Abstract
The use of body weight support (BWS) can reveal important insights into the relationship between lower-limb muscle activities and the ventilatory response during sinusoidal walking. Here, ...healthy participants (n = 15) walked on a treadmill while 0%, 30%, and 50% of their body weight was supported with BWS. The walking speed was varied sinusoidally between 3 and 6 km h
−1
, and three different frequencies, and periods ranging from 2 to 10 min were used. Breath-by-breath ventilation (
$${\dot{\text{V}}}_{{\text{E}}}$$
V
˙
E
) and CO
2
output (
$${\dot{\text{V}}}\text{CO}_{{2}}$$
V
˙
CO
2
) were measured. The tibialis anterior (TA) muscle activity was measured by electromyography throughout the walking. The amplitude (
Amp
), normalized
Amp
Amp
ratio (%), and phase shift (
PS
) of the sinusoidal variations in measurement variables were calculated using a Fourier analysis. The results revealed that the
Amp
ratio in
$${\dot{\text{V}}}_{{\text{E}}}$$
V
˙
E
increased with the increase in BWS. A steeper slope of the
$${\dot{\text{V}}}_{{\text{E}}}$$
V
˙
E
–
$${\dot{\text{V}}}\text{CO}_{{2}}$$
V
˙
CO
2
relationship and greater
$${\dot{\text{V}}}_{{\text{E}}}$$
V
˙
E
/
$${\dot{\text{V}}}\text{CO}_{{2}}$$
V
˙
CO
2
values were observed under reduced body weight conditions. The
Amp
ratio in TA muscle was significantly positively associated with the
Amp
ratio in the
$${\dot{\text{V}}}_{{\text{E}}}$$
V
˙
E
(p < 0.001). These findings indicate that the greater amplitude in the TA muscle under BWS may have been a potent stimulus for the greater response of ventilation during sinusoidal walking.
We investigated the effects of moderate hypoxia (FiO2 = 15%) on different kinetics between pulmonary ventilation (Formula: see text) and heart rate (HR) during treadmill walking. Breath-by-breath ...Formula: see text, oxygen uptake (Formula: see text), carbon dioxide output (Formula: see text), and HR were measured in 13 healthy young adults. The treadmill speed was sinusoidally changed from 3 to 6 km·h-1 with four oscillation periods of 1, 2, 5, and 10 min. The amplitude (Amp), phase shift (PS) and mean values of these kinetics were obtained by harmonic analysis. The mean values of all of these responses during walking at a sinusoidally changing speed became greater under hypoxia compared to normoxia (FiO2 = 21%), indicating that moderate hypoxia could achieve an increased energy expenditure (increased Formula: see text and Formula: see text) and hyperventilation. The Amp values of the Formula: see text, Formula: see text, and Formula: see text kinetics were not significantly different between normoxia and hypoxia at most periods, although a significantly smaller Amp of the HR was observed at faster oscillation periods (1 or 2 min).The PS of the HR was significantly greater under hypoxia than normoxia at the 2, 5, and 10 min periods, whereas the PS of the Formula: see text, Formula: see text, and Formula: see text responses was not significantly different between normoxia and hypoxia at any period. These findings suggest that the lesser changes in Amp and PS in ventilatory and gas exchange kinetics during walking at a sinusoidally changing speed were remarkably different from a deceleration in HR kinetics under moderate hypoxia.
The Kyoto-Kameoka Study was launched in 2011-2012 to identify the associations among food intake, nutritional status, physical activity, oral function, quality of life or social capital, the use of ...long-term care insurance (LTCI) system, and healthy lifespan in community-dwelling older people as a part of the World Health Organization Safe Community program.
A prospective cohort study, reporting baseline demographics (cross-sectional data).
We conducted 2 mailed self-administered questionnaire surveys; one is a complete population survey with a comprehensive survey of needs in the sphere of daily life (NSDL) that included 2 different frailty indexes, the Kihon Checklist (KCL) and the Fried phenotype, socioeconomic status, general and psychological health, and social relationships; followed by the more detailed Health and Nutrition Survey. A slightly modified NSDL survey was conducted again in 2013. Survival time, LTCI certification, and medical and long-term care costs after the baseline survey will be followed.
Of 18,231 NSDL questionnaires distributed, 13,294 people responded (response rate: 72.92%; mean age 73.7 ± 6.4 and 75.1 ± 7.2 years for men and women, respectively; 12,054 people without and 1240 with LTCI certification). In people without LTCI, the proportion of robust, prefrail, and frail were 30.3%, 59.8%, and 9.9% in men and 25.3%, 64.7%, and 10.0% in women, according to the Fried index. The proportion of frail people as defined by KCL ≥7 was 30.8% in men and 33.3% in women.
The study is the first to document frailty prevalence using both Fried and KCL measures with a complete city population survey among older Japanese in the community as a part of World Health Organization Safe Community program. The study is expected to provide valuable evidence of the effects of lifestyle habits on long-term care prevention and healthy life span.
Abstract
Background
Appropriate energy intake (EI) is essential to prevent frailty. Because self-reported EI is inaccurate and has systematic errors, adequate biomarker calibration is required. This ...study examined the association between doubly labeled water (DLW)-calibrated EI and the prevalence of frailty among community-dwelling older adults.
Method
A cross-sectional study was performed using baseline data of 7,022 older adults aged ≥65 years in the Kyoto-Kameoka Study. EI was evaluated using a validated food frequency questionnaire (FFQ), and calibrated EI was obtained from a previously established equation using the DLW method. Physical and comprehensive frailty were defined by the Fried phenotype (FP) model and the Kihon Checklist (KCL), respectively. We used multivariable-adjusted restricted cubic spline logistic regression analysis.
Results
The prevalence of physical frailty was 14.8% and 13.6% in women and men, respectively. The spline models showed significant reverse J-shaped or U-shaped relationships between the prevalence of physical or comprehensive frailty against the DLW-calibrated EI, respectively. The lowest prevalence of both types of frailty was found at 1,900–2,000 kcal/d in women and 2,400–2,500 kcal/d in men, which corresponded to approximately 40 kcal/d/kg IBW (ideal body weight = 22 × height2) with DLW-calibrated EI. Uncalibrated EI underestimated approximately 20% compared with calibrated EI; underestimated EI were attenuated by calibration approach.
Conclusions
This study suggests that low EI has a greater detrimental effect compared with excessive EI, particularly on physical frailty. Using biomarkers to calibrate EI holds promise for providing accurate energy requirements to establish guidelines used in public health and clinical nutrition.
This study investigated how various genres of video viewing affected energy expenditure in a sitting position using landscape, horror, and animation videos. Energy expenditures were measured using ...the Douglas bag method for 12 female university students. The result obtained from each video task was compared with the resting energy expenditure during sedentary seating and showed no difference between energy expenditures while video viewing with resting energy expenditure. In addition, Bland-Altman analysis displayed proportional bias with the landscape video, meanwhile it showed the smallest variation with the animation video. It was indicated that animation videos viewing might be comparable and substitutable to sedentary seating.
High-intensity exercise in athletes results in mainly the production of excess reactive oxygen species (ROS) in skeletal muscle, and thus athletes should maintain greater ROS scavenging activity in ...the body. We investigated the changes in six different ROS-scavenging activities in athletes following high-intensity anaerobic exercise. A 30-s Wingate exercise test as a form of high-intensity anaerobic exercise was completed by 10 male university track and field team members. Blood samples were collected before and after the exercise, and the ROS-scavenging activities (OH•, O2•−, 1O2, RO• and ROO•, and CH3•) were evaluated by the electron spin resonance (ESR) spin-trapping method. The anaerobic exercise significantly increased RO• and ROO• scavenging activities, and the total area of the radar chart in the ROS-scavenging activities increased 178% from that in pre-exercise. A significant correlation between the mean power of the anaerobic exercise and the 1O2 scavenging activity was revealed (r = 0.72, p < 0.05). The increase ratio in OH• scavenging activity after high-intensity exercise was significantly greater in the higher mean-power group compared to the lower mean-power group (n = 5, each). These results suggest that (i) the scavenging activities of some ROS are increased immediately after high-intensity anaerobic exercise, and (ii) an individual’s OH• scavenging activity responsiveness may be related to his anaerobic exercise performance. In addition, greater pre-exercise 1O2 scavenging activity might lead to the generation of higher mean power in high-intensity anaerobic exercise.
We investigated effects of molecular hydrogen (H
) supplementation on acid-base status, pulmonary gas exchange responses, and local muscle oxygenation during incremental exercise. Eighteen healthy, ...trained subjects in a randomized, double-blind, crossover design received H
-rich calcium powder (HCP) (1500 mg/day, containing 2.544 µg/day of H
) or H
-depleted placebo (1500 mg/day) for three consecutive days. They performed cycling incremental exercise starting at 20-watt work rate, increasing by 20 watts/2 min until exhaustion. Breath-by-breath pulmonary ventilation (V˙
) and CO
output (V˙CO
) were measured and muscle deoxygenation (deoxyHb + Mb) was determined via time-resolved near-infrared spectroscopy in the
(VL) and
(RF). Blood gases' pH, lactate, and bicarbonate (HCO
) concentrations were measured at rest and 120-, 200-, and 240-watt work rates. At rest, the HCP group had significantly lower V˙
, V˙CO
, and higher HCO
, partial pressures of CO
(PCO
) versus placebo. During exercise, a significant pH decrease and greater HCO
continued until 240-watt workload in HCP. The V˙
was significantly lower in HCP versus placebo, but HCP did not affect the gas exchange status of V˙CO
or oxygen uptake (V˙O
). HCP increased absolute values of deoxyHb + Mb at the RF but not VL. Thus, HCP-induced hypoventilation would lead to lower pH and secondarily impaired balance between O
delivery and utilization in the local RF during exercise, suggesting that HCP supplementation, which increases the at-rest antioxidant potential, affects the lower ventilation and pH status during incremental exercise. HPC induced a significantly lower O
delivery/utilization ratio in the RF but not the VL, which may be because these regions possess inherently different vascular/metabolic control properties, perhaps related to fiber-type composition.
Ground golf is a popular sport among the elderly in Japan. Several types of exercise can reduce the body's mean arterial pressure (MAP), but little is known about how ground golf affects the MAP. We ...investigated the effects of ground golf on the MAP and the oxygen uptake (Formula: see text) in a healthy elderly population.
Thirteen elderly Japanese people (3 males and 10 females, mean age of 66 years) participated. All participants played 8 holes of ground golf 6 times, as game (G)1 to G6. The MAP, heart rate (HR), and Formula: see text were measured at rest and every 5 min during each game.
A linear trend analysis revealed that participants' MAP values progressively decreased as each game proceeded with marginal differences (p = 0.054). There were no significant differences in HR between at rest and any of the games. The Formula: see text during the games (except for G6) were significantly higher than that at-rest (p < 0.05). The resting MAP values were negatively associated with the ground golf-induced changes in MAP (r = 0.786, p = 0.001). The participants with greater changes in Formula: see text during the games showed significantly greater reductions in MAP (r = 0.276, p = 0.043).
Playing ground golf reduced the participants' MAP and increased their Formula: see text. Participants with higher resting MAP experienced greater reductions in MAP by playing ground golf, which suggests that ground golf can be a useful recreational sport for the elderly.
This research examined the effects of single-dose molecular hydrogen (H2) supplements on acid-base status and local muscle deoxygenation during rest, high-intensity intermittent training (HIIT) ...performance, and recovery. Ten healthy, trained subjects in a randomized, double-blind, crossover design received H2-rich calcium powder (HCP) (1500 mg, containing 2.544 μg of H2) or H2-depleted placebo (1500 mg) supplements 1 h pre-exercise. They performed six bouts of 7 s all-out pedaling (HIIT) at 7.5% of body weight separated by 40 s pedaling intervals, followed by a recovery period. Blood gases’ pH, PCO2, and HCO3− concentrations were measured at rest. Muscle deoxygenation (deoxyHb + Mb) and tissue O2 saturation (StO2) were determined via time-resolved near-infrared spectroscopy in the vastus lateralis (VL) and rectus femoris (RF) muscles from rest to recovery. At rest, the HCP group had significantly higher PCO2 and HCO3− concentrations and a slight tendency toward acidosis. During exercise, the first HIIT bout’s peak power was significantly higher in HCP (839 ± 112 W) vs. Placebo (816 ± 108 W, p = 0.001), and HCP had a notable effect on significantly increased deoxyHb + Mb concentration during HIIT exercise, despite no differences in heart rate response. The HCP group showed significantly greater O2 extraction in VL and microvascular (Hb) volume in RF during HIIT exercise. The HIIT exercise provided significantly improved blood flow and muscle reoxygenation rates in both the RF and VL during passive recovery compared to rest in all groups. The HCP supplement might exert ergogenic effects on high-intensity exercise and prove advantageous for improving anaerobic HIIT exercise performance.
Accurate assessments of a target population's energy intake (EI) are essential to prevent poor nutritional status. However, self-reported dietary records (DRs) or food frequency questionnaires (FFQs) ...are not always accurate, thereby requiring validation and calibration studies. This study aimed to validate the EI estimated by a FFQ using the doubly labeled water (DLW) method. Participants were 109 Japanese older adults (50 women and 59 men) aged 65-88 years. The EI was obtained by a DR and 47-item FFQ over 1 year. The total energy expenditure (TEE) was measured by DLW for ~2 weeks. EI was significantly lower than TEE (
< 0.01); ratios of EI assessed by DR and FFQ against TEE were 0.91 ± 0.17 and 0.82 ± 0.22, respectively. TEE was significantly and moderately correlated with the EI estimated by the DR (
= 0.45,
< 0.01) and FFQ (
= 0.37,
< 0.01). Furthermore, the EI correlation coefficients estimated by DR and the FFQ in this study were not significantly different (
= 0.46). The EI/TEE ratio was significantly and negatively correlated with the body mass index (BMI). In conclusion, EI estimated with a DR or FFQ modestly correlated with TEE, and calibrating EI with a developed equation in this study can attenuate the underestimation of EI.
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