Training Load Is Correlated with Changes in Creatine Kinase and Wellness over a 12-Week Multi-Stage Preparatory Training Block for a Major Competition in International Boxers

Background: There are no published data on the training-load magnitude or distribution in elite international-level boxers preparing for a major competition nor on the training load’s relationship with objective and subjective training markers. Methods: Twelve elite boxers (eight males and four females) preparing for the 2018 Commonwealth Games were monitored during training for 12 weeks. The training load (TL), change in creatine kinase (ΔCK), and wellness variables were measured daily but were amalgamated into average weekly values over the 12-week period for weekly comparisons. The relationships between the TL, ΔCK, and wellness variables were also assessed. Results: The significant (p < 0.001) main effects of the week with large and moderate effect sizes were noted for the TL and ΔCK, respectively, with weeks 9 and 12 in the competition-specific and taper phases showing the greatest differences, respectively. For wellness, only the muscle condition showed a significant change over time (p < 0.001). There were significant (p < 0.05) small–moderate correlations between the TL, ΔCK, and wellness variables. Conclusions: This is the first study to describe the weekly training loads and responses to training of elite international boxers across a 12-week pre-competition training period in preparation for a major competition. The findings within this study report that elite international boxers have high chronic training loads that change between training blocks to put emphasis on different qualities. Monitoring the indirect muscle damage through CK may provide further information on the internal training responses in boxers.