(6) INCREASES IN FOREARM FLEXION PEAK TORQUE FOLLOWING 4 DAYS OF ISOKINETIC RESISTANCE TRAINING IN WOMEN

Purpose: The purpose of this study was to examine the effects of 2, 3, and 4 days of maximal, concentric, reciprocal isokinetic forearm flexion (FF) and extension (FE) at 180°∙s^-1 on FF and FE peak torque (PT) during maximal voluntary isometric contractions (MVIC) and isokinetic muscle actions at 60, 180, and 300°∙s^-1 in untrained women. Methods: Seven women (mean ± SD: age: 21.6 ± 1.0 yrs; height: 169.3 ± 4.6 cm; body mass: 64.2 ± 6.9 kg) completed 4 days of maximal, concentric, reciprocal isokinetic FF and FE training at 180°∙s^-1 for 6 sets of 10 repetitions with the non-dominant arm (based on throwing preference). In addition, the subjects completed 4 testing visits (Pre-testing, following 2 days of training [Day 2], following 3 days of training [Day 3], and following 4 days of training [Day 4]) with the non-dominant arm that included 2 FF and 2 FE MVICs at an elbow joint angle of 90°, followed by 3, maximal, concentric, reciprocal isokinetic FF and FE muscle actions at each velocity (60, 180, and 300°∙s^-1). The highest PT values for the MVICs and isokinetic muscle actions at each velocity were used for analyses. Two separate 4 (Velocity: MVIC, 60, 180, and 300°∙s^-1) x 4 (Time: Pre-test, Day 2, Day 3, and Day 4) repeated measures ANOVAs were used to examine the training-induced changes in the FF and FE PT values and follow-up pairwise comparisons were used when necessary. Effect sizes were reported as partial eta-squared (η²_p) and Cohen’s d for the ANOVAs and pairwise comparisons, respectively. An alpha value of p ≤ 0.05 was considered statistically significant. Results: The results of the repeated measures ANOVA for FF PT indicated that there was no significant 2-way (p = 0.124, η²_p = 0.216) interaction, but a significant main effect for Time (p < 0.001, η²_p = 0.589) and Velocity (p < 0.001, η²_p = 0.923). Follow-up pairwise comparisons for FF PT (collapsed across Velocity), indicated that Day 4 PT (32.0 ± 5.9 Nm) was significantly greater (p = 0.001; d = 0.476; Bonferroni corrected alpha = 0.0083) than Pre-test PT (29.2 ± 5.9 Nm) and Day 2 PT (28.8 ± 6.1 Nm; p = 0.003; d = 0.533). For FE PT, results indicated no significant 2-way (p = 0.314, η²_p = 0.167) interaction or main effect for Time (p = 0.477, η²_p = 0.126), but a significant main effect for Velocity (p < 0.001, η²_p = 0.924). Conclusions: These findings indicated that 4 days of maximal, concentric, reciprocal isokinetic FF and FE training at 180°∙s^-1 was the minimum threshold required to increase FF PT at various velocities in untrained women, but was not sufficient to elicit increases in FE PT. Thus, future studies should continue to examine the minimum days of maximal, concentric, reciprocal isokinetic training at 180°∙s^-1 required to increase FE PT. Practical Applications: Utilizing short-term resistance training programs may be beneficial in clinical and/or athletic settings to increase strength in the upper body for those with limited time or resources. In addition, examining the effects of short-term resistance training may be useful for identifying sex-dependent and/or muscle action-dependent differences in the time course of changes in strength.
Acknowledgements: None.