NEUROMUSCULAR ADAPTATIONS FOLLOWING PREPUBESCENT STRENGTH TRAINING

Underlying mechanisms of prepubescent strength gains following resista nce training are speculative. The purpose of this investigation was to determine the effects of 8 wk of resistance training on muscular stre ngth, integrated EMG amplitude (IEMG), and arm anthropometrics of prep ubescent youth. Sixteen subjects (8 males, 8 females) were randomly as signed to trained;or control groups. All subjects (mean age = 10.3 yr) were of prepubertal status according to the criteria of Tanner. The t rained group performed three sets (7-11 repetitions) of bicep curls wi th dumbbells three times per week for 8 wk. Pre- and posttraining meas urements included isotonic and isokinetic strength of the elbow flexor s, arm anthropometrics, and IEMG of the biceps brachii. Planned compar isons for a 2 x 2 (group by test) ANOVA model were used for data analy sis. Significant isotonic (22.6%) and isokinetic (27.8%) strength gain s were observed in the trained group without corresponding changes in arm circumference or skinfolds. The IEMG amplitude increased 16.8% (P < 0.05). The control group did not demonstrate any significant changes in the parameters measured. Early gains in muscular strength resultin g from resistance training by prepubescent children may be attributed to increased muscle activation.