Nayoung Ahn

Effects of an elastic band resistance exercise program on lower extremity muscle strength and gait ability in patients with Alzheimer’s disease

[Purpose] This study examined the effects of a resistance exercise programs aiming to improve muscular function in order to prevent and treat Alzheimer’s disease in elderly people. [Subjects and Methods] Elderly patients with mild dementia were randomly assigned to an elastic band resistance exercise group (74.21±6.09 years). The experimental group (n=23) performed upper and lower extremity exercises three times per week for five months. Physical fitness was measured according to chair leg squat, one-leg stance, timed up-and-go test, 2-minute walking test, and gait ability before and after exercise. [Results] Static balance ability in which the participant stood on one foot with eyes open (left and right) increased significantly, but the dynamic balancing ability in the timed up-and-go test did not improve significantly. Cardiorespiratory function and gait speed improved significantly. [Conclusion] The five-month elastic band resistance exercise program improved muscle strength and endurance, cardiovascular function, and gait speed. Therefore, it may be an effective rehabilitation program for elderly patients with Alzheimer’s disease.

Effects of Cold Environment Exposure and Cold Acclimatization on Exercise-Induced Salivary Cortisol Response

Abstract Objective.—Considering the adverse effects of exercise-induced cortisol secretion on health in athletes, it is important to determine the environmental and individual factors that contribute to the variations in exercise-induced cortisol secretion. In this study, the effects of cold environment exposure and cold acclimatization on exercise-induced salivary cortisol responses were investigated. Methods.—Short track skaters (n  =  11), who usually practice under cold conditions, and inline skaters (n  =  11), who usually practice under room temperature conditions, participated in a randomized crossover study. All participants cycled for 60 minutes at 65% V˙o2 max under cold (ambient temperature: 5 ± 1°C, relative humidity 41% ± 9%) and room temperature (ambient temperature: 21 ± 1°C, relative humidity 35% ± 5%) conditions. The participants had a 120-minute bed rest recovery phase at room temperature after both exercise bouts. Cortisol levels were measured in saliva samples collected pre-exercise and postexercise at 1 minute, 30 minutes, 60 minutes, and 120 minutes. Results.—Both short track and inline skaters exhibited clear cortisol responses to exercise under cold and room temperature conditions. The magnitude of the cortisol response, however, was different between skaters and conditions. The inline skaters exhibited significantly higher cortisol values under cold conditions than under room temperature conditions (7.6 nmol/L and 4.2 nmol/L, respectively). However, the short track skaters exhibited significantly higher cortisol values under cold conditions compared to room temperature conditions (8.7 nmol/L and 5.4 nmol/L, respectively). Conclusions.—The effects of cold environment exposure on exercise-induced cortisol response were different between skaters who usually practice under cold or room temperature conditions. These results can be interpreted as acclimatization to either cold or room temperature conditions attenuating the cortisol response, suggesting that acclimatization may be beneficial in reducing the exercise-induced cortisol response.

PHYSIOLOGICAL AND LEUKOCYTE SUBSET RESPONSES TO EXERCISE AND COLD EXPOSURE IN COLD-ACCLIMATIZED SKATERS

We investigated physiological responses and changes in circulating immune cells following exercise in cold and thermoneutral conditions. Participants were short track skaters (n=9) who were acclimatized to cold conditions, and inline skaters (n=10) who were not acclimatized. All skaters were young, and skating at a recreational level three days per week for at least one year. Using a cross-over design, study variables were measured during 60 min of submaximal cycling (65% V.O2max) in cold (ambient temperature: 5±1°C, relative humidity: 41±9%) and thermoneutral conditions (ambient temperature: 21±1°C, relative humidity: 35±5%). Heart rate, blood lactate and tympanic temperature were measured at rest, during exercise and recovery. Plasma cortisol, calprotectin and circulating blood cell numbers were measured before and after 60 min of cold or thermoneutral conditions, and during recovery from exercise. Heart rate was lower in both groups during exercise in cold versus thermoneutral conditions (P<0.05). The increase in total leukocytes during recovery was primarily due to an increase in neutrophils in both groups. The cold-acclimatized group activated neutrophils after exercise in cold exposure, whereas the non-acclimatized group activated lymphocyte and cortisol after exercise in cold exposure. Lymphocyte subsets significantly changed in both groups over time during recovery as compared to rest. Immediately after exercise in both groups, CD16+ and CD69+ cells were elevated compared to rest or before exercise in both conditions. Acclimatization to exercise in the cold does not appear to influence exercise-induced immune changes in cold conditions, with the possible exception of neutrophils, lymphocytes and cortisol concentration.

High-density lipoprotein cholesterol (HDL-C) in cardiovascular disease: effect of exercise training

Decreases in high-density lipoprotein cholesterol (HDL-C) levels are associated with an increased risk of coronary artery disease (CAD), whereas increased HDL-C levels are related to a decreased risk of CAD and myocardial infarction. Although HDL prevents the oxidation of low-density lipoprotein under normal conditions, it triggers a structural change, inhibiting antiarteriosclerotic and anti-inflammatory functions, under pathological conditions such as oxidative stress, inflammation, and diabetes. HDL can transform into various structures based on the quantitative reduction and deformation of apolipoprotein A1 and is the primary cause of increased levels of dysfunctional HDL, which can lead to an increased risk of CAD. Therefore, analyzing the structure and components of HDL rather than HDL-C after the application of an exercise training program may be useful for understanding the effects of HDL.

Combined influence of dietary restriction and treadmill running on MCP-1 and the expression of oxidative stress-related mRNA in the adipose tissue in obese mice.

[Purpose] This study suggests that the negative effects of inflammation caused by obesity could be prevented through diet restriction and exercise. [Methods] In this study, 44 C57/BL6 male mice at about 4 weeks old (Orient bio, South Korea) were given a high fat diet for 5 weeks to make them obese. To help the mice lose weight, their dietary intake was limited and they were exercised on the treadmill for 8 weeks, and during that period, we analyzed the changes of MCP-1, ERK, Mn-SOD, HIF-1, and NOX in epididymal adipose tissue. There ND control group and obese group with high fat diet (HFD), and it is divided into four groups; HFD-ND-EX group, HFD-ND-nonEX group, HFD-DR-EX group and HFD-DR-nonEX group. [Results] During their progress, the mRNA expressions of HIF-1α and ERK2 decreased, as did the expression of MCP-1 contained in the nucleus by suppressing oxygen free radicals, which was observed after the exercise program. However, dietary restriction without exercise training triggered an increase in the mRNA expression of MCP-1. [Conclusion] To put this in perspective, combining exercise and dietary intake restriction likely prevented an influx of macrophages by reducing the number of fat cells, whereas only dietary restriction was not effective against reducing inflammation.

Association of angiotensin-converting enzyme I/D and α-actinin-3 R577X genotypes with metabolic syndrome risk factors in Korean children

OBJECTIVE This study analysed the risk factors associated with metabolic syndrome through the interaction between ACTN3 and ACE gene polymorphism in Korean children. METHODS The subjects of the study consisted of elementary school students (n=788, age 10.10±0.07 yr). The anthropometric parameters, blood lipid profiles, and metabolic markers were compared among groups of the ACE I/D or the ACTN3 R577X polymorphisms. RESULTS The subjects with the DD genotype showed significantly higher systolic blood pressure than the subjects with the II and ID genotype of the ACE gene polymorphism. XX genotype had significantly lower waist-hip ratio than those with RR genotype of the ACTN3 gene polymorphism. Also, the subjects with XX genotype exhibited significantly higher blood HDL cholesterol level than those with RR or RX genotype. The interaction of ACTN3 and ACE gene polymorphism in subjects having both ACE DD and ACTN3 RR genotypes demonstrated a significantly higher metabolic syndrome score than any other groups. CONCLUSION The children having both ACTN3 RR or RX genotype and ACE DD genotype showed high systolic blood pressure and low blood HDL cholesterol level, which may be considered a high-risk in metabolic syndrome.

Association of Angiotensin Converting Enzyme I/D and α-actinin-3 R577X Genotypes with Growth Factors and Physical Fitness in Korean Children

This study analyzed the differences in aerobic and anaerobic exercise ability and growth-related indicators, depending on the polymorphism of the ACE and the ACTN3 genes, to understand the genetic influence of exercise ability in the growth process of children. The subjects of the study consisted of elementary school students (n=856, age 10.32±0.07 yr). The anthropometric parameters, physical fitness and growth factors were compared among groups of the ACE I/D or the ACTN3 R577X polymorphisms. There were no significant differences between the anthropometric parameters, physical fitness and growth factors for the ACE gene ID or the ACTN3 gene R577X polymorphism. However, the DD type of ACE gene was highest in the side step test (p<0.05), and the DD type was significantly higher than the II+ID type (p<0.05) in the early bone age. The combined group of the ACE gene II+ID and the ACTN3 gene XX type significantly showed lower early bone age (p< 0.05). This study did not find any individual or compounding effects of the polymorphism in the ACE I/D or the ACTN3 R577X polymorphisms on the anthropometric parameters, physical fitness and growth factors of Korean children. However, the exercise experience and the DD type of the ACE gene may affect the early maturity of the bones.

THE INFLUENCE OF OBESITY AND AMBIENT TEMPERATURE ON PHYSIOLOGICAL AND OXIDATIVE RESPONSES TO SUBMAXIMAL EXERCISE

This study investigated the effects of obesity and ambient temperature on physiological responses and markers of oxidative stress to submaximal exercise in obese and lean people. Sixteen healthy males were divided into an obese group (n=8, %fat: 27.00±3.00%) and a lean group (n=8, %fat: 13.85±2.45%). Study variables were measured during a 60 min submaximal exercise test at 60% VO2max in a neutral (21±1°C) and a cold (4±1°C) environment. Heart rate, blood lactate, rectal temperature, serum levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were measured at rest, during exercise and in recovery. Heart rate of both groups was significantly lower (P<0.05) in the cold than the warm environment, but there were no significant differences between the two groups. Serum SOD activity increased to a significantly greater extent (P<0.05) in the cold than the neutral environment, and remained elevated for longer during exercise in the obese group than the lean group. Serum MDA level during submaximal exercise was not significantly different between conditions or groups. Cold stress in exercise may challenge antioxidant defence mechanisms in obese subjects, but lipid peroxidation remains unchanged.

Effects of Resistance Exercise and Fermented Soybean Consumption on Glucose Tolerance and Expressions of Immune Senescence-Related Myokines in Middle-Aged Obese Rats

Background It is important for older adults to prevent sarcopenia, but there are not currently effective methods to maintain or improve skeletal muscle function or immune function in this population. The goal of this study was to observe the effects of a 12-week resistance exercise program with fermented soybean supplementation on glucose tolerance and myokine expression in middle-aged obese rats in regard to body composition and immune senescence. Methods Subjects were randomly assigned to four groups: control (CON), soybean (SO), resistance exercise (RE), and soybean plus resistance exercise (SR). Resistance exercise involved ladder climbing, and soybean supplementation comprised 24% of total calories from soybean protein. Obesity was induced with 6 weeks of a high-fat diet, and then the group-specific procedures were conducted for the following 12 weeks. Results There were no significant differences between the groups in regard to daily dietary intake and body weight. The SO group had significantly higher intraperitoneal fat levels compared to the CON group (P<0.05), and a significantly lower lean body mass (P<0.05). The glycemic response of the SO group and SR group showed significantly higher improvements compared to the CON group and RE group (P<0.05). The expression of myokines related to immune senescence was significantly lower in the SO group (P<0.05). Conclusion Fermented soy beans helped improve glucose tolerance when it was applied with and without resistance exercise, with a significant reduction in the expression of inflammatory factors related to immune senescence in skeletal muscle.

The effects of resistance elastic bands exercises on salivary IgA and salivary cortisol levels in elderly women

This study investigated the effect of a resistance exercise program using elastic bands for the enhancement of immune function and prevention of metabolic disorders, as measured by levels of salivary cortisol (sCor) and salivary immunoglobulin A (sIgA). Twenty-two elderly women were divided into an exercise group (77.91 ± 1.41 y) and a control group (78.73 ± 1.51 y). The exercise group performed resistance exercises with an elastic band at a frequency of 3 times/week and 60 min/day for 4 months. Physical fitness and levels of sCor and sIgA compared between before and after the exercise program. A significant increase in the number of lifts made in a lift dumbbell test was observed after the exercise program for both the left (p<0.05) and right (p<0.01) arms, indicating an improvement in upper limb muscular endurance. The number of steps on a 2 min walking in place test was also significantly increased following the exercise program (p<0.01), indicating improved cardiorespiratory function. Levels of sCor and sIgA reduced following the exercise program, but not by a statistical significance. A negative, but not significant, correlation was find between sIgA and sCor levels. In conclusion, the resistance exercise program using elastic bands conducted in our study improved the physical fitness. However, the exercise durations were too short to achieve a meaningful reduction of stress factors and improvements in the immune function. In future research, duration and intensity of exercise is modified to achieve greater improvements in the immune function of elderly people.