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document
Changes in H reflex and V wave following short-term endurance and strength training . This study examined the effects of 3 wk of either endurance or strength training on plasticity of the neural mechanisms involved in the soleus H reflex and V wave . Twenty-five sedentary healthy subjects were randomized into an endurance group ( n = 13 ) or strength group ( n = 12 ) . Evoked V-wave , H-reflex , and M-wave recruitment curves , maximal voluntary contraction ( MVC ) , and time-to-task-failure ( isometric contraction at 40 % MVC ) of the plantar flexors were recorded before and after training . Following strength training , MVC of the plantar flexors increased by 14.4 ± 5.2 % in the strength group ( P < 0.001 ) , whereas time-to-task-failure was prolonged in the endurance group ( 22.7 ± 17.1 % ; P < 0.05 ) . The V wave-to-maximal M wave ( V/M ( max ) ) ratio increased significantly ( 55.1 ± 28.3 % ; P < 0.001 ) following strength training , but the maximal H wave-to-maximal M wave ( H ( max ) /M ( max ) ) ratio remained unchanged . Conversely , in the endurance group the V/M ( max ) ratio was not altered , whereas the H ( max ) /M ( max ) ratio increased by 30.8 ± 21.7 % ( P < 0.05 ) . The endurance training group also displayed a reduction in the H-reflex excitability threshold while the H-reflex amplitude on the ascending limb of the recruitment curve increased . Strength training only elicited a significant decrease in H-reflex excitability threshold , while H-reflex amplitudes over the ascending limb remained unchanged . These observations indicate that the H-reflex pathway is strongly involved in the enhanced endurance resistance that occurs following endurance training . On the contrary , the improvements in MVC following strength training are likely attributed to increased descending drive and/or modulation in afferents other than Ia afferents .
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Intervention_Educational
short-term endurance and strength training .
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Intervention_Educational
endurance or strength training
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Intervention_Educational
endurance group
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Intervention_Physical
strength group
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Intervention_Educational
strength training
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Intervention_Physical
endurance training
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Outcome_Physical
MVC of the plantar flexors
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Outcome_Physical
V wave-to-maximal M wave ( V/M ( max ) ) ratio
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Outcome_Physical
maximal H wave-to-maximal M wave ( H ( max ) /M ( max ) ) ratio
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Outcome_Physical
the V/M ( max ) ratio
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Outcome_Physical
the H ( max ) /M ( max ) ratio
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Outcome_Physical
the H-reflex excitability threshold
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Outcome_Physical
H-reflex excitability threshold
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Outcome_Physical
ascending limb
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Outcome_Physical
enhanced endurance resistance
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Outcome_Other
improvements in
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Participant_Sample-size
Twenty-five