Original articles  EXERCISE PHYSIOLOGY AND BIOMECHANICS 

The Journal of Sports Medicine and Physical Fitness 2005 March;45(1):1-6

Copyright © 2009 EDIZIONI MINERVA MEDICA

lingua: Inglese

Self selected speed and maximal lactate steady state speed in swimming

Baron B., Dekerle J., Depretz S., Lefevre T., Pelayo P.

Laboratoire d’Etudes de la Motricite Humaine Faculté des Sciences du Sport et de l’Education Physique University of Lille 2, Lille, France

Aim. The pur­pos­es of ­this ­study ­were to ascer­tain wheth­er phys­io­log­i­cal and strok­ing param­e­ters ­remain ­stable dur­ing a 2-­hour exer­cise per­formed at ­self-select­ed swim­ming ­speed (S4) and wheth­er ­this ­speed cor­re­sponds to ­those asso­ciat­ed ­with the max­i­mal lac­tate ­steady ­state (­SMLSS).
Methods. Ten ­well-­trained com­pet­i­tive swim­mers per­formed a max­i­mal 400-m ­front ­crawl ­test, 4 30-min swim­ming ­tests in ­order to deter­mine ­SMLSS and a 2-­hour ­test ­swum at ­their pre­ferred pac­es to deter­mine ­self-select­ed swim­ming ­speed (S4), ­stroke ­rate (SR4), and ­stroke ­length (SL4) ­defined as the ­mean val­ues ­observed ­between the 5th and the 15th min of ­this ­test. The strok­ing, meta­bol­ic and res­pir­a­to­ry param­e­ters, and rat­ings of per­ceived exer­tion (CR10) ­were report­ed through­out the 2-­hour ­test.
Results. S4 and ­Smlss ­were not sig­nif­i­cant­ly dif­fer­ent and ­were high­ly cor­re­lat­ed (r=0.891). S4 and SL4 ­decreased sig­nif­i­cant­ly ­after a ­steady ­state of 68 min and 100 min, respec­tive­ly, where­as SR4 ­remained con­stant. Mean V.O2, diox­ide out­put, and ­heart ­rate val­ues did not ­evolve sig­nif­i­cant­ly ­between the 10th and 120th min­ute of the ­test where­as cap­il­lary ­blood lac­tate con­cen­tra­tion ([La]) ­decreased sig­nif­i­cant­ly (p<0.05). Moreover, res­pir­a­to­ry CR10 did not ­evolve sig­nif­i­cant­ly ­between the 10th and the 120th min­ute of the ­test where­as gen­er­al CR10 and mus­cu­lar CR10 ­increased sig­nif­i­cant­ly.
Conclusion. Considering the [La], SL4 and CR10 val­ues vari­a­tions, mus­cu­lar param­e­ters and a prob­ably gly­co­gen­ic deple­tion ­seem to be the ­main lim­it­ing fac­tors ­that pre­vent main­tain­ing the ­self select­ed swim­ming ­speed.