Mitochondria play a central role in energy production but also are the main cellular source of reactive oxygen species (ROS). It is widely believed that aging is related to the accumulation of oxidative molecular damage due to ROS. Aging also induces a decrease in muscle function. Recent studies indicate that caloric restriction and physical exercise suppress the decrease in muscle function though the maintaining quality of mitochondria. This review provides the current understanding of the influence of caloric restriction and exercise on mitochondrial quality control in skeletal muscle.
Research highlights the importance of maintaining pre-diagnosis physical activity levels for breast cancer survivors post-treatment. However, many survivors have difficulty engaging in physical activity due to cancer-related fatigue. The aim of this study was to explore how participation in a 12-week yoga intervention impacted fatigue and physical activity. 20 individuals with breast cancer diagnosis participated in a 12-week yoga intervention. The yoga intervention included modified hatha yoga postures and consisted of 10 min. of warm-up, 45 min. of yoga postures, 10 min. of breath work, and 10 min. of supine resting pose (savasana), for a total of 75 min. Assessments were administered at 3 time points: pre (T1), post (T2) yoga intervention and at a 12-week follow-up (T3). Measures included self-reported fatigue (Cancer Fatigue Scale) and physical activity (accelerometer step counts). One-way ANOVA were used to examine how fatigue scores and steps counts were changed over the course of the intervention. Total fatigue score (FS) and daily step (DS) counts at each time point were T1 (FS=21.6±8.9, DS=7709±2036), T2 (FS=14.0±8.3, DS=8429±2722), and T3 (FS=16.8±6.9, DS=8406±3389). Significant improvements in physical fatigue T1 (p<0.05, η2 = 0.14) and cognitive fatigue (p<0.01, η2 = 0.11) were seen at T1-T2. No significant changes were seen in psychological fatigue. 12 participants (65%) had high fatigue levels at T1, which decreased to 5 participants (27.8%) at T2. 12 participants (66.7%) increased daily steps at T2 and 8 participants (44.4%) continued to increase at T3. There were negative correlations between fatigue scores and step counts at all time points (r=-0.45~-0.55). Participation in a 12-week yoga program was associated with improved cancer-related fatigue.
The purpose of this study was to examine the effects of an exercise intervention for older married couples on exercise adherence and physical fitness. Thirty-six older married couples and 61 older adults participated in the study as couple and non-couple groups (CG, NCG, respectively). Participants attended an exercise class once a week and performed a home-based exercise program consisting of walking and strength exercise over eight weeks. Exercise adherence was assessed by the rate of non-absentee, walking habits (≥ 2 times/week), and strength exercise habits (≥ 6 items*2 sets/week). Physical fitness was assessed by the Senior Fitness Tests. Logistic regression analyses were conducted to obtain the CG’s odds ratios (ORs) and 95% confidence interval (CI) for non-absentee, walking habits, and strength exercise habits (reference: NCG). Analyses of covariance were used to examine the statistical difference in the degree of change (⊿) for physical fitness between CG and NCG. CG had significantly higher ORs for non-absentee and walking habits compared with NCG but there was no significant difference in the rate of strength exercise habits between the two groups. In regards to ⊿ for physical fitness, significantly higher ⊿ for upper extremity strength was observed in CG than in NCG, while there were no significant differences in ⊿ for other physical fitness items between the two groups. These results suggest that an exercise intervention for older married couples would be more useful to maintain higher participation in exercise program and walking and improving upper extremity strength.
This study aimed to evaluate dynamic balance capability, bathyesthesia, and the composite compensation of bathyesthesia and visual sense for dynamic balance assessed by use of force plates and to examine their correlation to age in a cross-sectorial manner. Participants of this study were 147 healthy people (55 men, 92 women). To evaluate dynamic balance capability, we evaluated the index of postural stability (IPS), which is the logarithmic value of the ratio of the area of stability limits to the area of postural sway, with participants standing on a hard surface with eyes opened. To measure bathyesthesia, we evaluated the modified index of postural stability (MIPS), i.e., the IPS with participants standing on a soft surface with eyes closed. As for the composite compensation index of bathyesthesia and visual sense for dynamic balance, we calculated the rubber IPS Romberg ratio (MIPS/IPS). The correlation coefficients (Spearman’s rho) of IPS, MIPS and MIPS/IPS to age were −0.666 (p < 0.001), −0.697 (p < 0.001) and −0.600 (p < 0.001), respectively. These results suggest that dynamic balance capability and bathyesthesia decline with advancing age, and the composite compensation of bathyesthesia and visual sense for dynamic balance strengthens with advancing age.
In animal studies, the motor nerve conduction velocity (NCV) is related to the axonal diameter of peripheral nerve. In humans, differences of NCV between dominant and non-dominant forearms have not been confirmed by the differences of the axonal diameter of peripheral nerve. Therefore, the purpose of this study was to measure the cross-sectional area of human ulnar nerve fascia (nCSA) directly and to examine the relationship between the NCV of the ulnar nerve and the nCSA in humans. The thirty healthy subjects were volunteered for this study. Electric stimuli were applied over the two separate points of the ulnar nerve and the latencies of this action potential in abductor digiti minimi muscles were measured, respectively. The NCVs in the forearms were calculated as the distances between two stimulating electrodes divided by the differences in their latencies. The five nCSA images from the medial epicondyle of the humerus to the ulnar head at equal intervals were measured by ultrasonography and averaged in each forearm, respectively. The maximum forearm circumferences (MFC) of both forearms were measured by a measuring tape. The NCV, nCSA and MFC were significantly greater in dominant than in non-dominant forearms. Although there is a significant positive relationship between the nCSA and MFC, nCSA cannot necessarily influence NCV. These results suggest that the size of human ulnar nerve fascia may not be necessarily related to the axonal diameter of ulnar nerve.
This study examined the association of physical activity (PA) and sedentary behavior (SB) with chronic low back pain (CLBP) in older adults. Cross-sectional data were collected from 715 elders aged 65 years and over living in Dazaifu, Japan. CLBP was defined as pain that sustains more than 1-3 months within the past year. PA and SB were objectively measured using a triaxial accelerometer (Omron Healthcare, Active style Pro (HJA 350IT)). Participants were categorized into four groups (2 groups of PA×2 groups of SB) according to their levels of PA and SB (divided into 2 levels; low and high levels around the median). Logistic regression analysis was used to examine effect of PA/SB with CLBP. In the analyses, sex, age, body mass index, smoking, educational attainment, falls, handgrip strength, knee pain and non-locomotive activities were treated as potential confounders. The prevalence of CLBP was 35%. After adjustment of confounding factors, significantly higher risk of CLBP was shown only in Low PA/High SB group (odds ratio : 1.66, 95% confidence interval : 1.02-2.70), compared with that of the reference group (High PA/Low SB group). These results suggest that the combination of low PA and high SB might be the risk of CLBP. Future studies should try to clarify whether CLBP is a cause or a consequence of inactivity.
This study aimed to examine the relationship between daily outdoor playing time assessed using questionnaires for parents and daily moderate-to-vigorous physical activity (MVPA) using triaxial accelerometers for young children (213 boys: 5.8±0.6years and 193 girls: 5.9±0.6years). The study also examined the potential relationships between daily MVPA and exercise habits or familial and preschool factors which were assessed using questionnaires for parents. Daily MVPA was assessed using a triaxial accelerometer (ActivTracer, GMS) for 6 consecutive days, including weekdays and weekends. Outdoor playing time and percentage of outdoor playing time more than 60 min/day were 81±62 min/day and 64% for boys and 78±61 min/day and 62% for girls, respectively. Outdoor playing time was not significantly correlated with MVPA. The study found that no factors for MVPA, including exercise habits, were correlated with MVPA when adjusted for age, body height and log-body weight, except that MVPA for girls in kindergartens was higher than that in nursery schools. These findings suggest that the percentage of outdoor playing time more than 60 min/day was about 2/3 in young children. The questionnaire didn't reflect their MVPA. The factors used in the present study except for the preschool type for girls may not contribute to the time spent in MVPA in preschool children.
To analyze the relationship of cause and effect between the onset of throwing disorders of the shoulder and decreased muscle strength, two studies were conducted at a baseball field. In study 1, shoulder joint muscle strength was measured when pain developed during practice and the relationship between pain onset and muscle strength was investigated. Decreased muscle strength was noted at the time of pain onset in 8.1% of players. Study 2 was a prospective study in which the relationship between changes in shoulder joint muscle strength from the start of pitching at the beginning of the season to one month later when competitive games began, and shoulder pain that appeared at the beginning of competitive games was analyzed. Based on the results, the possibility of shoulder joint muscle strength being a predictive factor for the onset of throwing disorders of the shoulder was investigated. However the pain group had greater muscle strength than the normal group at the beginning of the season. On the baseball field, the players’ throwing motions and joint function change daily, making it difficult to determine the reason for onset of disorders and injuries. These results suggest that onset of pain at the start of competitive games cannot be predicted from muscle strength at the beginning of the season.