The Effect of Cool Down Laps on Lactate Recovery Rates In Male Water Polo
Players
Niku Borujerdpur, Nathan Nguyen and Kristina Nikkhah
Department of Biological Sciences
Saddleback College
Mission Viejo, CA, 92692
The sport of water polo requires multiple bouts of high-intensity exercise, leading to
elevated blood lactate. Clearance of lactate from the blood can occur either through
oxidation within the muscle it is produced from or by diffusion into the blood
stream. This study tested the hypothesis that lactate is removed more rapidly after
swimming a cool down lap. Seven male water polo players from Saddleback College
were used for this experiment, based on similar training and physical shape.
Subjects swam a 500 yard warm-up followed by a 100 yard sprint. lactate readings
were taken before and after recovery periods. A one-tail, paired t-test was used to
evaluate the difference in recovery with and without a cool down. A one tailed,
paired t-test revealed that the speed of lactate recovery after swimming a cool down
lap is significantly greater than not cooling down (p=0.000446). The average rate of
recovery with out a cool down was greater than the average rate of recovery with a
cool down. There is significant evidence to support the claim active cool down
during recovery is helpful in the removal of blood lactate produced during high
intensity exercise.
Introduction
Current research on the study of lactate metabolism suggest that the lactate levels
in the bloodstream after intense exercise provides information not only about changes in
glycolysis (Medbo1993), but also anaerobic work capacity (Fujitsuka et al. 1982). What
was once considered to be a useless by-product resulting from a lack of oxygen in
contracting skeletal muscles, the glycolitic product, lactate is formed. Lactate provides
energy to muscles by breaking down glucose without the need for oxygen (Brooks1980).
During exercises at any intensity, lactic acid is constantly being produced. Fortunately,
our bodies continuously recycle lactate, burning it as source of energy. As intensity
increases, lactate production also increases. The lactate threshold is the point during
exercise of increasing intensity at which lactic acid builds up in the blood stream faster
than the body can remove it (Asselin et al., 2006). The majority (75%+) of the lactate
produced during constant exercise is removed by oxidation with only ~20% being
converted to glucose (Brooks,1986).
The role of anaerobic metabolism in the supply of energy, as represented by
lactate dynamics, deserves further clarification. By comparing the lactate threshold to the
rate of recovery, the experiment to be performed will develop a better understanding of
how the lactate threshold is affected by the body’s ability to metabolize lactic acid. It is
hypothesized that there will be a significant relationship between the lactate threshold and
rate of recovery. Research into this area is likely to provide novel insight into the mode of
action of the relationship between the recovery rate to the lactate threshold during
exercise. Further research can also help produce biochemical adaptations that improve the
clearance and tolerance to lactate buildup so the muscles can fire more strongly and for a
longer duration during vigorous exercise (Cerretelli et al., 1999).
Material and Methods
Seven male water polo players from Saddleback College volunteered to participate in an
experiment to determine if swimming a cool-down lap after intense exercise is beneficial
to their lactate recovery rate. The test subject’s age ranged from 18 to 21 years of age.
Also, all participates were trained under the same regiment, that is, they have all been
training together under the same physical requirements. Consequently, their data should
all be quite similar thereby eliminating a potential source of error—that error being
different levels of physical fitness. The participants were all tested on two separate days,
the 10th and 19th of November. They were tested for swimming without a cool-down lap
on the 10th and tested with a cool-down lap on the 19th. All testing was conducted at
Saddleback College swimming pool and the use of a Lactate Scout and 100 lactate test
strips were also provided by the Biology Department at Saddleback College. The Lactate
Scout had been calibrated before collecting the data to ensure the accuracy of the results.
To begin the testing process, the water polo players were asked to rest for fifteen
minutes then take their heart rate at resting level prior to swimming a 500 yard (457.2
meters) warm-up. After the subjects rested, their index fingers were cleaned with an
alcohol wipe, air-dried, and pricked (GAUGE) lancets to obtain a blood sample for the
Lactate Scout to read. From this reading, the baseline blood lactate levels were obtained
and the subjects started off by swimming the 500 yard warm-up. After the warm-ups
were swum, the subjects were asked to wait one minute before swimming a 100 yard.
For this sprint, the participants were asked to swim especially hard to ensure the most
lactate production. Immediately after the participants finished the all-out sprint, their
index fingers were, again, cleaned with alcohol wipes and pricked to obtain the blood
lactate levels after extreme exercise. These data were recorded in the biology notebook
that was handed out by Professor Teh. The process of collecting blood lactate samples
was repeated 3 times in 10 minute intervals, totaling to 30 minutes altogether. During the
half an hour of blood sampling, the water polo players were asked to sit still so that no
more lactate would build up in their blood. This was another precaution taken to ensure
accurate results because even the act of walking can produce an adequate amount of
lactate. Once all the data were collected, the investigators proceeded to use the
appropriate measures to calculate and interpret all the data.
Analysis begun by performing paired, one-tailed t-tests two samples for means.
These t-tests were ran using Microsoft Excel; these tests were ran multiple times to see
the correlation between lactate production and time, heart rate and time, and the average
times it took for the seven male water polo players to come back down to their baseline
blood lactate levels. Statistical analysis was also used in the calculation for the means of
lactate production, recovery time, and heart rates. Statistical analysis was also used to
find the standard error mean in order to include the S.E.M. bars on the figures. Three
figures in total were produced using the interpreted data from these various tests. One
figure was used to correlate lactate production versus time, another was used to correlate
lactate recovery versus time, and the last was used to see what the relationship between
heart rate and time was.
Results
There was a difference (p= 0.00045 one-tail, paired t-test) with mean value of 24.6 ±
2.06 mM for without cool down and 10.6 ± 1.57 mM with cool down (± SEM, n=7) the
time it took to come back down to a baseline blood lactate level. When swimming a cool
down as opposed to not swimming a cool down. (Figure 1) Next, the lactate levels were
graphed against time (min) and we obtained a p-value of 0.38 using a one-tail, paired ttest which shows that there was no significant difference (Figure 2). The mean heart rate
was 94.8 beats per minute (BPM) without cool down and 96.7(BPM) with a cool down,
this could be correlated with their lactate by saying that the higher the heart the more
blood lactate will be produced. The harder you swim, the higher your heart rate and
therefore, the more blood lactate you will produce. (Figure 3).
Figure 1 - This bar graph shows the average time it took for seven male water polo
players to recover from their time at peak blood lactate levels, back down to their
baseline blood lactate levels. A one-tailed, paired t-test was calculated on the average
recovery times of each participant: p-value=4.46X10-4; therefore, we can state that there
was a significant difference in the lactate recovery time after swimming a cool down lap
or not swimming a cool down lap after intense exercise.
Figure 2 – This graph shows the relationship between the mean lactate levels in
accordance to the time at which the blood sample was taken in seven male water polo
players. A one tailed paired t-test revealed that there is no significant difference of
lactate levels at different times (p=0.38)., we can deduce that there is no significant
difference between the amount of lactate produced and swimming or not swimming a
cool down lap after intense exercise.
Figure 3 – This line graph shows the correlation of the participant’s heart rates to the
respective time interval at which blood samples were drawn from them. It is
hypothesized that the higher the heart rate is, the more lactate will build up in one’s
blood. With the swimming of a cool-down lap after intense exercise, the blood lactate
will be able to recover more quickly if one does not swim a cool-down. The mean
averages were 94.8 with out a cool down and 96.7 with a cool down, which shows that
they have been working hard.
Discussion
The results support the hypothesis that a low intensity cool down during recovery will
remove lactate more rapidly than a cool down without a recovery. This study indicates
that no significant correlation exists between recovery rate due to a difference in cool
down routine.
Cool down following 500 yard warm up and a 100 yard sprint resulted in greater lactate
disappearance than without a cool down (Fig. 1). Asselin, of Medicine & Science in
Sports and Exercise found that active recovery immediately after the strenuous exercise
encourages recovery and reduces muscle lactate levels faster than complete rest (Asselin
et al., 2006).
Heart rate correlates with blood lactate produced because the more strenuous force put
into the swim results in more lactate produced (Fig 2). The intensity of the cool down
affects how quickly lactate is removed (Cerretelli et al., 1999). Additional lactate may be
produced if the intensity is too light. At too low of an intensity, lactate may not create
enough circulation to remove lactate faster than no cool down would (Medbo,1993).The
average rate of recovery with out a cool down was greater than the average rate of
recovery with a cool down (Fig 3).
The removal of lactate takes approximately one hour but this can be increased by
undergoing a cool down that ensures a fast and continuous supply of oxygen to the
muscles (Medbo,1993). This study suggests that coaches should consider incorporating a
recovery cool down during hard training sessions.
Acknowledgements
Special thanks to Professor Teh for providing us with the knowledge to take on
this project. Also thanks to Saddleback College swimmers for taking place in our
experiment.
Literature Cited
Asselin, E. M. Bunker, M. P. Chason, J. D. Littlefield, N. Scott, C. (2006), Differences in
Oxygen uptake but equivalent energy e between a brief bout of cycling and running, Nutr
Metab (Lond) 86(3), 33-39 doi: 10.1186/1743-7075-3-1
Brooks, A. George (1980) End points of lactate and glucose metabolism after exhausting
exercise. J Appl Physiol. Dec;49(6):1057-1069
Brooks, A. George (1986) The Lactate Shuttle During Exercise and Recovery, Journal of
the American College of Sports Medicine, 18;3, p 360-368
Cerretelli, P. Ferrari, M. Grassi, B, Marconi, C. Quaresima, V. (1999) Blood lactate
accumulation and muscle deoxygenation during incremental exercise, Journal of Applied
Physiology, 87(1) 348-355 , doi: 8750-7587/99
Fujitsuka N, Yamamoto T, Ohkuwa T, Saito M, Miyamura M. Peak
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Review Form
Department of Biological Sciences
Saddleback College, Mission Viejo, CA 92692
Author (s): Niku Borujerdpur, Nathan Nguyen and Kristina Nikkhah
Title:_The effect of cool down laps on lactate recovery rates in male water polo players
Summary
Summarize the paper succinctly and dispassionately. Do not criticize here, just show that
you understood the paper.
This paper tests the hypothesis that cooling down after a swimming workout increases
lactate recovery rates. They tested this by having water polo players swim and then
testing their blood lactate at different intervals and after they completed their cool down
laps. The researchers found evidence to support their hypothesis that cooling down
increases lactate recovery rates, but they found no difference in lactate levels while
swimming with and without cool down laps.
General Comments
Generally explain the paper’s strengths and weaknesses and whether they are serious, or
important to our current state of knowledge.
Abstract should be re-written or strongly modified. The paper has a strong introduction
and materials and methods but some stuff is just stated and not explained upon so it does
not make much sense. The results are mixed with the discussion, it seems like there is
more discussion in the results section than in the discussion section. The graphs are
graphed correctly but the figure captions state data and discussion instead of explaining
the figure. The discussion section just states findings from other papers but does not
discuss anything.The paper does have a conclusion, but none of the results or conclusion
were discussed in detail providing insight as to reasons why the results turned out this
way. Over all biggest problem is organization of sentences and explanation.
Technical Criticism
Review technical issues, organization and clarity. Provide a table of typographical errors,
grammatical errors, and minor textual problems. It's not the reviewer's job to copy Edit
the paper, mark the manuscript.
This paper was a final version
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X This paper was a rough draft
No major spelling errors
In text citations
o Comma in citations which needs to be removed
Grammatical Errors
o A lot of double spaces after commas
o Words stuck together
o Lack of or addition of unnecessary periods