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dc.contributor.authorPitt, Brynlynn
dc.contributor.authorDotan, Raffy
dc.contributor.authorMillar, Jordan
dc.contributor.authorLong, Devon
dc.contributor.authorTokuno, Craig
dc.contributor.authorO'Brien, Thomas
dc.date.accessioned2015-07-09T16:54:12Z
dc.date.available2015-07-09T16:54:12Z
dc.date.issued2015-01-15
dc.identifier.issn1439-6319
dc.identifier.other10.1007/s00421-015-3100-5
dc.identifier.urihttp://hdl.handle.net/10464/6944
dc.description.abstractAbstract Background Children have been shown to have higher lactate (LaTh) and ventilatory (VeTh) thresholds than adults, which might be explained by lower levels of type-II motor-unit (MU) recruitment. However, the electromyographic threshold (EMGTh), regarded as indicating the onset of accelerated type-II MU recruitment, has been investigated only in adults. Purpose To compare the relative exercise intensity at which the EMGTh occurs in boys versus men. Methods Participants were 21 men (23.4 ± 4.1 years) and 23 boys (11.1 ± 1.1 years), with similar habitual physical activity and peak oxygen consumption (VO2pk) (49.7 ± 5.5 vs. 50.1 ± 7.4 ml kg−1 min−1, respectively). Ramped cycle ergometry was conducted to volitional exhaustion with surface EMG recorded from the right and left vastus lateralis muscles throughout the test (~10 min). The composite right–left EMG root mean square (EMGRMS) was then calculated per pedal revolution. The EMGTh was then determined as the exercise intensity at the point of least residual sum of squares for any two regression line divisions of the EMGRMS plot. Results EMGTh was detected in 20/21 of the men (95.2 %) and only in 18/23 of the boys (78.3 %). The boys’ EMGTh was significantly higher than the men’s (86.4 ± 9.6 vs. 79.7 ± 10.0 % of peak power output at exhaustion; p < 0.05). The pattern was similar when EMGTh was expressed as percentage of VO2pk. Conclusions The boys’ higher EMGTh suggests delayed and hence lesser utilization of type-II MUs in progressive exercise, compared with men. The boys–men EMGTh differences were of similar magnitude as those shown for LaTh and VeTh, further suggesting a common underlying factor.en_US
dc.language.isoenen_US
dc.publisherSpringeren_US
dc.subjectChildrenen_US
dc.subjectExerciseen_US
dc.subjectMotor unit activationen_US
dc.titleThe electromyographic threshold in boys and menen_US
dc.typeArticleen_US


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