Knowledge of Repetition Range Does Not Affect Maximal Force Production Strategies of Adolescent Females.
PURPOSE
Contrary to adult force reserve strategies, it is not known whether adolescent females with less experience performing maximal voluntary contractions (MVC) have specific responses to a known or unknown fatigue endpoint.


METHODS
Using a counterbalanced random crossover design, fourteen inexperienced female adolescents completed three elbow flexor (EF) fatiguing protocols. Participants were randomly assigned to a control (informed they would perform 12 MVCs), unknown (not informed of the number of MVCs to be completed, but stopped after 12) or deception condition (instructed to complete 6 MVCs, however, after the sixth repetition performed another 6 MVCs). Before and during the interventions, EF impulse, force, and biceps brachii (BB) and triceps brachii (TB) electromyography (EMG) activity were recorded.


RESULTS
Participants exhibited decreases in impulse (10.9%; p < .05), force (7.5%; p = .001), BB (16.2%; p < .05) and TB (12.9%; p < .05) EMG activity between the pretest and the first repetition of all protocols. Knowledge of endpoint, or lack of it, did not change measures with the repeated MVCs. When informed about the final repetition, force remained depressed suggesting no physiological reserve.


CONCLUSION
Adolescent females exhibited an anticipatory response to the task of performing repeated MVCs. A lack of change with knowledge of endpoint indicates that those lacking in MVC experience do not employ the same pacing strategies as in previous studies of participants with MVC experience.
['Reid|Jonathan C|JC|', 'Greene|Rebecca M|RM|', 'Herat|Nehara|N|', 'Hodgson|Daniel D|DD|', 'Halperin|Israel|I|', 'Behm|David G|DG|']
D000293:Adolescent D059031:Anticipation, Psychological D018592:Cross-Over Studies D004550:Elbow D004576:Electromyography D005260:Female D006801:Humans D007537:Isometric Contraction D018763:Muscle Fatigue D018482:Muscle, Skeletal
fatigue electromyography children girls strength