• Journal of Community Nutrition
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• v.4 no.3
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• pp.195-201
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• 2002

The purpose of this study was to examine the effects of dietary calcium supplementation and exercise on bone mineral density and bone mineral content of growing female rats. The exercise and control group were fed a diet containing 0.5% calcium and Ca supplementation group were fed a diet containing 1.0% calcium diet. The exercise group ran on a rodent treadmill (speed of 15m/min for 30 min) three days per week during the 3-week study period. Bone mineral density (BMD) and bone mineral content (BMC) of spine and femur were determined by using dual energy x-ray absorptiometry (FIXI-mus, GE Lunar Radiation Cooperation, Madison, WI, USA). The exercise group had significantly greater (6.25%) spine BMD compared to the nonexercise group and the exercise group had but not significantly greater spine BMC (7.1%) compared to nonexercisers. Femur BMD and BMC divided by the rats final body weight appears to have a higher BMD (7.5%) and BMC (4.5%) in the exercise group, which indicates that exercise had a positive influence on femur bone mineral density and bone mineral content. The supplementation of calcium did not significantly affect spine and femoral BMC and BMD for the 3 weeks experimental period. It can be concluded that when calcium intake meets the recommended, exercise is beneficial for acquisition of spine bone mineral density in young growing female rats. (J Community Nutrition 4(3) : 195∼201, 2002)

• Journal of Community Nutrition
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• v.6 no.1
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• pp.48-54
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• 2004

The purpose of this study was to examine the effects of dietary protein and exercise on bone mineral density and bone mineral content of growing male rats. Forty male, Sprague-Dawley rats(age 21 days) were assigned to four groups that underwent 9 weeks of experimental treatment. Animals were assigned to one of two exercise treatments (treadmill running or sedentary). The exercise and nonexercise group were fed a diet containing casein or soy with rich isoflavones (3.4mg/g protein). The exercise group ran on a rodent treadmill(speed of 15m/min for 30min) three days per week during the 9-week study period. All rats were fed an experimental diet and deionized water ad libitum for 9 weeks. Total bone mineral density (BMD), total bone mineral content (BMC), total body calcium, spine BMD and BMC, and femur BMD and BMC were determined by using dual energy x-ray absorptiometry (FIXI-mus, GE Lunar Radiation Cooperation, Madison, WI, USA). The soy diet group appears to have a significantly higher total BMD/weight and total BMC/ weight, spine BMD/weight, spine BMC/weight, femur BMD/weight and femur BMC/weight compared to the casein group in nonexercise and exercise. The exercise group had significantly greater total BMD/weight and BMC/ weight, spine BMD/weight and BMC/weight, femur BMD/weight and BMC/weight compared to the nonexercise group when the protein source was casein. The exercise combined soy group had significantly greater total BMD/weight and BMC/weight, spine BMD/weight and BMC/weight, femur BMD/weight and BMC/weight, compared to the exercise combined casein group. The results indicate that exercise had a positive influence on bone mineral density and bone mineral content and soy significantly affect on bone mineral density and bone mineral content for the 9 weeks experimental period. It can be concluded that exercise combined with a soy diet is most beneficial for acquisition of spine bone mineral density in young growing male rats. This convincing evidence suggests that a change in life style such as increasing exercise and consumption of soy protein is a practical strategy for significantly reducing the incidence of osteoporosis.

• Journal of Community Nutrition
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• v.7 no.2
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• pp.93-99
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• 2005

This study investigated associations between exercise habit and bone mineral density (BMD) and bone mineral content (BMC) in postmenopausal women. The BMD and BMC of the spinal skeleton was measured by dual energy x-ray absorptiometry. Exercise and energy expenditure of physical activity were estimated by questionnaire. For exercise activities, subjects were asked to identify all exercises they have participated in. The subjects were further asked to estimate the number of years of participation, the number of weeks per year, the number of times per week, and the number of hours per time. Subjects were then categorized into exercise (more than 3 times/wk, more than 30min per session exercise (n = 47) and nonexercise group (n = 72). Results indicated that there were no significant differences in BMD and BMC when comparisons were made between subjects in exercise habit, a general exercise group and a nonexercise control group. However, when exercise subjects were divided into weight-bearing and nonweight-bearing groups, significant differences were found. These results suggest that weight-bearing exercise positively influences bone mineral density and bone mineral content in postmenopausal women. Sedentary women should be encouraged to adopt a weight-bearing exercise to maintain the health of their skeletons. Exercise interventions are practical and feasible for healthy women and should be encouraged at the earliest possible age. Our findings lend support to recommendations for physical activity and weight-bearing exercise as a means of osteoporosis prevention.

• Korean Journal of Exercise Nutrition
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• v.25 no.2
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• pp.15-19
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• 2021

[Purpose] Skeletal muscle glycogen is a determinant of endurance capacity for some athletes. Ginger is well known to possess nutritional effects, such as anti-diabetic effects. We hypothesized that ginger extract (GE) ingestion increases skeletal muscle glycogen by enhancing fat oxidation. Thus, we investigated the effect of GE ingestion on exercise capacity, skeletal muscle glycogen, and certain blood metabolites in exercised rats. [Methods] First, we evaluated the influence of GE ingestion on body weight and elevation of exercise performance in rats fed with different volumes of GE. Next, we measured the skeletal muscle glycogen content and free fatty acid (FFA) levels in GE-fed rats. Finally, we demonstrated that GE ingestion contributes to endurance capacity during intermittent exercise to exhaustion. [Results] We confirmed that GE ingestion increased exercise performance (p<0.05) and elevated the skeletal muscle glycogen content compared to the nonGE-fed (CE, control exercise) group before exercise (Soleus: p<0.01, Plantaris: p<0.01, Gastrocnemius: p<0.05). Blood FFA levels in the GE group were significantly higher than those in the CE group after exercise (p<0.05). Moreover, we demonstrated that exercise capacity was maintained in the CE group during intermittent exercise (p<0.05). [Conclusion] These findings indicate that GE ingestion increases skeletal muscle glycogen content and exercise performance through the upregulation of fat oxidation.

• Journal of Korean Biological Nursing Science
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• v.13 no.1
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• pp.1-7
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• 2011

Purpose: The purpose of this study was to compare the hypertrophic effects of low-intensity exercise on weight, myofibrillar protein content and Type I, II fiber cross-sectional area of hindlimb muscles of rats between every other day exercise and every day exercise. Methods: Adult male Sprague-Dawley rats were assigned to 1 of 3 groups: control group (C, n=6), experimental group 1 (E1, n=7) and experimental group 2 (E2, n=7). Rats in E1 group had 7 sessions (every other day) and those in E2 group had 14 sessions (every day) of exercise in which they ran on a treadmill for 30 min/day at 10 m/min. Results: Muscle weight, cross-sectional area of type I fiber and myofibrillar protein content of soleus and myofibrillar protein content of plantaris in E1 group, and myofibrillar protein content of soleus and cross-sectional area of type I fiber of plantaris in E2 group were greater than those in C group. Cross-sectional area of type I fiber of soleus of E1 group was higher than E2 group while cross-sectional area of type I fiber of plantaris of E2 group was higher than E1 group. Conclusion: Hypertrophy of hindlimb muscles occurs from every other day exercise similar to every day exercise.

• The Journal of Korean Physical Therapy
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• v.15 no.3
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• pp.189-201
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• 2003

The purpose of this study was to know the effect of aquatic-exercise on muscle atrophy which induced by steroid injection. The forty-eight Sparague-Dawley adult male rats were assigned to the 4 groups; Group I (distilled water injection), Group II (steroid injection), Group III (distilled water injection with aquatic exercise), Group IV (steroid injection with aquatic exercise). We observed their body weight, muscle relative weight, myofibrillar protein content. The results of this study were as follows; 1. Body weight was decreased rapidly on steroid injection groups in comparison with distilled water injection groups after 2 weeks (p<0.01), but that was almost recovered as before test on steroid injection group with aquatic exercise. 2. The relative weight of gastrocnemius muscles was decreased on steroid injection groups in comparison with distilled water injection groups. however, Decrease of it on steroid injection group with aquatic exercise for steroid injection group was fallen. There was very significant difference after 4 weeks (p<0.01). 3. Myofibrillar protein content of gastrocnemius muscles was decreased on steroid injection groups in comparison with distilled water injection groups. however, Decrease of it on steroid injection group with aquatic exercise for steroid injection group was fallen. There was significant difference after 4 weeks (p<0.05).

• Journal of Nutrition and Health
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• v.35 no.8
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• pp.825-833
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• 2002

The effects of dietary supplementation of Eleutherococcus senticosus, taurine and carnitine on maximal endurance exercise performance along with other related parameters were evaluated in rats that underwent aerobic exercise training for 6 weeks. Thirty-two male rats (4 weeks old) were randomly divided into 4 groups, and fed experimental diets and/or aerobic exercise trained according to the protocol: SC (sedentary control group), EC (exercise-trained control group), EE (exercise-trained Eleutherococcus senticosus-supplemented group), and EETC (exercise-trained Eleutherococcus senticosus, taurine and carnitine-supplemented group). The food efficiency ratio of EC rats was significantly lower than the value for SC rats (p < 0.01). Exercise-trained control animals (92 $\pm$ 8.8 min) could run significantly longer until exhausted on the treadmill than sedentary control rats (11 $\pm$ 0.8 min) (p < 0.001). Animals fed an Eleutherococcus senticosus-supplemented diet, and an Eleuthherococcus sonticosus, taurine and carnitine- supplemented diet while undergoing aerobic exercise training for 6 weeks exhibited, respectively, 8 and 5 minutes longer running performance until exhausted than the rats fed the control diet. The gastrocnemius muscle glycogen concentration of the rats, measured at 48 hours post maximal exercise performance test, was 43% higher in EC rats than the value for SC rats (p < 0.05), but was not different among EC, EE, and EETC rats. The mitochondrial citrate synthase activity of the soleus muscle was significantly higher in EC rats compared to the value for SC rats (p < 0.01), and showed a tendency to increase, without statistical significance, in EE or EETC rats compared to the value for EC rats. These results indicate that aerobic exercise training for 6 weeks significantly improved maximal exercise performance, muscle glycogen content along with citrate synthase activity, which are important in the energy metabolism of muscle under aerobic exercise. Dietary supplementation of Eleutherococcus senticosus in rats while undergoing aerobic exercise training improved maximal endurance exercise performance without significantly affecting muscle glycogen content and enzyme activities involved in energy metabolism during exercise. Taurine and carnitine supplementation failed to show an additive effect on maximal endurance exercise performance when consumed along with Eleutherococcus senticosus.

• Journal of Nutrition and Health
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• v.21 no.1
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• pp.23-35
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• 1988

This study was designed to find out the effects of aerobic exercise on lipid and Ca metabolism in seven healthy college women, aged 20 to 22 years. Metabolic studies were conducted before and after a 10-weeks exercise period, during which subjects participated in the planned aerobic dance program every day except Sunday. The initial mean time engaged in the exercise was 28 minutes and it was gradually increased up to 45 minutes around the middle point of the exercise period. During both of metabolic study periods, the subjects ate experimental diets which supplied about 120g of protein and 600mg of Ca daily and during the rest of the experimental period they ate their usual diets. The use of alcoholic beverages and drugs were prohibited. The results were summarized as follows. 1) The effect of exercise on lipid metabolism. (1) Mean body weight decreased significantly after exercise(p<0.01) and it did not show a significant decline in skinfold thickness and total body fat contents. (2) Serum total cholesterol level decreased significantly after exercise(p<0.05) and TG level also tended to be lower than that of pre-exercise period. Exercise did not exert any influence on the level of serum HDL-cholesterol in this study. (3) Exercise did not alter total lipid content in feces and apparent lipid absorption rate. 2) The effect of exercise on Ca and P metabolism. (1) After exercise, focal Ca excretion was slightly reduced, however, urinary Ca excretion was not significantly changed. In the results, a slight increase was shown in body Ca retention after exercise. (2) Exercise tended to increase urinary P excretion, but neither P balance nor fecal excretion was significantly changed after exercise. (3) Bone mineral content was not affected by exercise. In summary, aerobic exercise decreased total cholesterol and TG level in serum and tended to increase body Ca retention. With the results, it can be concluded that the additional physical activities beyond the normal daily life in college women might prevent some degenerative diseases-suchas atherosclerosis and osteoporosis.

• Journal of Korean Academy of Nursing
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• v.25 no.2
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• pp.193-209
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• 1995

The purpose of this study was to determine the effect of intermittent low - intensity, short duration exercise during hindlimb suspension on the mass, relative weight, myofibrillar protein content, cross-sectional area of Type I and Type II fibers and SDH activity in Type II(plantaris) muscle. To examine the effectiveness of intermittent low-intensity, short duration exercise on mass, myofibrillar protein content and fiber size, the hindlimbs of adult female Wistar rats were suspended(HS) and half of these rats walked on a treadmill for 45 min/day(9 min every 2h) at 5m /min and a 15$^{\circ}$grade (HS-EX). Plantaris wet weight was 19.67% significantly smaller(p<0.005) and relative plantaris weight was 6.25% smaller compared with those of control rats following seven days of hindlimb suspension. Plantaris wet weight and relative plantaris weight increased by 27.66%, 12.22% each through intermit-tent exercise during hindlimb suspension(p<0.005, p<0.05), moreover, plantaris wet weight and relative plantaris weight of the HS-EX rats were similar to those of control rats. Soleus wet weight and relative soleus weight decreased significantly by 31% and 22.0% in the HS rats(p<0.05). Soleus wet weight and relative soleus weight increased by 10.41%, 25.64% respectively through intermittent ex-ercise during hindlimb suspension, furthermore, soleus wet weight and relative weight of the HS-EX rats were closer to those of control rats. Myofibrillar protein content of plantaris and soleus decreased significantly by 51.49%, 59.65% each, following seven days of hindlimb suspension (p<0.005) Myofibrillar protein content of plantaris and soleus increased by 51.79%, 75.47% each with significance through intermittent exercise during hindlimb suspension(p<0.005). Myofibrillar protein content of plantaris and soleus in HS-EX rats was smaller than that of control rats. No change was observed in fiber type percentage following 1 week of hindlimb suspension or exercise during hindlimb suspension. The type I fiber cross-sectional area of both soleus and plantaris muscle was 18.72% and 41.07% lower in the HS than that of the controls (p<0.05, p<.001), that of both muscles was 6.60% and 29. 3％ greater in the HS-EX than that of the HS rats. HS plus intermittent low- intensity short duration exercise resulted in Type I fiber cross-sectional area closer to the controls. Type II fiber cross-sectional area of both plantaris and soleus muscle was 22.45% and 22.58% sl nailer in the HS than in the controls, that of both muschles in the HS-EX was 14.10%, 5.78% greater than HS. Intermittent exercise during hindlimb suspension resulted in Type I, II fiber cross-sectional area closer to the control value. There was no change in SDH activity following 1week of hindlimb suspension or exercise during hindlimb suspension in the plantaris muscle. The results suggest that intermittent low intensity short duration exercise can ameliorate Type II muscular atrophy Induced by hindlimb suspension.

• Journal of Korean Academy of Nursing
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• v.28 no.4
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• pp.893-907
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• 1998

The purpose of this study was to determine the effect of regular exercise during dexamethasone injection on the body weight, weight of hindlimb muslces, myofibrillar protein content and glutamine synthetase activity. 180-200g female Wistar rats were divided into four groups : control, exercise, dexamethasone injection (dexa), and exercise during dexamethasone injection(D+E) group. The dexa group received daily subcutaneous injection of dexamethasone at a dose of 4mg/kg body weight for 7 days. The exercise group ran on a treadmill for 60min/day(20minutes every 4 hours) at 10m/min and a 10$^{\circ}$grade. The control group received daily subcutaneous injection of normal saline at a dose of 4mg/kg body weight for 7 days. The D+E group ran on a treadmill for 60min/day(20minutes every 4 hours) at 10m/min and a 10$^{\circ}$ grade during dexamethasone injection. Body weight of the control group increased significantly from days of experiment, that of the dexa group decreased significantly from day 4 of the experiment resulting in a 82.4% decrease compared to the first day of the experiment. Body weight of the D+E group decreased significantly from day 5 of experiment resulting in a 81.77% decrease comprared to the first day of the experiment. Body weights, muscle weight and myofibrillar protein content of the plantaris and gastrocnemius decreased significantly and muscle weight of the soleus tended to decrease with dexamethasone injection. Glutamine synthetase activity of the hindlimb muscles increased significantly with the dexamethasone injection. The relative weight of the soleus was comparable to the control group and that of plantaris decreased significantly and that of gastrocnemius tended to decrease compared to that of the control in the dexa group. Body weight and muscle weight of the plantaris and gastrocnemius of the excrcise group were comparable to the control group, and the muscle weight of soleus showed a tendencey to increase. The relative weight of the soleus increased significantly and that of the plantaris and gastrocnemius were comparable to the control in the exercise group. Myofibrillar protein content of the soleus and plantaris increased significantly and there was no change of GS activity of the hindlimb muscles compared to the control in the exercise group. Body weight of the D+E group was comparable to the dexa group, muscle weight of the plantaris increased significantly and that of the soleus and gastrocnemius showed a tendency to increase. The relative weight of the hindlimb muscles increased significantly. Myofibrillar protein content of the soleus and plantaris increased significantly and that of the gastrocnemius tended to increase compared to the dexa group. Body weight and muscle weight of the plantaris and gastrocnemius of the D+E group did not recover to that of the control group. Muscle weight of the soleus recovered to that of the control group. The relative weight and of myofibrillar protein content of the hindlimb muscles recovered to that of the control group. From these results, it is suggested that regular exercise during dexamethasone injection might attenuate the muscle atrophy of the hindlimb muscles.