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					Fatigue tresholds in 30s water and land exercises performed by swimmers
Soares, S. ; Aleixo, I.; Santos, I.; Machado, L.; Maia, J.; Vilas-Boas, J. P.
Faculty of Sport, University of Porto

Determination of fatigue thresholds in order to evaluate swimming performance and to make an
efficient training control seems to be possible only in mixed or dominantly aerobic efforts. In this
field it’s very well none the anaerobic threshold. The study of fatigue thresholds in efforts of
anaerobic domain is something unusual. This is probably due to the some lack of knowledge
associated to anaerobic performance, once tests who most directly evaluate it (e. g. Biopsy or
Nuclear Magnetic Resonance) are expensive, invasive and not applicable in sports field. The
most widely accepted anaerobic test is the cycloergometer Wingate test. Although, Wingate is
very unspecific for swimmers and other tests must be found for evaluate this capacity. The aim of
the present study was to find and compare fatigue thresholds in velocity, force and power 30s
curves produced by swimmers. 90 swimmers, 30 pre-pubertal, 30 pubertal and 30 post-pubertal,
being 15 males and 15 females in each group, participate in the study. Pubertal stages were
defined using stages described by Tanner (1962). Experimental procedures consisted on five 30s
tests: (I) free swimming with the swimmers connected to a velocimetric system; (II) fully tethered
swimming; (III) simulated swimming on a biokinetic swim bench; (IV) crank ergometer Wingate
test and (V) cycloergometer Wingate test. Two especially developed MatLab programs allowed to
determine fatigue thresholds on the continuous 30s efforts of the tree first tests (Soares et al.,
2006) and of the two Wingate tests. It was possible to observe the existence of velocity, force and
power curves with one and two fatigue thresholds. In curves with one threshold fatigue appears at
13s of the beginning of the effort. In curves with two fatigue thresholds first appears at 8 and
second at 18s of the beginning of the effort. We could conclude that fatigue thresholds
appearance seems to be independent of the kind of effort performed by swimmers.
Soares, S.; Machado, L.; Lima, A.; Santos, I.; Fernandes, R.; Correia, M.; Maia, J.;
Vilas-Boas, J.P. (2006). Velocimetric characterization of a 30 sec maximal test in
swimming: consequences for bioenergetical evaluation. In: J.P. Vilas-Boas; F. Alves; A.
Marques (Eds.), Biomechanics and Medicine in Swimming X, 265-268. Revista
Portuguesa de Ciências do Desporto, 6: supl. 2, Porto, Portugal.
Tanner, J.; Whitehouse, R.; Healy, M. (1962). A new system for estimating skeletal
maturity for the hand and wrist, with standards derived from a study of 2.600 healthy
british children. Paris: Centre International de l'enfance.

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