Running head: EFFECT OF EXERCISE ON ALCOHOL AND SLEEP
The effect of exercise in reducing sleep caused by intoxication
Silva Redigonda
Abstract
"One hundred and four mice, 52 males and 52 females, were assigned to wheel (free-access to a running wheel in their home cage) or no-wheel conditions, with body-weight balanced between the two groups. At the end of a five-week training period, all of the animals were removed from their cages injected with the same dose of alcohol. Their sensitivity to alcohol was accessed by measuring how long it took each mouse to fall asleep. The exercised mice took longer to fall into an alcohol-induced sleep and had reduced sleep duration. Exercise caused a significant decrease in body-weight of male, but not female, mice. The present results suggest that exercise training may be effective in reducing alcohol-induced sleep" (Abstract 2, assignment 3, unknown author, PSYC 2030 Introduction to Research Methods).
The Effect of Exercise in reducing sleep caused by intoxication
Exercise and alcohol consumption are factors that can affect the quality of life for many individuals in society. Exercise is typically considered to have positive health benefits and frequent and/or chronic alcohol consumption is generally associated with negative health risks. The purpose of this study is to determine how exercise can decrease the negative effects of alcohol consumption on sleep caused by intoxication.
Previous work has looked at the relationship between exercise and quality of life. One study looked at how exercise has an important role to play in reducing the rate of aging (Samorajski, Delaney & Durham, 1985). This study found that exercise helps slow down aging and helps individuals decrease their probability of developing diseases related to aging, "Regular, long-term exercise may retard the normal aging process and help prevent age-related diseases in human beings" (Samorajski et al, 1985).
Other studies have also investigated the effects of exercise but in relation to the effects of alcohol. For example, on study looked at the effects of exercise in conjunction with alcohol intoxication and found that prior exercise can reduce the effects of alcohol intoxication (Mollenauer, Bryson, Speck & Chamberlin, 1992). Another study looked at the opposite relationship and found that alcohol consumption can have a negative effect on exercise, "Alcohol use is directly linked to the rate of injury sustained in sport events and appears to evoke detrimental effects on exercise performance capacity" (El-Sayed, Ali, & El-Sayed Ali, 2005).
One study reported the effects of exercise and alcohol consumption using rats and found that, "Physical training attenuates the chronic ethanol-induced hypertension via reduction of body weight, clearance of ethanol, and augmentation of the aortic endothelial relaxation response in rats" Husain, Ortiz & Lalla, 2006). The purpose of the above mentioned study was to discuss the inconsistencies present in the literature about the benefits or risks of alcohol in relation to exercise:
There are contradictory reports about the influence of
chronic alcohol consumption on vascular responsiveness
in the presence and absence of endothelium to
vasodiators. These conflicting reports are related to
differences in dose, duration and mode of ethanol
exposure at different experimental conditions. Hence,
this study is based on established exact and controlled oral hypertensive dose and duration of ethanol in a rat model. (p. 247)
A study by Finn, Benjamin, Jones, Syapin and Alkana (1989) used mice to investigate how exposure to very cold temperatures can effect the metabolism of alcohol. The authors of this study contend that, "These results provide further evidence that body temperature during intoxication can have major effects on mortality rates in mice" (Finn et al, 1989).
The studies discussed above have articulated that an effect between alcohol and exercise exists, the relationship between these variables have important implications on quality of life, and that there is a need to study this effect under controlled conditions. This present study, therefore, has combined the existing knowledge of the relationship between the variables at hand to investigate how they can interact with sleep; in particular, sleep induced by intoxication.
Method
Subjects
104 mice were obtained from a laboratory for study purposes. There were 52 male mice and 52 female mice. The mice were randomly selected and immediately placed in their correct cages according to their condition. The male and female mice were distributed evenly across conditions so that 26 female mice and 26 male mice were assigned to the wheel condition and 26 female mice and 26 male mice were assigned to the no wheel condition. Ethical procedures were followed in the treatment of the mice.
Apparatus
Four large cages were used to house the mice. Males and females were kept in separate cages and there were separate cages for male or female mice in the wheel or no wheel conditions. The two cages that were occupied by mice in the wheel condition were equipped with a standard laboratory running wheel made by Samson Co. model number: 1458972363. The body temperature of the mice were measured by a standard rectal thermometer made by Johnsons and Johnsons model number: 4782349982. A scale made by Kilby-sons was used to measure body weight, model number: 98726389037. A syringe was used to inject the mice with alcohol and a timer was used to measure time awake and time asleep.
Procedure
As soon as the mice were brought into the laboratory, they were randomly assigned and placed in their cages. Temperature measurements were recorded for all mice prior to experimentation to make sure all mice were healthy at the start of the experiment. No abnormal temperatures were found. All the mice were subsequently weighed to record body weight prior to experimentation. Body weight measurements were compared for all mice to determine if they had been randomly selected and were equivalent in all conditions for body weight. The analysis of body weight confirmed random assignment.
After the initial measurements of the mice were collected, the mice were free to roam around their cages. Food and water were easily accessible to all the mice. For mice in the wheel condition, the amount of times the wheel was used by a given mouse was recorded in order to record amount of exercise undertaken by each mouse in this condition. All the mice in the wheel condition were found to have exercised roughly an equal amount.
After a five-week exercise regimen, all the mice in the wheel condition and in the no wheel condition were taken out of their cages and injected with 0.001 mg of alcohol. All mice were injected with the same amount of alcohol. Immediately following the injection, the mice were timed with a timer to record how long it would take them to fall asleep. Once the mice fell asleep, they were timed for how long they slept. After the mice woke up, their body weight was measured to determine whether or not their weight fluctuated as a result of the alcohol injection.
Results
Data were analyzed using descriptive statistics to check that there were no differences between the mice in either condition in regards to their temperature and body weight. Table 1 lists the respective mean body temperature and body weight for mice in either condition. There were no differences found between groups on these measures.
Data were then analyzed to determine if differences existed between groups for time it took the mice to fall asleep after they were injected with alcohol. A t-test was used to determine if any differences that were found between the groups were significant.
Ho: mtime to fall asleep for wheel group = mtime to fall asleep for no wheel group
H1: mtime to fall asleep for wheel group ¹ mtime to fall asleep for no wheel group
a = 0.05
The subjects averaged M = minutes to fall asleep in the wheel condition with SD = . Statistical analysis indicates that the time spent to fall asleep for mice in the wheel condition was significantly more than would be expected by chance, t( ) = ,p < .05.
Data were then analyzed to determine if differences existed between groups for the duration of sleeping time once the mice fell asleep. A t-test was used to determine if differences between the groups were significant.
Ho: mduration of sleeping time for wheel group = mduration of sleeping time for no wheel group
H1: mduration of sleeping time for wheel group ¹ mduration of sleeping time for no wheel group
a = 0.05
The subjects averaged M = minutes to stay asleep in the wheel condition with SD = . Statistical analysis indicates that the time spent sleeping for mice in the wheel condition was significantly less than would be expected by chance, t( ) = ,p < .05.
Data were analyzed to determine if differences existed between groups for body weight after alcohol injection. A t-test was used to determine if differences between the groups were significant.
Ho: mbody weight for wheel group = mbody weight for no wheel group
H1: mbody weight for wheel group ¹ mbody weight for no wheel group
a = 0.05
The male subjects averaged M = body weight in the wheel condition with SD = and the female subjects averaged M = body weight in the wheel condition. Statistical analysis indicates that body weight for the male subjects in the wheel condition was significantly less than would be expected by chance, t( ) = ,p < .05. The body weight change for female subjects was not significant.
The differences between groups are presented in Table 2. The differences are also displayed on Figure 1, Figure 2 and Figure 3.
Discussion
The purpose of this study was to determine whether or not exercise has a positive impact on reducing intoxication-induced sleep. Based on past studies, exercise has positive health benefits ranging from prolonged longevity (Samorajski et al, 1985) to reducing hypertension and body weight as caused by alcohol consumption (Husain et al, 2006). Based on the results of this present study, exercise helps to prolong the onset of sleep and helps to reduce intoxication-induced sleep. This claim is supported by the length of time it took mice to fall asleep and stay asleep in the two conditions. The mice who were in the wheel condition and had the opportunity to exercise daily, took longer to fall asleep after being injected with alcohol. The mice in the wheel condition also spent less time in the intoxication-induced sleep. The mice who were in the no wheel condition, however, fell asleep much faster after being injected with alcohol and stayed asleep longer as well. The differences were significant, which demonstrates that these differences were not likely due to chance.
This study supports findings from other studies, which have also found that exercise can help reduce the negative effects of intoxication (Mollenauer et al, 1992). It is unclear as to why changes in body weight occurred for males but not for females. More studies would need to be conducted to investigate this phenomenon. Another limitation of this study is that the results may not be generalizable to humans, and thus it may not be accurate to say that humans would also experience less sleep-induced intoxication if they were to follow an exercise regimen. While an experiment such as this one could not be conducted on humans for ethical reasons, it would be possible to recruit participants who self-report high consumption of alcohol and put them on an exercise regimen to determine if similar results would ensue.
References
El-Sayed, M. S., Ali, N., & El-Sayed Ali, Z. (2005). Interaction
between alcohol and exercise. Sports Medicine, 35(3), 257-
269.
Finn, D. A., Bejanian, M., Jones, B. L., Syapin, P. J., &
Alkana, R.L.(1989). Temperature affects ethanol lethality
in C57BL/6, 129, LS and SS mice. Pharmacology Biochemistry
& Behavior, 34, 375-380.
Husain, K., Ortiz, M. V., & Lalla, J. (2006). Physical training
ameliorates chronic alcohol-induced hypertension and aortic
reactivity in rats. Alcohol & Alcoholism, 41, 247-253.
Mollenauer, S., Bryson, R., Speck, C, & Chamberlin, J. R.(1992).
Effects of exercise on ethanol-induced hypothermia
and loss of righting response in C7BL/6J mice. Pharmacology
Biochemistry & Behavior, 43, 285-290.
Samorajski, T., Delaney, C., & Durham, L. (1985). Effect of
exercise on longevity, body weight, locomotor performance,
and passive-avoidance memory of C57BL/6J mice. Neurobiology
of aging, 6, 17-24.
Table 1
Means for Different Treatments
Condition
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Mean Male Mice Body Temperature
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Mean Female Mice Body Temperature
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Mean Male Mice Body Weight
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Mean Female Mice Body Weight
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Wheel
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No Wheel
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Table 2
Condition
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Mean Male time to fall asleep
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Mean Female time to fall asleep
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Mean Male time to stay asleep
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Mean female time to stay asleep
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Wheel
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No Wheel
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Figure Captions
Figure 1. Graph of amount of time to sleep per condition
Figure 2. Graph of amount of time spent sleeping per condition
Figure 3. Graph of body weight change in male mice
Time it took mice to fall asleep per condition
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Length of time mice spent sleeping per condition
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Changes in body weight for male mice per condition
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