performance. Inversely, for subject 7, optimal modeled performance was situated shortly after the main seasonal competition, corresponding to the last event of the first and second season (weeks 40 and 98), indicating probably the need of a longer recovery.