Training-Induced Muscle Adaptations During Competitive Preparation in Elite Female Rowers.

Stephan Van Der Zwaard,Guido Weide,Koen Levels,Richard T Jaspers,Mathijs J Hofmijster,Jos J De Koning,Tommie F P Koppens

doi:10.3389/fspor.2021.781942

Abstract

Training-induced adaptations in muscle morphology, including their magnitude and individual variation, remain relatively unknown in elite athletes. We reported changes in rowing performance and muscle morphology during the general and competitive preparation phases in elite rowers. Nineteen female rowers completed 8 weeks of general preparation, including concurrent endurance and high-load resistance training (HLRT). Seven rowers were monitored during a subsequent 16 weeks of competitive preparation, including concurrent endurance and resistance training with additional plyometric loading (APL). Vastus lateralis muscle volume, physiological cross-sectional area (PCSA), fascicle length, and pennation angle were measured using 3D ultrasonography. Rowing ergometer power output was measured as mean power in the final 4 minutes of an incremental test. Rowing ergometer power output improved during general preparation [+2 ± 2%, effect size (ES) = 0.22, P = 0.004], while fascicle length decreased (−5 ± 8%, ES = −0.47, P = 0.020). Rowing power output further improved during competitive preparation (+5 ± 3%, ES = 0.52, P = 0.010). Here, morphological adaptations were not significant, but demonstrated large ESs for fascicle length (+13 ± 19%, ES = 0.93), medium for pennation angle (−9 ± 15%, ES = −0.71), and small for muscle volume (+8 ± 13%, ES = 0.32). Importantly, rowers showed large individual differences in their training-induced muscle adaptations. In conclusion, vastus lateralis muscles of elite female athletes are highly adaptive to specific training stimuli, and adaptations largely differ between individual athletes. Therefore, coaches are encouraged to closely monitor their athletes' individual (muscle) adaptations to better evaluate the effectiveness of their training programs and finetune them to the athlete's individual needs.

Highlights

Training-induced adaptations are essential for elite athletes to optimize their performance in preparation to the World Championships or the Olympics
Stepwise multiple regression analysis revealed that changes in rowing ergometer power output were largely explained by the baseline values of muscle volume, pennation angle, and power output (R2 = 0.68, P < 0.01)
When baseline power output was excluded as a predictor, the change in rowing ergometer power output tended to be explained by the changes in muscle volume and baseline values of pennation angle (R2 = 0.32, P = 0.068)

Summary

Introduction

Recent studies have examined how such skeletal muscle characteristics are linked to the performance of athletes (van der Zwaard et al, 2018a,b). These studies show that muscle volume and architecture are important determinants for sprint and endurance performance of elite rowers and cyclists (van der Zwaard et al, 2018a,b). Muscle volume of the vastus lateralis, for example, largely explains differences in rowing ergometer performance in Olympic male and female rowers (van der Zwaard et al, 2018b). Insight into muscle adaptations that result from specific training interventions may deepen our understanding of how athletes can optimize their performance

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