ORIGINAL ARTICLES   

The Journal of Sports Medicine and Physical Fitness 1999 December;39(4):294-9

Copyright © 2000 EDIZIONI MINERVA MEDICA

lingua: Inglese

The effects of rest interval on quadriceps torque and perceived exertion in healthy males

Pincivero D. M. ¹, Gear W. S. ², Moyna N. M. ³, Robertson R. J. ⁴

¹ Department of Physical Therapy, Eastern Washington University, Cheney, WA; ² Department of Physical Education, Recreation, and Dance California State University, Dominguez Hills; ³ Nuclear Cardiology, Hartford Hospital; ⁴ Human Energy Research Laboratory, University of Pittsburgh, PA

Back­ground. The ­ability to gen­erate max­imal mus­cular ­force is depen­dant ­upon ­time medi­ated mech­a­nisms of ­fatigue. ­Inter-set ­rest ­interval ­length may not ­only ­affect ­force pro­duc­tion but may ­also man­i­fest ­changes in rat­ings of per­ceived exer­tion (RPE). The pur­pose of ­this ­study was to ­examine the ­effects of ­rest ­interval on quad­ri­ceps ­torque and RPE ­during mul­tiple ­sets of ­resisted ­knee exten­sions.
­Methods. 14 ­healthy ­male vol­un­teers ­were ­assessed for con­cen­tric iso­ki­netic quad­ri­ceps ­peak ­torque, ­total ­work, and ­average ­power on the ­Biodex ­System II Iso­ki­netic Dyna­mom­eter at a preset ­angular ­velocity of 180 deg·sec-1. Per­ceived exer­tion was meas­ured ­with a mod­i­fied cat­e­gory-­ratio ­scale (CR-10). ­Under iso­metric con­di­tions the per­cep­tual ­range was ­anchored ­with one ­high and two low ­anchors. Sub­jects ­were ran­domly ­assigned to one of two ­groups: ­short ­rest ­interval (­Group 1, 40 sec) and ­long ­rest ­interval (­Group 2, 160 sec). All sub­jects per­formed 4 ­sets of 20 max­imal iso­ki­netic con­trac­tions ­with an ­inter-set ­rest ­interval ­that cor­re­sponded to ­their ­group assign­ment. Fol­lowing the com­ple­tion of ­each set sub­jects ­were ­asked to ­assign a ­rating out of 10 to the feel­ings in ­their quad­ri­ceps by vis­u­ally ­observing a ­chart of the CR-10 ­scale.
­Results. The ­results dem­on­strated a sig­nif­i­cantly ­greater ­decline in quad­ri­ceps ­peak ­torque (p<0.05), ­total ­work (p<0.05), and ­average ­power (p<0.05) by ­Group 1 as com­pared to ­Group 2. ­Changes in RPE ­across the 4 ­sets of exer­cise did not ­show a sig­nif­i­cant dif­fer­ence ­between the 2 ­groups.
Con­clu­sions. The gen­er­a­tion of quad­ri­ceps ­torque is a func­tion of ­rest ­interval ­length, ­whereas per­ceived exer­tion ­appears to be unaf­fected.