Regular Swimming Exercise Research Articles

Effects of swimming exercise on the extinction of fear memory in rats.

We investigated the relation between swimming exercise and fear memory extinction. Rats that performed regular swimming exercise over 6 wk underwent fear conditioning. Twenty-eight days later, they were submitted to extinction tests. Swimming rats had enhanced extinction process throughout the 5 days of the extinction test compared with sedentary rats. This suggests that the swimming exercise accelerated the process of aversive memory extinction, reducing the expression of conditioned fear behavior. These results encourage further studies addressing the anxiolytic effects of exercise, with potential implications for anxiety disorders such as posttraumatic stress disorder. NEW & NOTEWORTHY We have shown that rats that performed regular swimming exercise over 6 wk had enhanced extinction process compared with sedentary animals. The swimming exercise may accelerate the process of aversive memory extinction, reducing the expression of conditioned fear behavior.

Expression Profiles of Cytochrome P450s Following Swimming Exercise in Aging Rats

Background and Objective Cytochrome P450s (CYPs) are the major drug-metabolizing enzymes responsible for the clearance of approximately 75% of all drugs in clinical use. Drug clearance may be reduced with aging, resulting in increased drug toxicity in the elderly. Here, we evaluated changes in CYP expression following exercise in an aging rat model. Materials and Methods Sixteen male Sprague-Dawley rats were grouped into control (n=5), short-term exercise (SE) (n=4), and long-term exercise (LE) (n=7) groups and changes in CYPs and nuclear receptors (NRs) were measured with aging. Results CYP2C22, CYP3A1, and CYP2C11 mRNAs were upregulated, whereas CYP26B1 was downregulated in the SE and LE groups compared with the control group. Moreover, mRNA levels of the NRs, constitutive androstane receptor, retinoid X receptor α, peroxisome proliferator-activated receptor, and pregnane X receptor, were significantly increased in the LE group compared with those in the control group. As an indicator of more long-term changes, protein levels of CYP2C11, CYP2B, CYP1A, CYP2C, and CYP2C22 were significantly upregulated in the LE group compared with the control group. Overall, our data show that CYP and NR expression increased in rats with forced long-term exercise during aging. Conclusion Therefore, we propose that regular swimming exercise may increase CYP levels, resulting in enhanced drug clearance and thereby reducing age-related drug toxicity in elderly individuals.

Swimming exercise attenuates psychological dependence and voluntary methamphetamine consumption in methamphetamine withdrawn rats.

This study evaluated the effect of swimming exercise during spontaneous methamphetamine (METH) withdrawal on the anxiety, depression, obsessive-compulsive disorder (OCD) and voluntary METH consumption in METH-dependent rats. Male Wistar rats were repeatedly administered with bi-daily doses of METH (2 mg/kg, subcutaneous) over a period of 14 days. Exercised rats were submitted to swimming sessions (45 min/day, five days per week, for 14 days) during spontaneous METH-withdrawal. Then, all animals were tested for the assessment of anxiety by using the elevated plus-maze (EPM), the grooming behaviors (OCD), and depression using forced swimming test (FST) and voluntary METH consumption using a two-bottle choice (TBC) paradigm for the assessment of craving. The results showed that the swimmer METH-withdrawn rats exhibited an increase in EPM open arm time and entries and a reduction of immobility and grooming behaviors compared with the sedentary METH groups. Also, voluntary METH consumption was less in the swimmer METH-withdrawn rats than the sedentary METH groups throughout 5-8 days. This study showed that regular swimming exercise reduced voluntary METH consumption in animal models of craving by reducing anxiety, OCD, and depression in the METH-withdrawn rats. Thus, physical training may be ameliorating some of the withdrawal behavioral consequences of METH.

Improved Function and Reduced Pain after Swimming and Cycling Training in Patients with Osteoarthritis.

Arthritis and its associated joint pain act as significant barriers for adults attempting to perform land-based physical activity. Swimming can be an ideal form of exercise for patients with arthritis. Yet there is no information on the efficacy of regular swimming exercise involving patients with arthritis. The effect of a swimming exercise intervention on joint pain, stiffness, and physical function was evaluated in patients with osteoarthritis (OA). Using a randomized study design, 48 sedentary middle-aged and older adults with OA underwent 3 months of either swimming or cycling exercise training. Supervised exercise training was performed for 45 min/day, 3 days/week at 60-70% heart rate reserve for 12 weeks. The Western Ontario and McMaster Universities Arthritis Index was used to measure joint pain, stiffness, and physical limitation. After the exercise interventions, there were significant reductions in joint pain, stiffness, and physical limitation accompanied by increases in quality of life in both groups (all p < 0.05). Functional capacity as assessed by maximal handgrip strength, isokinetic knee extension and flexion power (15-30% increases), and the distance covered in the 6-min walk test increased (all p < 0.05) in both exercise groups. No differences were observed in the magnitude of improvements between swimming and cycling training. Regular swimming exercise reduced joint pain and stiffness associated with OA and improved muscle strength and functional capacity in middle-aged and older adults with OA. Additionally, the benefits of swimming exercise were similar to the more frequently prescribed land-based cycling training. clinicaltrials.gov NCT01836380.

Swimming exercise ameliorates neurocognitive impairment induced by neonatal exposure to isoflurane and enhances hippocampal histone acetylation in mice

Isoflurane-induced neurocognitive impairment in the developing rodent brain is well documented, and regular physical exercise has been demonstrated to be a viable intervention for some types of neurocognitive impairment. This study was designed to investigate the potential protective effect of swimming exercise on both neurocognitive impairment caused by repeated neonatal exposure to isoflurane and the underlying molecular mechanism. Mice received 0.75% isoflurane exposures for 4h on postnatal days 7, 8, and 9. From the third month after anesthesia, the mice were subjected to regular swimming exercise for 4weeks, followed by a contextual fear condition (CFC) trial. We found that repeated neonatal exposure to isoflurane reduced freezing behavior during CFC testing and deregulated hippocampal histone H4K12 acetylation. Conversely, mice subjected to regular swimming exercise showed enhanced hippocampal H3K9, H4K5, and H4K12 acetylation levels, increased numbers of c-Fos-positive cells 1h after CFC training, and less isoflurane-induced memory impairment. We also observed increases in histone acetylation and of cAMP-response element-binding protein (CREB)-binding protein (CBP) during the swimming exercise program. The results suggest that neonatal isoflurane exposure-induced memory impairment was associated with dysregulation of H4K12 acetylation, which may lead to less hippocampal activation following learning tasks. Swimming exercise was associated with enhanced hippocampal histone acetylation and CBP expression. Exercise most likely ameliorated isoflurane-induced memory impairment by enhancing hippocampal histone acetylation and activating more neuron cells during memory formation.

The Combined Effects of Regular Swimming Exercise and Garlic Extract on the some of the Mediator Growth Factors on the Cardiac Angiogenesis and Fibrosis in aged Rats

Introduction: Aging is a major risk factor for gradual structural and functional damage to the heart and is associated with different changes in angiogenesis and cardiac fibrosis. The present study was conducted to determine the combined effect of swimming exercise and garlic extract on some of the factors mediating angiogenesis and cardiac fibrosis in old rats. Materials and Methods: A total of 35 old Wistar rats were randomly divided into a control, a saline, an aerobic exercise, a garlic and an aerobic exercise plus garlic group. The rats were given an exercise regimen of swimming 60 minutes per day and three days per week for eight weeks. The aerobic exercise and the aerobic exercise plus garlic groups were treated with 2.5 g/kg of body weight garlic extract. The preand post-intervention levels of Vascular Endothelial Growth Factor (VEGF) and Transforming Growth Factor beta 1 (TGF-β1) were measured in all the groups. The data obtained were analyzed using the one-way ANOVA at a significance level of P 0.05). Conclusion: Each of the non-medicinal interventions of either regular exercise, garlic supplementation or their combination is likely to reduce age-related changes in angiogenesis and cardiac fibrosis through the positive regulation of VEGF and the reduction of TGF-β1.

Effect of regular swimming exercise on the physical composition, strength, and blood lipid of middle-aged women.

The purpose of this study is to define the effects of regular swimming exercise on the physical composition, physical strength, and blood lipids of middle-aged women. The subjects of this study are a total of 24 middle-aged women in the swimming group and the control group, with 12 women for each group. The swimming group performed swimming exercise for 60 min every time for 3 times a week, for a total of 12 weeks. For data processing, SPSS 21.0 statistics program was used to calculate the mean and standard deviation. For the difference verification on the change in mean for each group and between the groups, paired and independent t-tests were respectively used. As a result, for physical composition, the body fat rate decreased in the swimming group. Moreover, the difference verification result showed a statistically significant difference between the groups. For physical strength, the difference verification result for each group showed that the swimming group had a statistically significant difference in flexibility and cardiovascular endurance. Moreover, the difference verification result between the groups showed a statistically significant difference only for flexibility. For blood lipids, as a result of the difference verification for each group, T-C and TG showed a significant decrease, and HDL-C, a significant increase. However, in the difference verification result between the groups, only T-C and TG showed a statistically significant difference. With these results, it is considered that regular swimming exercise is effective for improving the physical composition, physical strength, and blood lipids of middle-aged women.

Effects of Swimming and Cycling Exercise Intervention on Vascular Function in Patients With Osteoarthritis

Swimming exercise is an ideal and excellent form of exercise for patients with osteoarthritis (OA). However, there is no scientific evidence that regular swimming reduces vascular dysfunction and inflammation and elicits similar benefits compared with land-based exercises such as cycling in terms of reducing vascular dysfunction and inflammation in patients with OA. Forty-eight middle-aged and older patients with OA were randomly assigned to swimming or cycling training groups. Cycling training was included as a non-weight-bearing land-based comparison group. After 12 weeks of supervised exercise training, central arterial stiffness, as determined by carotid-femoral pulse wave velocity, and carotid artery stiffness, through simultaneous ultrasound and applanation tonometry, decreased significantly after both swimming and cycling training. Vascular endothelial function, as determined by brachial flow-mediated dilation, increased significantly after swimming but not after cycling training. Both swimming and cycling interventions reduced interleukin-6 levels, whereas no changes were observed in other inflammatory markers. In conclusion, these results indicate that regular swimming exercise can exert similar or even superior effects on vascular function and inflammatory markers compared with land-based cycling exercise in patients with OA who often has an increased risk of developing cardiovascular disease.

Sa1735 Regular Swimming Exercise Ameliorates Acetic Acid-Induced Gastric Ulcer in Rats

Sa1735 Regular Swimming Exercise Ameliorates Acetic Acid-Induced Gastric Ulcer in Rats

Swimming reduces the severity of physical and psychological dependence and voluntary morphine consumption in morphine dependent rats

Previous studies have indicated that voluntary exercise decreases the severity of the anxiogenic-like behaviors in both morphine-dependent and withdrawn rats. This study examined the effects of regular swimming exercise during the development of dependency and spontaneous morphine withdrawal on the anxiety-depression profile and voluntary morphine consumption in morphine dependent rats. The rats were chronically treated with bi-daily doses (10mg/kg, at 12h intervals) of morphine over a period of 14 days. The exercising rats were allowed to swim (45min/d, five days per a week, for 14 or 21 days) during the development of morphine dependence and withdrawal. Then, rats were tested for the severity of morphine dependence, the elevated plus-maze (EPM), sucrose preference test (SPT) and voluntary morphine consumption using a two-bottle choice paradigm in animal models of craving. The results showed that withdrawal signs were decreased in swimmer morphine dependent rats than sedentary rats (P<0.05). Also, the swimmer morphine-dependent and withdrawn rats exhibited an increase in EPM open arm time and entries (P<0.05), higher levels of sucrose preference (P<0.001) than sedentary rats. Voluntary consumption of oral morphine was less in the swimmer morphine-withdrawn rats than the sedentary groups during four periods of the intake of drug (P<0.01). We conclude that regular swimming exercise reduces the severity of morphine dependence and voluntary morphine consumption with reducing anxiety and depression in morphine-dependent and withdrawn rats. Thus, swimming exercise may be a potential method to ameliorate some of the deleterious behavioral consequences of morphine dependence.

Swimming exercise stimulates neuro-genesis in the subventricular zone via increase in synapsin I and nerve growth factor levels.

In this study, we investigated the effects of 8-weeks of swimming exercise on neurogenesis in the subventricular zone (SVZ) and on the levels of nerve growth factor (NGF) and synapsin I protein in the olfactory bulb (OB) of adult rats at a series of relevant time points (2 days, 1 week, 2 weeks, 4 weeks, 3 months, and 6 months). Ninety-six male Sprague Dawley rats were divided into 2 groups: (1) a control group (COG; n = 48, n = 8 for each time point) and (2) a swimming exercise group (SEG; total n = 48; n = 8 for each time point). SEG performed swimming exercise for 5 days per week over a period of 8 weeks. We found that the number of 5-bromo-2’-deoxyuridine-5’-monophosphate (BrdU)- and doublecortin (DCX)-positive cells was significantly higher in SEG than in COG at all time points (Day 2, Week 1, Week 2, Week 4, Month 3, and Month 6; p < 0.001). Furthermore, NGF and synapsin I protein levels were significantly higher in SEG on Day 2, and Weeks 1, 2, and 4 than in COG (p < 0.05 for each time point). Our findings suggest that regular swimming exercise in adult rats increases neurogenesis, neuronal survival, and neuronal maintenance in the SVZ; furthermore, swimming exercise increases the levels of NGF and synapsin I in the OB.

The role of exercise training on lipoprotein profiles in adolescent males.

BackgroundMajor cardiovascular disorders are being recognized earlier in life. In this study we examined the effects of swimming and soccer training on male adolescent lipid-lipoprotein profiles relative to a maturity matched control group to determine the effects of these exercises on specific cardiovascular risk and anti-risk factors.MethodsForty five adolescent males (11.81 ± 1.38 yr) including swimmers (SW), soccer players (SO), and non-athlete, physically active individuals as controls (C), participated in this study. Training groups completed 12-wk exercise programs on three non-consecutive days per week. Plasma low-density lipoprotein (LDL), very low density lipoprotein (VLDL), high density lipoprotein (HDL), apolipoprotein A-I (apoA-I), apolipoprotein B (apoB), total cholesterol (TC), and triglyceride (TG) levels were measured in control, pre-training, during-training, and post-training.ResultsIn response to the 12-wk training period, the SO group demonstrated a decrease in the mean LDL level compared to the SW and C (SW: 0.15%; SO: −9.51%; C: 19.59%; p < 0.001) groups. There was an increase in both the SW and SO groups vs. the control in mean HDL (SW: 5.66%; SO: 3.07%; C: −7.21%; p < 0.05) and apoA-I (SW: 3.86%; SO: 5.48%; C: −1.01%; p < 0.05). ApoB was considerably lower in the training groups vs. control (SW: −9.52%; SO: −13.87%; C: 21.09%; p < 0.05). ApoA-I/apoB ratio was significantly higher in training groups vs. control (SW: 16.74%; SO: 23.71%; C: −17.35%; p < 0.001). There were no significant differences between groups for other factors.ConclusionsThe favorable alterations in LDL, HDL, apoA-I, and apoB observed in the training groups suggest that both regular swimming or soccer exercise can potentially mitigate cardiovascular risk in adolescent males.

Regular swimming exercise performed either before or after the induction of renovascular hypertension alleviates oxidative renal injury in rats

Epidemiological studies have shown that regular exercise and increased aerobic fitness are associated with a decrease in allcause mortality and morbidity, including diseases related with high blood pressure. However, whether exercise has an antiinflammatory impact on the pathogenesis of hypertension was not elucidated yet. In the present study, to investigate the potential protective and therapeutic effects of exercise training (swimming for 30 min/day, 5 days/week for 9 weeks) on renovascular hypertension (RVH) 10-week-old male Wistar albino rats were divided into 4 groups as sham-operated sedentary control group, sedentary group with RVH (2-Kidney, 1-Clip Goldblatt) and two exercised RVH groups, which had 9-week training either before the surgery or after the surgery. Systolic blood pressures (SBP) were measured by the tail-cuff method on a weekly basis and at the end of 12 weeks, rats were decapitated to obtain kidneys. SBP were significantly higher in the sedentary RVH group than the control group, whereas in the trained RVH group measurements were not different than those of the control animals. In the renal tissues of the sedentary RVH group, malondialdehyde and myeloperoxidase levels were increased with a concomitant decrease in glutathione levels, while in the trained RVH group the levels were not different than those of the control group. Moreover, in the trained RVH group, superoxide dismutase and catalase levels measured as antioxidant parameters, were also significantly increased as compared with those of the sedentary RVH group. Current results demonstrate that regular moderate training controls high blood pressure in RVH, while RVH-induced oxidative damage in renal tissue is ameliorated through the modulation of oxidant-antioxidant balance. Exercise training does not only improve the circulatory functions, but it also initiates an anti-inflammatory process to defend against the angiotensin-II-induced renal injury. Keywords: Exercise, hypertension, kidney, oxidative stress

Regular swimming exercise performed either before or after the induction of renovascular hypertension alleviates oxidative renal injury in rats

Regular swimming exercise performed either before or after the induction of renovascular hypertension alleviates oxidative renal injury in rats

Swimming exercise ameliorates depression-like behavior in chronically stressed rats: Relevant to proinflammatory cytokines and IDO activation

Chronic stress is involved in development of depression and causes immune alterations. Indoleamine-2,3-dioxygenase (IDO) plays a pivotal role in mediating the depression-like behaviors in response to immune activation. Physical exercise has been shown to reduce the stress impairment and ameliorate depressive symptoms. The objectives of present study were to confirm that chronic unpredictable mild stress (CUMS) induces depression-like behavior and inflammatory responses within the brain, and then investigate whether swimming exercise alleviates the depression-like behaviors induced by CUMS through proinflammatory cytokine-induced alteration of IDO in brain. It has been found that CUMS exposure induced depression-like behavior, increased serum corticosterone (CORT) level, decreased 5-HT level, increased IFN-γ and TNF-α levels and elevated IDO activity in prefrontal cortex. Moreover, the level of 5-HT was inversely correlated with IDO level. Regular swimming exercise ameliorated depressive symptoms induced by CUMS. The exercise reduced serum CORT level, increased 5-HT level as well as decreased levels of IFN-γ, TNF-α and IDO in prefrontal cortex in CUMS rats. These findings suggested that CUMS activate HPA axis and induce immune activation, which may stimulate IDO activity, leading to the reduction of 5-HT level in brain, thereby resulting in depression. Swimming exercise may inhibit activation of inflammation/IDO pathways induced by CUMS, thereby ameliorating depression.

Adaptation of Common Carp (Cyprinus carpio L.) to Regular Swimming Exercise I. Muscle Phospholipid Fatty Acid Composition and Lipid Peroxide Status

This study aimed to analyse whether regular swimming exercise affects skeletal muscle membrane lipid composition of fi sh. Common carps (Cyprinus carpio L., n=2x12 control vs. trained) were exercised 30 minutes/day in an artifi cial water fl ow at 0.6 m/s standard velocity. After 35 days fast-twitch type muscle samples were taken and phospholipid Fatty Acid (FA) composition was determined with column chromatography and subsequent gas chromatography. Training signifi cantly decreased the proportion of myristic (C14:0), margaric (C17:0) and arachidonic (C20:4 n6) acids and the total n6 FA proportion, while increased the proportion of behenic acid (C22:0). The fi llet malondialdehyde content (indicative of the in vivo lipid peroxidation) decreased signifi cantly in the trained group. These novel results on carp are mostly consonant with those gained so far only in homeothermic vertebrates.

Adaptation of Common Carp (Cyprinus carpio L.) to Regular Swimming Exercise II. Metabolism

Altogether 24 (12 control and 12 treated) growing (initial bodyweight: 50.4 ± 20.1 g) common carps (Cyprinus carpio L.) were subjected to a regular training protocol for 35 days, with daily 30 min strenuous exercise bouts aiming to describe blood serum clinicochemical alterations. Samples were taken 4 times (0 as control and 3 time points during training, every 9th day) from all fi sh. In the nitrogenous serum compounds the training protocol increased albumin and oxidized glutathione concentration at time point 3, while neither total protein, nor creatinine reacted to swimming. From the lipid metabolites triacylglycerol provided higher values at time point 3. Total and HDL cholesterol concentrations were unaltered, meanwhile the HDL percentage in the total cholesterol fraction provided an age-associated increase and a signifi cantly lower fi nal value in the trained group. Within enzymes aspartate and Alanine Aminotransferase (AST and ALT) provided markedly higher activity values at time point 3. Gamma-GT, pseudo cholinesterase, alkaline phosphatase and lactate dehydrogenase (LDH) showed no signifi cant changes induced by regular swimming. In the serum ions training exerted temporary hypokalemic and hypocalcemic effect (time point 2), while sodium, inorganic phosphate and magnesium were unaffected by exercise. Both groups showed an age-associated increase in the serum sodium concentrations. It was assumed that even longer term regular submaximal, but exhaustive exercise exerts only mild effect on the substrate metabolism of carp, a slowly swimming (with burst-like movements) benthic feeder.

The effects of swimming exercise on recognition memory for objects and conditioned fear in rats

Experiments conducted in animals have repeatedly demonstrated the ability of exercise to enhance cognitive function. This study examines the effects of chronic swimming exercise on non-spatial memory in adult rats after 12 weeks of swimming exercise in object recognition and elevated T-maze tests. In the object recognition test, repeated measures analysis of variance revealed a group effect (F1,42 = 26,093; p < 0.001), control rats had lower discrimination ratios than the exercise group. However, the swimming exercise did not affect the performance of inhibitory avoidance and escapes, when memory was tested in elevated T-maze. Analysis of variance showed a significant reduction in inhibitory avoidance 24h after the first training (F1,42 = 14,552; p < 0.001). Results indicated that regular swimming exercise significantly increased non-spatial memory in object recognition behavior, but did not affect the performance of inhibitory avoidance and escape on elevated T-maze test in adult rats. These findings suggest that the perirhinal cortex plays a role in memory consolidation and storage in addition to that of the amygdala, which could be regarded as the center of a second memory system, separate from those governed by the perirhinal cortex.

Sonographic appearance of nontraumatic tear of flexor carpi radialis muscle—a case report

We present an unusual case of a man with a nontraumatic tear of the flexor carpi radialis muscle after a regular swimming exercise, without known precipitation factors. The muscle tear was diagnosed by ultrasonography, which showed a cystic mass with increased peripheral vascularity, and was confirmed by magnetic resonance imaging. After conservative treatment, follow-up ultrasonography showed resolution of the hematoma. The patient was able to continue swimming without pain or limitation of function.

Effects of Swimming Training on Blood Pressure and Vascular Function in Adults >50 Years of Age

Swimming is ideal for older adults because it includes minimum weight-bearing stress and decreased heat load. However, there is very little information available concerning the effects of regular swimming exercise on vascular risks. We determined if regular swimming exercise would decrease arterial blood pressure (BP) and improve vascular function. Forty-three otherwise healthy adults >50 years old (60 ± 2) with prehypertension or stage 1 hypertension and not on any medication were randomly assigned to 12 weeks of swimming exercise or attention time controls. Before the intervention period there were no significant differences in any of the variables between groups. Body mass, adiposity, and plasma concentrations of glucose and cholesterol did not change in either group throughout the intervention period. Casual systolic BP decreased significantly from 131 ± 3 to 122 ± 4 mm Hg in the swimming training group. Significant decreases in systolic BP were also observed in ambulatory (daytime) and central (carotid) BP measurements. Swimming exercise produced a 21% increase in carotid artery compliance (p <0.05). Flow-mediated dilation and cardiovagal baroreflex sensitivity improved after the swim training program (p <0.05). There were no significant changes in any measurements in the control group that performed gentle relaxation exercises. In conclusion, swimming exercise elicits hypotensive effects and improvements in vascular function in previously sedentary older adults.