Lactate Recovery Rates After Swimming a Cool Down Or Not Swimming a Cool Down in Male Water

LACTATE RECOVERY RATES AFTER SWIMMING A COOL DOWN OR NOT SWIMMING A COOL DOWN 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 examined the effects of swimming a cool down lap after intense exercise to see if it is beneficial to their recovery rate. 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. Our results support our hypothesis that with active recovery (p=0.000446), lactate was removed more rapidly after swimming a cool down. The average rate of recovery with out a cool down was greater than the average rate of recovery with a cool down. The present data suggests that 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 (Medbo,1993) but about 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 and provides energy to muscles by breaking down glucose without the need for oxygen (Brooks,1980). 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 bodies 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= 4.5x10-4 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 t-test which shows that there was no significant difference (Figure 2). Depending on how hard each individual was swimming, their 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. Standard error mean bars are shown, average recovery time ±S.E.M.

Figure 2 – Thisgraph 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. The use of a one tailed, paired t-test will give the specific p-value to determine whether or not there is any significant difference between lactate levels and time. From the t-test we obtained a p-value of 0.38 and therefore, 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. Standard error mean bars are shown with 95% confidence, lactate levels±S.E.M.

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

Our results support our hypothesis indicating 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).

In conclusion, an active cool down recovery suggest that coaches should consider incorporating a recovery cool down during hard training sessions. 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).

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.

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