Original articles   

The Journal of Sports Medicine and Physical Fitness 2000 June;40(2):96-102

Copyright © 2002 EDIZIONI MINERVA MEDICA

lingua: Inglese

Time limit and time at V.O2max, during a continuous and an intermittent run

Demarie S. ^{1, 3}, Koralsztein J. P. ², Billat V. ^{1, 2}

From the 1 Laboratoire d’étude de la motricité humaine Université Lille 2 2 Centre de Médecine du Sport, Paris 3 Rome University Institute of Sport Sciences

Background. The pur­pose of ­this ­study was to ver­i­fy, by ­track ­field ­tests, wheth­er sub-­elite run­ners (n=15) ­could (i) ­reach ­their V·O2maxwhile run­ning at v50%∆, i.e. mid­way ­between the ­speed asso­ciat­ed ­with lac­tate thresh­old (vLAT) and ­that asso­ciat­ed ­with max­i­mal aero­bic pow­er (vV·O2max), and (ii) if an inter­mit­tent exer­cise pro­vokes a max­i­mal and/or ­supra max­i­mal oxy­gen con­sump­tion long­er ­than a con­tin­u­ous one.
Methods. Within ­three ­days, sub­jects under­went a mul­ti­stage incre­men­tal ­test dur­ing ­which ­their vV·O2max and vLAT ­were deter­mined; ­they ­then per­formed two addi­tion­al test­ing ses­sions, ­where con­tin­u­ous and inter­mit­tent run­ning exer­cis­es at v50%∆ ­were per­formed up to exhaus­tion. Subject’s gas ­exchange and ­heart ­rate ­were con­tin­u­ous­ly record­ed by ­means of a tele­met­ric appa­ra­tus. Blood sam­ples ­were tak­en ­from fin­ger­tip and ana­lysed for ­blood lac­tate con­cen­tra­tion.
Results. In the con­tin­u­ous and the inter­mit­tent ­tests ­peak V·O2 exceed­ed V·O2max val­ues, as deter­mined dur­ing the incre­men­tal ­test. However in the inter­mit­tent exer­cise, ­peak V·O2, ­time to exhaus­tion and ­time at V·O2max ­reached sig­nif­i­cant­ly high­er val­ues, ­while ­blood lac­tate accu­mu­la­tion ­showed sig­nif­i­cant­ly low­er val­ues ­than in the con­tin­u­ous one.
Conclusions. The v50%∆ is suf­fi­cient to stim­u­late V·O2max in ­both inter­mit­tent and con­tin­u­ous run­ning. The inter­mit­tent exer­cise ­results bet­ter ­than the con­tin­u­ous one in increas­ing max­i­mal aero­bic pow­er, allow­ing long­er ­time at V·O2max and obtain­ing high­er ­peak V·O2 with low­er lac­tate accu­mu­la­tion