Biomechanics and Medicine in Swimming XI

BiomechanicsandmedicineinswimmingXi
these subjects since testing occurred at the beginning of re-training. After
three months of intensive training, however, these athletes were probably
able to accurately estimate the gap between their current best competitive
performance and that of the present experiment. More surprising,
then, is the lower “frustration” level found in the second test. This is only
speculative, but it may have been because these athletes knew what they
were capable of in competitive situations at that time and did not worry
that their performance in the experimental conditions was far from what
they did in competition.
Finally, it is interesting to note that in the different experimental conditions,
a difference in TWL was accompanied by an increase in [La-]
level in the comparisons of gender, age and distance swum. But whether
these changes were concomitant or the lactate increase was the consequence
of the change in TWL goes beyond the scope of this article.
conclusIon
The multi-dimensionality of the NASA-TLX questionnaire provides an
insight into sport performance. It might be a useful tool to determine the
characteristics of specific populations or to monitor change due to training
with more precision.
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288
Does the Y-Intercept of a Regression Line in the
Critical Velocity Concept Represent the Index for
Evaluating Anaerobic Capacity?
shimoyama, Y. 1 , okita, K. 1 , Baba,Y. 1 , sato, d. 1
1 Niigata University of Health and Welfare, Niigata, JAPAN
The purpose of the present study was to investigate whether the yintercept
of a regression line in the critical velocity concept could be
utilized as an index for evaluating anaerobic capacity. Twenty-one welltrained
college swimmers performed a maximum effort swim over 50,
100, 200 and 400m for modeling the distance-time (D-T) relationship
and measuring peak blood lactate concentration ([La]), and a 30-s allout
Wingate Anaerobic Test (WAnT) performed with arms and legs.
The y-intercept was significantly related to highest [La], the mean and
the peak power of the WAnT performed with both arms and legs. These
results suggest that the y-intercept is a valuable index for evaluating anaerobic
capacity using a non-invasive method in competitive swimming.
Key words: critical velocity concept, anaerobic capacity, y-intercept
IntroductIon
The accurate monitoring of both aerobic and anaerobic capacities is required
to make a training program effective (Maglischo 2003). Therefore,
several testing procedures have been presented in the literature to
measure [La] at sub-maximum intensities and VO 2 max (Bosquet et al.
2002) for evaluating the aerobic capacity, and to measure the highest
[La] (Lacour et al. 1990) and the maximal oxygen deficit (Ogita et al.
1996) for the anaerobic capacity. However, it is difficult to measure these
indices in the field, because they rely on the use of expensive equipment
and their method are invasive.
A linear relationship is observed between the total work performed
during an exhaustive maximal test and the time to exhaustion. In the
2-parameter model, the slope of the linear regression line has been
referred to as critical power (Monod and Scherrer 1965), which was
defined as the theoretical maximum power that could be maintained
without exhaustion for a long time. This critical power concept was applied
by Wakayoshi (1992) in swimming (the critical swimming velocity
concept). Wakayoshi et al.(1992) suggested that the slope of the linear
regression line between distance (D) and time required to cover it (T)
at maximal speed could be a critical velocity (CV). Further, there was a
positive correlation between the CV and 30-minute maximum swimming
velocity (Dekerle et al. 2002), LT (Martin et al. 2000), and the
velocity at [La] of 4 mmol.L -1 (V@OBLA; Wakayoshi et al. 1993). It
was therefore suggested that CV was a valuable index for evaluating the
aerobic capacity of swimmers using a non-invasive method.
On the other hand, the y-intercept of the regression line in the
critical power concept (Monod and Scherrer 1965) was called the anaerobic
work capacity (AWC) (Vandewalle et al. 1997). In previous studies,
AWC has been shown to be related to the highest [La] measured at the
end of exhausting running exercise (Vandewalle et al. 1997), the total
amount of work during the WAnT (Vandewalle et al. 1989) and the
maximal oxygen deficit (Miura et al. 2002). Therefore, it was suggested
that the y-intercept of the regression line in the critical power concept
would represent an index of anaerobic capacity.
In the critical swimming velocity concept, Oshita et al. (2009)
found a highly positive correlation between the y-intercept and the
residual error obtained from the relationship between 1500-m performance
and CV in Fin-swimming. Besides, when modeling the energetic
contribution in swimming, di Prampero et al. (2008) assumed that the y-