The aims of the present study were to examine the role of epoch length (time sampling interval) on locomotive and non-locomotive physical activity (PA) estimates and the relationships with obesity in healthy adults in each sex. Subjects were 308 Japanese women and 183 men aged 20-to-64years old. Time in locomotive and non-locomotive light PA (2.0 ~ 2.9METs; metabolic equivalents) and moderate-to-vigorous PA (MVPA, 3 METs or more) and step counts were assessed using a triaxial accelerometer (Active style Pro HJA-350IT, Omron Healthcare Co., Ltd) presented in 60s and 10s epochs. Body mass index (BMI) by height and body weight was calculated. There were significant differences between results by epoch lengths in both locomotive and non-locomotive PA. In particular, the difference was remarkable for non-locomotive PA. Time in each MVPA for women and men when presented in 10s epochs were significantly higher. Time in total MVPA was different by nearly 30min for women and nearly 20min for men. Moreover, time in non-locomotive light PA when presented as 60s epochs was significantly higher in both women and men than that when presented as 10s epochs, and time in total light PA showed an obvious difference of nearly 50min higher in 60s epochs for women. Conversely, the relationships between PA with 60sec and 10sec estimates and BMI were weak, even though over half of PA variables showed significant correlations. These findings suggest that non-locomotive PA evaluated by the triaxial accelerometer was obviously affected by epoch length. The finding also showed gender differences.
The purpose of this study was to examine whether volunteering as exercise instructors over a continuous period of time affected the physical and cognitive functions of community-dwelling, elderly women. Longitudinal analysis was conducted on data from 18 volunteer leaders (Leader group) aged 65-79 years (69.6 ± 3.9 years) and 18 age-matched survey participants (Control group). We evaluated physical function using 8 physical performance tests along with their standardized total score, and we evaluated cognitive function using the Five Cognitive Function Test. We used two-way ANOVA to examine the effectiveness of engaging in a yearlong volunteer activity and Cohen's d for effect size. There were significant interactions in timed up and go, hand working with pegboard, standardized score of performance tests and the Five Cognitive Function Test score (P < 0.05). The Leader group improved significantly in sit and reach (d = 0.55), 5-repetition sit-to-stand (d = 0.77), timed up and go (d = 0.77), 5-m habitual walk (d = 0.88), 4-way choice reaction time (d = 0.86), standardized score of performance tests (d = 0.96) and the Five Cognitive Function Test score (d = 0.93). Although the Control group also improved significantly in some tests, the effect size tended to be lower: sit and reach (d = 0.49), hand working with pegboard (d = 0.57), standardized score of performance tests (d = 0.38) and the Five Cognitive Function Test score (d = 0.54). These results suggest that volunteering as an exercise instructor improves volunteers' physical and cognitive functions.
Hamstring muscles form a multi-articular muscle group that crosses the hip and knee joints. It has been said that the imbalance in the hamstrings:quadriceps strength ratio (H:Q ratio) due to weaker hamstring muscles results in an increased susceptibility to hamstring strains and anterior cruciate ligament injuries. Four different hamstrings trainings, Hip Lift (HL), Single-leg Deadlift (DL), Leg Curl (LC), and Nordic Hamstrings (NH), were conducted and compared in the effect on conventional H:Q ratio. After the training of two months, significant increase of hip extension torque and H:Q ratios in the hip joint were found in the DL group, and significant increase of knee flexion torque and H:Q ratios in the knee joint were found in the LC group (P < 0.05). As a conclusion, DL and LC training could be practical for hamstrings injury prevention.
Since the effect of the submaximal aerobic exercise on bone had been controversial, the aim of this study was to elucidate the effect of the bench step (BS), that seemed to deliver higher mechanical load on bone than any other aerobic exercises, on the total bone mineral content (BMC) and the bone metabolism of menopausal women. Sixteen menopausal women (65 ± 9 years old) as the exercise group (ExG) and 28 pre-menopausal women (43 ± 3 years old) as the control group (CG) were studied. ExG carried out BS training with the exercise intensity at lactate threshold (LT) for 21 weeks. In ExG, BMC was measured by dual energy X-ray absorptiometry (DXA) at one year before the intervention (A year before), pre-intervention (Pre) and post-intervention (Post). Serum osteocalcin (OC) as the marker of bone formation and serum type I collagen cross-linked N-telopeptide (NTx) as the marker of bone absorption at Pre, 11th week of the intervention and Post. In CG, BMC was measured annually without the intervention. In ExG, OC was not changed, but NTx was significantly decreased by intervention (p<0.05). The decreased amount of annual change in BMC between a year before and Pre (T1) was significantly higher compared to that between Pre and Post (T2) (p<0.01) and CG (p<0.001). There was no significant difference between T2 and CG. In conclusion, BS with LT could prevent decreasing BMC in menopausal women, and maintain the same level of BMC in pre-menopausal women by suppressing the bone absorption.
This study examined relationships between physical activity and sleep relative to leisure-time, household, and occupational physical activity in community-dwelling, older adults. From 3,000 randomly chosen community-dwelling, adults, aged 65-85 years, we recruited 509 eligible subjects (mean age 73.2 ± 5.1 years). We assessed nocturnal sleep duration, sleep onset latency and subjective sleep quality over the previous month through a questionnaire. Physical Activity Scale for the Elderly was used to assess leisure-time, household, and occupational physical activity. Items pertaining to sleep were expressed as dichotomous variables (good/poor), and each physical activity score was divided into two categories based on activity level. To investigate the relationship between sleep (dependent variable) and physical activity (independent variable), we used a logistic regression analysis, controlling for age, gender, living arrangement, depressive symptoms, and cognitive function. Prolonged sleep latency was significantly related to no participation in low intensity exercise (OR 2.14; 95% CI 1.42-3.21) and muscle strength exercise (OR 1.99; 95% CI 1.06-3.74). Our data suggest that not participating in low intensity exercise or muscle strength exercise may be associated with difficulty initiating sleep in older adults.
This study aimed to determine the effects of wearing graduated elastic compression stockings (GCSs) on arterial stiffness. The study included 10 healthy men who were randomly assigned to undergo trials with and without GCSs on separate days. Baseline measurements of brachial-ankle pulse wave velocity (baPWV), heart rate, and brachial blood pressure (BP) were obtained in the supine position after the subjects had rested for 20 min without GCSs. The order of the trials (with or without GCSs) was set randomly. During both trials, data for these parameters were collected with the subjects in the supine position, after they had rested for 20 min. After both trials, the brachial BP did not significantly change from the baseline values. baPWV significantly decreased after trials with GCSs (from 1153.0 ± 123.4 to 1078.1 ± 134.3 cm/s, P < 0.05), but no significant difference was observed after trials without GCSs (from 1125.2 ± 118.7 to 1134.5 ± 100.9 cm/s). In addition, changes in volume after trials with GCSs (-74.9 ± 35.3 cm/s) were significantly lower than those after trials without GCSs (+9.3 ± 36.7 cm/s, P < 0.05). baPWV significantly decreased during supine rest on wearing GCSs. This decrease in baPWV was possibly caused by a decrease in arterial stiffness itself and/or a decrease in vascular transmural pressure that may have been due to increase in external pressure on the vasculature.