PURPOSE: Sarcopenia, also known as the age-related loss of muscle mass and muscle fitness, and physical performance, has been related to many adverse health outcomes. Resistance exercise may have an important role in effecting strategy for sarcopenia in aging populations. The purpose of this study is to systematically assess the effects resistance exercise interventions on muscle mass, muscle strength, and physical performance in elderly diagnosed with sarcopenia.
METHODS: A comprehensive search on electronic databases, including PubMed, EMBASE, CINAHLPlus, SPORTDiscus, KERIS, KISS, and NAL were conducted. Eligible studies were divided into exercise and randomized controlled trials in elderly with sarcopenia. Searches retrieved 1,067 titles. Eighty full texts were evaluated, and seven studies were used for final systematic reviews. CMA (Comprehensive Meta-Analysis) ver 3.0 was used for meta-analysis.
RESULTS: Meta-analysis showed that lower muscle mass (ES=0.579, 95% CI: 0.266-0.892, p=.000), appendicular muscle mass (ES=0.341, 95% CI: 0.006-0.676, p=.046), right hand grip strength (ES=0.739, 95% CI: 0.216-1.262, p=.006), left hand grip strength (ES=0.692, 95% CI: 0.167-1.217, p=.010), knee extension strength (ES=1.448, 95% CI: 0.273-2.624, p=.016), and timed up and go (ES=1.471, 95% CI: 0.492-2.450, p=.003) significantly improved in response to resistance exercise programs.
CONCLUSIONS: Sarcopenia is increasing with the growing elderly population; thus prevention and effective interventions are very important. The data suggest that resistance exercise may be actual in enhancing not only appendicular muscle mass, but also knee extension strength and timed up and go in elderly diagnosed with sarcopenia. Further follow-up studies on larger populations and a variety of approaches are required to reconfirm these results.

PURPOSE: The purpose of this study was to confirm the kinematic characteristics of overuse leg injuries during gait through a systematic review.
METHODS: Electronic databases from 1960 to 2018 were used to search studies. Physiotherapy Evidence Database Scale was used for quality of studies. Effect sizes (ES) of between-groups and its 95% confidence intervals were calculated.
RESULTS: Seven studies were selected for review. The average Physiotherapy Evidence Database Scale score was 4.3 of 10-point scale. The ES for maximum rearfoot eversion from 5 studies ranged from -0.34 to 0.67 with 3 of 5 studies statistically significant. The ES of eversion excursion from 4 studies ranged from -0.24 to 2.37 and 3 of 4 studies showed statistically significant. The ES of maximum eversion velocity ranged from 0.29 to 0.38 from all of 2 studies. With abduction, the ES for abduction excursion ranged from -0.04 to 0.35, and 2 of 3 studies revealed statistically significant. The ES of maximum abduction velocity showed statistically significant with the ES of 0.23 and 0.61. However, maximum abduction from 3 studies showed non-significant with ES ranges from 0.00 to 0.62.
CONCLUSIONS: The rearfoot motion (eversion) associates with overuse leg injuries during gait more than tibial motion (internal rotation).

PURPOSE: A number of physiological diagnostics were developed. However, the timeline-related diagnostics of maximal anaerobic glycolytic capacity remain unclear. The objective of this study was to evaluate the reliability and validity of a sprint running test to assess the anaerobic capacity.
METHODS: The study was divided into three parts. Sixty-one male (24±4 years, 181.0±4.3 cm; 78.5±5.9 kg) and twelve female (25±3 years, 167.0±0.6 cm, 60.4±5.7 kg) sports students participated in this study. Twenty-five subjects (13 males, 24±2 years, 181.0±0.5 cm, 78.5±5.9 kg; 12 females, 25±3 years, 167.0±0.6 cm, 60.4±5.7 kg) performed incremental step tests at running track and several linear sprints on a running track (LSRT) with different time durations (8, 10, 12, and 14 seconds)(part I) on different days. Twenty-five male subjects (24±3 years, 180.7±6.7 cm, 84.6±8.8 kg) conducted a 10 or 12 second sprint running on a non-motorized treadmill (NMT)(part II). In part III, twenty-three male subjects (24±2 years, 181.4±5.8 cm, 74.5±7.4 kg) ran a 10 second LSRT and NMT on consecutive days. Capillary blood samplings were taken before (Lacr) and after the sprint running for ten minutes at one minute intervals to find out maximal lactate concentration after exercise and to calculate the maximum lactate production rate (LPRmax).
RESULTS: For all parts reliability for LPRmax was proven (Part I: 8 seconds: ICC: r=.89; 10 seconds: ICC: r=.82; 12 seconds: ICC: r=.92; 14 seconds: r=.84, respectively; Part II: 10 seconds: ICC: r=.76; 12 seconds: ICC: r=.79). To analyze validity for LPRmax, Part III was conducted and proven valid (ICC: r=.96, p=.074).
CONCLUSIONS: We demonstrate that LSRT and NMT reliably determine anaerobic capacity and can be used as a valid tool for physiological performance diagnostics.

PURPOSE: Osteoporosis is a public health problem that requires constant attention in an aging society. This study examines the effects of 12 weeks of resistance training on serum sex steroid hormone and bone metabolism factors in orchiectomized rats.
METHODS: A total of 30 male Sprague-Dawley (20 week-old) rats divided into three groups; (1) CON (normal-control, n=10), (2) ORX-CON (orchiectomized-control, n=10), (3) ORX-RE (orchiectomized-resistance exercise, n=10). The resistance training performed ladder climbing (8 repetitions, three days per week for 12 weeks) starting 1 week after surgery.
RESULTS: The investigation revealed that compared to the CON group, the ORX-CON group showed significantly lower levels of testosterone, dihydrotestosterone (DHT), grip strength, bone mineral density (BMD) and breaking force, but much higher levels of osteocalcin and CTx-1. The ORX-RE group showed increased grip strength, hormones (testosterone and DHT), osteocalcin, and BMD compared to ORX-CON group.
CONCLUSIONS: These findings suggest that resistance exercise training may be an intervention strategy for prevention osteoporosis and fracture in male aging process.

PURPOSE: This study investigated the association between estimated cardiorespiratory fitness (eCRF) and all-cause mortality in underweight older adults.
METHODS: Data from the 2006 Korean longitudinal study of aging (KLoSA) involving 348 study participants aged 60 years and older (58.0% women) was analyzed in this study. CRF was estimated with sex- and age-specific algorithms developed by the fitness registry and the importance of exercise national database (FRIEND). Participants were classified into lowest 25% (Q1), lower 25% (Q2), middle 25% (Q3), and highest 25% (Q4) on the basis of individual eCRF distributions. Cox proportional hazards regression was used to calculate hazard ratio (HR) and 95% confidence interval (CI) according to eCRF levels.
RESULTS: During 7.8±3.2-year follow-up period, a total of 175 deaths occurred from all causes. Cox regression analysis showed that HR of all-cause mortality was 0.686 (95% CI, 0.474-0.991, p=.045) for Q2, 0.382 (95% CI, 0.253-0.575, p<.001) for Q3, and 0.248 (95% CI, 0.155-0.397, p<.001) for Q4 compared to Q1 as reference (HR=1). The HR of Q4 for all-cause mortality remained significant even after adjustments for covariates, including age and marital status.
CONCLUSIONS: The current findings suggest that high eCRF is associated with a decreased risk of all-cause mortality in underweight older adults.

PURPOSE: The purpose of this study was to investigate the effects of 5 weeks of basic military training on the physical fitness and blood biochemical factors in obese military recruits.
METHODS: Forty-eight male recruits (20-25 years of age) were randomly assigned to the Control group and Exercise group. Both groups completed 5 weeks of basic military training. The Exercise group additionally performed a resistance exercise twice daily in the morning and afternoon (1-3 sets, 3 days per week) and power walking (60-80% HRmax, 30 minutes) four times weekly. Four body composition variables, physical fitness factors, serum lipid profiles, and obesity-related hormone levels were analyzed.
RESULTS: Body weight, body fat ratio, body mass index, and waist circumference were significantly decreased in both groups between pre- and post-exercise tests (p<.01). However, no changes in these parameters were observed between the Control and Exercise groups. Twenty-meter shuttle running and maximal oxygen uptake were significantly increased post exercise (p<.001). Total cholesterol, triglyceride, and low-density lipoprotein levels were significantly decreased in both (Control and Exercise) post-exercise tests (p<.05). Leptin in both groups was significantly decreased; however, ghrelin showed a reverse pattern (p<.01). A significantly changed maximal oxygen uptake value via training was noted in both groups (p<.001). The time and interaction between the groups and the time were also significantly affected (p<.001).
CONCLUSIONS: Our findings suggest that an additional exercise-training program with the basic military training plays an important role in improving military fitness and combat power.

PURPOSE: This study aimed to compare the acute effects of different types (treadmill vs. cycle) of moderate-intensity aerobic exercise on cerebral blood flow and cognitive function in young adults.
METHODS: By a randomized crossover study design, ten participants were initially assigned to either treadmill exercise (TE; n=5) or cycle ergometer exercise (CE; n=5) and then they performed the other with seven-day wash-out period. Both exercises were implemented at the target heart rate corresponding to 70% of heart rate reserve for 30 minutes. Cognitive function was assessed by the Stroop Color-Word test at pre- and post-exercise. Cerebral blood flow was continuously monitored using near-infrared spectroscopy technique during rest, cognitive function test (CFT), and exercise.
RESULTS: There was a significant group by time interaction in tissue saturation index (TSI) (p=.046). Post-hoc analysis presented that TSI at post-exercise CFT was higher than during exercise in TE (p=.02). In both exercises, TSI at pre-exercise CFT significantly increased compared to the resting value (p=.001). Cerebral oxyhemoglobin level was significantly increased during exercise and at post-exercise CFT compared to the resting value in both exercises (p<.001). The reaction time for certain cognitive tasks such as color, word with matched color, word with color interference, and color with word interference was improved after both exercises (p<.05).
CONCLUSIONS: One-bout of moderate-intensity aerobic exercise acutely improves cerebral blood flow and cognitive function even in healthy young adults. Exercise types with the same intensity do not seem to make meaningful difference in the positive effects of aerobic exercise.

PURPOSE: The purpose of this study was to investigate the relationship of smartphone use time, sitting time, and fitness level in university students.
METHODS: The participants of this study were 237 healthy university students (157 males and 80 females) enrolled from 2017 to 2018. The smartphone use time was divided into three groups: 0-4, ≥4-10, and ≥10 hours, as was the sitting time: 0-4, 4-7, and ≥7 hours. Binary logistic regression was used to calculate the odd ratio (OR) and 95% confidence interval (CI) of the smartphone use time and sitting time for having low levels of fitness.
RESULTS: There were linear decreases in physical fitness levels across incremental smartphone use time and sitting time. Compared to the smartphone use time for 0-4 hours (reference), smartphone use time for the ≥4-10 hours (OR=2.498; 95% CI=1.007-6.197; p=.048) or the 10≥group (OR=3.516; 95% CI=1.228-10.064; p=.019) had significantly higher ORs of having lower fitness even after adjustments for age, sex, physical activity and percent body fat. Likewise, logistic regression analyses showed that those who had sitting time for ≥7 hours (OR=3.135; 95% CI=1.155-8.512; p=.025) had significantly higher ORs of having lower fitness even after adjustments for age, sex, physical activity, and percent body fat, as compared with those who had sitting time for 0-<4 hours.
CONCLUSIONS: The current finding suggest that the smartphone using time and sitting time were associated with having the risk of lower level of physical fitness in university students.

PURPOSE: The purpose of this study was to analyze the effects of aerobic exercise on the expression of synaptic vesicle transporter and antioxidant enzymes in obesity and to investigate the feasibility of exercise training to reduce AD pathogenesis in the 3xTg-AD mice fed a high fat diet.
METHODS: Male 3 month old 3xTg-AD mice were divided into standard chow(SC, n=10), standard chow+exercise (SC-EXE, n=10), high fat diet (HFD, n=10), and high fat diet+exercise (HFD-EXE, n=10) groups. EXE mice were subjected to treadmill running at a moderate intensity with duration of 30 minutes per day and frequency of 5 days per week for 12 weeks. HFD mice were fed a 60% fat HFD during the same period. Mice were sacrificed and immunohistology and western blot analysis were performed.
RESULTS: Compared with the SC mice, the HFD mice had significantly higher levels of Aβ (p<.01), p-tau/t-tau (p<.01) and defects of Vglut1 (p<.05), VGAT (p<.05), postsynaptic density 95 (p<.01) and GPX (p<.05) in the hippocampus. On the other hand, we found that treadmill running attenuated HFD-induced exacerbations of Aβ (p<.01), p-tau/t-tau (p<.05) and defects of Vglut1 (p<.01), Synaptophysin (p<.05), SOD1 (p<.05) in the hippocampus.
CONCLUSIONS: High fat diet-induced obesity resulted in increased AD neuropathology and decreased synaptic vesicle transporter and antioxidant enzyme in the hippocampus of 3xTg-AD mice. However, aerobic exercise delayed AD-like disease progression, alleviated impaired synaptic function and the decreased expression of antioxidant enzymes in the hippocampus.