Performance and Muscle Architecture Comparisons Between Starters and Nonstarters in National Collegiate Athletic Association Division I Women's Soccer

Jajtner, AR, Hoffman, JR, Scanlon, TC, Wells, AJ, Townsend, JR, Beyer, KS, Mangine, GT, McCormack, WP, Bohner, JD, Fragala, MS, and Stout, JR. Performance and muscle architecture comparisons between starters and nonstarters in National Collegiate Athletic Association Division I women's soccer. J Strength Cond Res 27(9): 2355-2365, 2013This study compared performance and muscle architecture (MA) changes in starters (S) and nonstarters (NS) during a National Collegiate Athletic Association Division I women's soccer season. Twenty-eight women (19.9 +/- 1.1 years; 1.71 +/- 0.08 m; 64.7 +/- 6.4 kg) were monitored for vertical jump power (VJP), repeated line drills (LDs), 3-dimensional multiple object tracking (3D-MOT), and reaction time (RT) at preseason, midseason, and postseason. Muscle architecture changes using ultrasonography were assessed at preseason and postseason. Comparisons between S (n = 11; 70.0 +/- 14.6 min per game) and NS (n = 17; 8.4 +/- 8.0 min per game) were performed to make magnitude-based inferences. No differences were seen in VJP during the season in either group. Starters were more likely (81.1%) to decrease LD time than NS, with no differences in fatigue rate. Starters and NS improved 3D-MOT (1.14 +/- 0.41 to 1.55 +/- 0.43) and RT (0.37 +/- 0.05 to 0.34 +/- 0.33 seconds), with no differences between groups. Rectus femoris (RF) echo intensity improved (65.57 +/- 1.50 to 61.26 +/- 1.59) in both groups, with no interactions observed. Cross-sectional area (20.84 +/- 3.58 to 21.46 +/- 3.66 cm(2)) increased and pennation angle (PANG) (12.58 +/- 2.56 to 11.78 +/- 2.03 degrees) decreased for both groups in the vastus lateralis (VL). Muscle architecture comparisons between groups revealed S likely decreased VL muscle thickness (MT) and PANG (81.6 and 79.4%, respectively) and possibly decreased RF MT and PANG (65.7 and 59.4%, respectively) when compared with NS. Results indicate that VJP and LD fatigue rate are not changed during a competitive season, but S become faster than NS. Three-dimensional multiple object tracking and RT improve regardless of playing time. Changes in MA indicate that practices alone provide sufficient stimulus for improving muscle quality during the competitive season.