Swimming bodysuit in all-out and constant-pace trials

Abstract

There is no doubt that many swimmers do benefit from wearing bodysuit. The questions whether these suits improve performance and should they be allowed in competition are still being asked. The first aim of the study was to determine the influence of swimming suit (FS) on 50 m crawl overall time. Furthermore, possible differences of different segments of the race as well as their impact on total time for two different conditions were also examined. Fifteen male national and international level swimmers completed two trials of 50 m-crawl swimming in regular suit and swimming body suit. Block-off time, Start time, Turn time, Split time, Race time and number of strokes per 50 m were recorded. The second part of the study analysed the differences in fatigue parameters (heart rate, blood lactate concentrations, and number of strokes) in 400 m crawl constant pace test. The results show that the FS suit appears to enhance performance on 50 m crawls. Furthermore turn time, split time and race time were significantly faster while swimming wearing FS. Most of the difference (0.31 s) was gained after first 25 m and turn had been completed. In this research swimming body suit improved performance by 1.6% (0.41 s). It appears that the suit is more beneficial for start and turn (streamlining and kicking) than for swimming the full stroke. The 400 m-crawl constant pace trial determined the differences in fatigue parameters. The post-swim blood lactate concentrations and heart rate values were significantly lower while swimming in the FS suit even though there were no differences in number of strokes. These findings suggest that the FS suit seems to reduce the level of fatigue during 400 m-crawl constant pace test.

Full text

Biology of Sport, Vol. 26 No2, 2009
.
SWIMMING BODYSUIT IN ALL-OUT AND CONSTANT-PACE TRIALS
E. Tiozzo1, G. Leko2, L. Ruzic2
1Swimming Club "Mladost", Zagreb, Croatia; 2Faculty of Kinesiology, University
of Zagreb, Croatia
Abstract. There is no doubt that many swimmers do benefit from wearing
bodysuit. The questions whether these suits improve performance and should they
be allowed in competition are still being asked. The first aim of the study was to
determine the influence of swimming suit (FS) on 50 m crawl overall time.
Furthermore, possible differences of different segments of the race as well as their
impact on total time for two different conditions were also examined. Fifteen male
national and international level swimmers completed two trials of 50 m-crawl
swimming in regular suit and swimming body suit. Block-off time, Start time,
Turn time, Split time, Race time and number of strokes per 50 m were recorded.
The second part of the study analysed the differences in fatigue parameters (heart
rate, blood lactate concentrations, and number of strokes) in 400 m crawl constant
pace test. The results show that the FS suit appears to enhance performance on 50
m crawls. Furthermore turn time, split time and race time were significantly faster
while swimming wearing FS. Most of the difference (0.31 s) was gained after first
25 m and turn had been completed. In this research swimming body suit improved
performance by 1.6% (0.41 s). It appears that the suit is more beneficial for start
and turn (streamlining and kicking) than for swimming the full stroke. The 400 m-
crawl constant pace trial determined the differences in fatigue parameters. The
post-swim blood lactate concentrations and heart rate values were significantly
lower while swimming in the FS suit even though there were no differences in
number of strokes. These findings suggest that the FS suit seems to reduce the
level of fatigue during 400 m-crawl constant pace test.
(Biol.Sport 26:149-156, 2009)
Key words: Swimming suit – Bodysuit - Swimming performance - Fatigue
Reprint request to: Lana Ruzic, MD, PhD Faculty of Kinesiology, University of Zagreb
Horvaćanski zavoj 15, 10000 Zagreb, Croatia
Tel: ++385 98 380 753; Fax: 00385 1 3091 991; E-mail: lana.ruzic@kif,hr
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E. Tiozzo et al.
Biol.Sport 26(2), 2009
150
Introduction
The questions whether the swimming suits improve performance and should
they be allowed in competition are still being asked [7] Furthermore, the question
whether the long suit represents a serious threat to competitive swimming has also
been raised [6]. Even though the suits are widespread, there is a considerable lack
of studies dealing with its influence on speed or fatigue. Only a couple of
references could be find in major sport-science journals, dealing mostly with
biomechanical problems of swimming with or without a swimming suit.
After many years of research the manufacturer developed the swimming body
suit with material designed to reduce resistance. The suit mimics shark's skin. At
the Sidney 2000 Games 83% of all medals were won by swimmers wearing the
swimsuit. The swimming body suits were first introduced at the FINA World
Swimming Championship (Athena, March, 2000). To date over 60 swimmers
wearing swimming body suit have broken world records. Manufacturers claim that
the suit reduces friction drag and that the body slips through water more smoothly.
The suit appears to reduce muscle vibration thus increasing productivity from
muscles. According to the manufacturer, the suit reduces resistance by 7% and
improve results by 3% Some test in flumes have shown that passive drag can be
reduced as much as 10% in some swimming positions when wearing the full-body
swimsuit.. The benefits decrease as the swimmers perform the flutter kick and full
stroke [1]. Scientists still dwell whether the suit has beneficial effect on buoyancy.
The manufacturer claims that the suit is neutrally buoyant [8]. A study of
underwater weight of swimmers when wearing bodysuit indicated also that the
swimsuit did not help buoyancy [1] but swimmers claim that the suit helps their
legs be higher in the water. Distance swimmers, on the other hand, reported that the
suit feel buoyant for the first half of the race but after that they begin to feel
"dragged down" by the suit.
Drag reduction and result improvement issue:A basic problem with researching
the effects of bodysuits on swimming performance is that the testing itself cannot
be done in competitive environment. Those made in flume may not be good
indicators for establishing the real effect of swimming body suit suits.
Method used by Toussaint et al. with MAD system [9] is considered to yield
very good estimation of active drag. In their research a non-significant reduction in
drag of 2% (P=0.31) was found. On the other side the manufacturer claims [8] that
swimming body suit reduces passive drag by 7% and improves results by 3%.
There have been several researches where test conclusions were based not on
drag reductions but on swimming speed. Swimmers would conduct a practical test
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Swimming bodysuit in all-out and constant pace tests
Biol.Sport 26(2), 2009
151
in regular and traditional suit. The main problem of these researches is that
swimmers were not shaven when wearing regular suits. Also a regular suit can
increase drag resistance if stretched and loosen. Some coaches estimate a
significant advantage of bodysuit on underwater kicking and above-water
swimming in crawl stroke and butterfly; no advantage for backstroke and negative
effects on breaststroke. An international level backstroker and butterfly specialist
compared full bodysuit and regular suit and it was found that swimming velocity
was higher when wearing the bodysuit [8]. The total work performed comprises
also the work needed to overcome hydrodynamic resistance which can be
calculated from measures of active drag. Since the drag contributes to fatigue [10],
we might conclude that minimizing the resistance and the drag, the parameters of
fatigue might also be reduced
The aim of the study was to test the influence of swimming body suit in two
different conditions. First, we wanted to determine the influence of bodysuit on the
50 m crawl overall time and to determine whether particular parts of the race
significantly contribute to different total time while swimming in the briefs and in
the swimsuit. In the second test our objective was to determine the influence of
swimming body suit on physiological parameters of fatigue while performing 400
m constant velocity test
Materials and Methods
The sample comprised 15 male swimmers of national and international level,
mean age 18.3±2.7. The subjects were tested at the end of the physical conditioning
phase of the season. Measurements were performed in two separate weeks. The
50m and 400m distances were selected because 50 m represents speed test and
400m crawl represents appropriate distance to test the fatigue.
Day
1
Day
2
Day
3
Day
4
Day
5
Day
6
Day
7
Day
8
Day
9
Day
10
Day
11
50 m
briefs
50 m
suit
HRb LAb
400 m
briefs
HRa, LAa
HRb, LAb
400 m
suit
HRa, LAa
Fig. 1
Study protocol (HR- heart rate., LA- lactate; b- before test, a- after test)
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E. Tiozzo et al.
Biol.Sport 26(2), 2009
152
Part 1. All-out 50 m test: During the first week the subjects completed the 50 m
all out tests. First swim was performed in regular suit and second, 72 h later, in the
swimming body suit.
Six variables were measured to test the influence of swimming body suit on
speed:
 Block-off time
 Start time (15 m)
 Turn time (7.5-7.5)
 Split time (25 m)
 Race time (50 m)
 Number of strokes per 50 m
Part 2. Constant pace 400 m test: In the following week, the 400m constant
pace tests were performed. The pace lights were placed at the bottom of the pool to
dictate the pace set for each swimmer individually. Swimmers completed both 400
at the same pace (10 seconds of their personal best time). Five variables were
measured to test the influence of swimming body suit on endurance:
– Heart rate, before the test (HRb)
– Heart rate, after the test (HRa)
– Blood lactate (mmol/l), before the test (LAb)
– Blood lactate (mmol/l), after the test (LAa)
– Average number of strokes per 50 m (N of Str.)
Heart rate and blood lactate before the test were measured in order to exclude
any differences in fatigue parameters at the start of both tests.
Data were analysed by means of descriptive statistics, Student t-.test for
independent samples and multiple regression analysis.
Results
PART 1: All-out 50 m test: Descriptive statistics and Student-t-test were used to
compare the data obtained in two trials, with and without Fast-Skin swimming suit
(Table 1).
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Swimming bodysuit in all-out and constant pace tests
Biol.Sport 26(2), 2009
153
Table 1
Means, SD and P level of significance between two trials
Regular Suit
Body Suit
P values
Mean
SD
Mean
SD
Block-off time (s)
0.76
0.54
0.78
0.50
0.135
Start time (s)
6.34
0.36
6.29
0.36
0.287
Turn time (s)
7.44
0.39
7.33
0.44
0.023*
Split time –25 m (s)
12.34
0.65
12.14
0.66
0.0001*
Race time –50 m (s)
25.53
1.29
25.12
1.30
0.0003*
N of strokes
37.5
3.38
37.46
3.13
0.843
*Marked values significant on level P<0.05
Multiple regression analysis was used in order to determine the influence of
particular part of the race on total race time while swimming in regular and
swimming body suit (Table 2).
Table 2
Regression summary (influence of particular part of the race on total race time
while swimming in regular and swimming body suit)
Regular Suit
Bodysuit Suit
BETA
P-level
BETA
P-level
Block-off time
0.08
0.083
-0.06
0.253
Start time
-0.12
0.531
0.18
0.384
Turn time
0.18
0.264
0.57
0.021*
Split time (25m)
0.96
0.003*
0.18
0.465
Num. of strokes
0.05
0.144
0.04
0.202
*Marked values significant on level P<0.05
The first part of the race (Split time at 25 m) had the highest influence on the
overall 50 m time while swimming in the regular suit which can be concluded by
analysing individual variables when swimming in regular suit. The turn time was
the most significant variable in predicting the race time while swimming in the
swimming body suit (Table 2).
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E. Tiozzo et al.
Biol.Sport 26(2), 2009
154
PART 2. Constant pace 400 m test: Table 3 illustrates the values of mean, SD
and (non)-significant differences between the variables in two tests. Although the
heart rate before the test was higher when swimmers had their suits it was not
statistically significant and could be explained by the physical effort caused by
putting the suits on. However,, the post-swim results show that swimmers had
significantly lower heart rate after the test was completed in the suit. The blood
lactate after the test when wearing the suit was also significantly lower. No
significant difference was determined for the average number of strokes (Table 3).
Table 3
Means, SD and p values for lactate (LA), heart rate (HR) and number of strokes per
50/m
Regular Suit
Fastkin Suit
Mean
SD
Mean
SD
P values
HR before 400m
85
11.74
93
19.54
0.292
HR after 400m
154
13.10
143
12.32
0.021*
LA before 400m
1.81
0.64
1.70
0.29
0.661
LA after 400m
8.20
2.37
6.42
2.41
0.002*
N of strokes
32.2
4.52
30.4
3.83
0.005*
Discussion
The bodysuit appears to enhance performance in 50 m crawls. The results
indicate that turn time, split time and race time were significantly faster in the
second swim. Swimmers performed faster turn, 25m and 50m by 0,11 sec, 0,20
sec, and 0,41 sec respectively when wearing swimming body suit. Most of the
difference (0.31 s) originated from first 25m and the turn. Although the block off
time in the body. Further analysis revealed that only one swimmer was slower
while wearing the suit. Altogether, swimming body suit improved performance by
1.6 % (0.41 s). Additionally, we confirmed some previous findings that swimming
body suit improves performance more through the improvement of the diving
phase meaning during the turns and less during the swimming phase [2,9]. It
appears that the suit is more beneficial for start and turn (streamlining and kicking)
than for swimming the full stroke.
The second part of the study focused on the parameters representing fatigue A
limited number of studies, were focused on velocity during all-out tests, and to our
knowledge, only one study [5] examined the effect of the suit at submaximal
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Swimming bodysuit in all-out and constant pace tests
Biol.Sport 26(2), 2009
155
swimming performance. In our study, lower post-trial lactate values are in
contradiction to the previously published paper by Roberts et al. [5]. In that study
the better results were accompanied by increase in oxygen consumption as well as
the increase in blood lactate concentration. The difference between these two
studies might originate from the fact that the constant-pace velocity was higher in
our study because it was set in a way the swimmer would complete 400 m in 10 s
off their best performance. Also, the distance was twice as large (400 m vs. 183 m)
so the higher lactate concentrations were achieved altogether. Heart rate values
were in concordance to the blood lactate values meaning the lower values
measured after swimming in FS suit. Additional analysis showed that swimmers
had lower and constant stroke rate during the entire race when wearing the leg suit
(first 200 they averaged 30.4 strokes per 50 meters and in second 200 they had 31.8
strokes). When swimming in regular suit they applied on average 31.3 strokes in
the first half of the test, and their stroke rate deteriorated in the second half (34.4).
This would be contrary to the beliefs that the suit becomes "drag suit" after 200 m.
because the fabric absorbs the water.
According to the results in both tests the bodysuit might have an influence on
buoyancy. In the 50 m crawl trial; the most of the difference in speed was gained
during the diving and gliding phase (most notably during start and turn, ) and no
difference was observed while swimming Moreover, in the second half of 400 m
trial, when we usually expect higher front resistance (caused by fatigue and sinking
legs) [4], the subjects swimming in bodysuit sustained the same stroke frequency as
in the first 200m with lower lactate values, which was not observed while wearing
regular suit.
The results of this study could point to the fact that swimming body suit
appeared to have beneficial effect on endurance; and it seemed that the swimmers
fatigued less in the bodysuit for having lower heart rate and blood lactate at the
same speed. Additionally the study showed that swimmers had fewer strokes in
400 m (~ 2 strokes/50 m.) and for the same result when swimming in bodysuit.
Swimmers seemed to benefit the most in second half of the 400 test for having
fewer strokes (~ 3 strokes/50 m) when wearing the swimming body suit. The
interesting fact was observed in statements that were made by the swimmers, as
they all claimed beneficial effect of the FS suit from the psychological point of
view (positive motivation) so the further investigations should include the that
component also and encompass collaboration with exercise psychologists. In
conclusion, as the obtained results are in contradiction with the results of the
similar study of Roberts et al. [5], but confirm what Mollendorf et al. [3] had
found, we think more detailed research should be performed.
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E. Tiozzo et al.
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156
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