ABSTRACT
Sedentary behavior is ubiquitous in modern lifestyles and defined as any waking behavior with an energy expenditure of ≤ 1.5 metabolic equivalents while sitting, reclining, or lying. Epidemiological evidence suggests that high volumes of sedentary behavior are independently associated with an elevated risk of cardiometabolic disease and all-cause mortality. By contrast, a growing body of experimental evidence showing the potential benefits for cardiometabolic risks of reducing and breaking up sedentary time. Therefore, recent physical activity guidelines indicate the importance of reducing and regularly interrupting prolonged sitting. In this narrative review, we summarize the findings from experimental studies that investigated the acute impacts of prolonged, uninterrupted sitting and interrupting sitting on several cardiometabolic risk factors, including vascular function, blood pressure, and glucose metabolism. Here, we highlight experimental evidence from controlled laboratory trials that may lead to a better understanding of biological plausibility, the causal structure of relationships, and potential mechanistic insight on linking sedentary behavior with adverse cardiometabolic outcomes. Our literature review collectively suggests that in addition to increasing moderate- to vigorous-intensity physical activity, reducing sedentary time may contribute to cardiometabolic health. However, the recent evidence remains limited and inconclusive, thus future studies are needed to develop a deeper causal and mechanistic understanding of the biological pathways through which prolonged sitting can adversely influence cardiometabolic health outcomes.
ABSTRACT
Premenstrual syndrome (PMS) that occur during late luteal phase is a problem for many female athletes. Many studies reported that subjective condition is affected by PMS in female athletes. Moreover, female athletes with PMS have higher stress and/or anxiety levels during luteal phase compared with non-PMS athletes. However, the relationship between PMS and physical performance in female athletes are not clarified yet. The purpose of this study was to investigate the relationship between premenstrual syndrome (PMS) and jump performance in female track and field athletes. Sixteen participants who has natural basal body temperature pattern with the menstrual cycle (observed low-temperature and high-temperature phase), were participated in this study. PMS was assessed by ACOG’s premenstrual syndrome questionnaire. As physical performance, counter movement jump (CMJ) and rebound jump (RJ) were evaluated in low-temperature phase and high-temperature phase. The result of this study, no significant differences were observed in body composition and physical performance between low-temperature phase and high-temperature phase. However, compared with participants who had non-symptom, participants who had a breast tenderness of PMS showed larger decreases in jump height of CMJ (p = 0.038) and RJ index (p = 0.015) in high-temperature phase. Therefore, PMS may have a negative effect on physical performance during high-temperature phase in female athletes.
ABSTRACT
Arterial stiffness in endurance athletes is low, whereas arterial stiffness in strength athletes is high. The adaptation of the arterial stiffness may be different depending on the training type. On the other hand, there are mixed-trained athletes that can’t be classified as endurance- or strength- trained athletes. The aim of this study was to investigate the arterial stiffness among mixed-trained athletes. The total of 51 young male athletes (15 long-distance runners, 10 handball players and 26 kendo players) and 16 young healthy sedentary individuals (control group) participated in this study. Carotid-femoral pulse wave velocity (cfPWV), carotid-brachial PWV (cbPWV) and femoral-ankle PWV (faPWV), were measured as indices of central and peripheral (upper and lower limbs) arterial stiffness, respectively. cfPWV showed significantly lower in long-distance runners (high endurance capacity) and handball players (strength and high endurance capacities) compared with kendo players (strength and low endurance capacities) and control groups (P < 0.05 for both). cbPWV showed significantly lower in handball players and kendo players compared with the control group (P < 0.05 for both). There was no difference in faPWV among the groups. These data suggest that the competitive characteristics of athletes (i.e., endurance capacity or target muscle groups of sport) influence the adaptation of arterial stiffness. It can be speculated that endurance capacity in mixed-trained athletes can affect central arterial stiffness and similar to endurance trained athletes. In addition, the adaptation in upper limb arterial stiffness will be included in the training effects associated with the sports-specific target muscle groups, while lower limb arterial stiffness may not be unaffected by any type of exercise.
ABSTRACT
<p>The symptoms of anemia, decreases in the levels of circulating red blood cells (RBC), hemoglobin (Hb) and hematocrit (Ht) lead to decrease endurance performance, and the risk of anemia increases in female endurance athletes. Although Hb is composed of a large amount of amino acids, the relationships between circulating levels of amino acids and RBC, Hb and Ht in female endurance athletes have not been clarified yet. Thus, the purpose of the present study was to investigate the relationship between circulating levels of amino acids and RBC, Hb and Ht in female endurance athletes. Twenty-four female endurance athletes (19.8 ± 0.2 years) participated in this study. We measured circulating levels of RBC, Hb and Ht from blood. Also, we measured circulating levels of amino acids from plasma by use of comprehensive analysis. The levels of circulating RBC, Hb and Ht in all subjects were within the normal range. We found that circulating taurine levels were significantly correlated with RBC (r = 0.48, p < 0.05), Hb (r = 0.44, p < 0.05) and Ht (r = 0.42, p < 0.05) in female endurance athletes. In the present study, we demonstrated that circulating taurine levels were significantly associated with RBC, Hb and Ht in female endurance athletes. These results suggest that circulating taurine levels may be a predictor of anemia and treatment strategy for anemia.</p>
ABSTRACT
Strenuous and consecutive exercise results in fatigue symptoms accompanied decrease in salivary secretory immunoglobulin A (sIgA) in athletes. On the other hand, it has been reported that plasma taurine concentration was increased after the high intensity exercise. However, change in salivary taurine concentration after strenuous and consecutive exercise is unknown. The purpose of this study was to investigate the relationship between fatigue symptoms and changes in salivary taurine concentration in collegiate male soccer players. Thirty seven collegiate male soccer players participated in three consecutive days of match program. To detect of fatigued players, we measured awakening heart rate and body weight. As the results of these two measurements, we divided subjects to two groups (non-fatigue group, n=15; fatigue group, n=22). We also measured salivary sIgA and taurine concentrations before and after program. Before the program, there were no significant differences in any parameters between two groups. Salivary flow rate and sIgA secretion rate were significantly decreased after the program in the fatigue group. Furthermore, salivary taurine concentration was significantly increased after the program in the fatigue group. In the non-fatigue group, there were no significant differences in any parameters during program. Our results indicated that salivary taurine concentration increased after consecutive high-intense exercise in the collegiate male soccer players.
ABSTRACT
Obesity and increasing of arterial stiffness are known as independent risk factors for cardiovascular disease. Previously, we demonstrated that dietary modification or aerobic exercise training can decrease arterial stiffness in obese individuals. However, it has not been compared the effect of dietary modification and/or aerobic exercise training on arterial stiffness in obese men. We compared the effect of three patterns of lifestyle modification (i.e., dietary modification, aerobic exercise training or combined them) on arterial stiffness in obese men. Fifty-three obese men completed the 12-week lifestyle modification program, dietary modification (D), aerobic exercise training (E) or combined D and E (DE). Before and after the program, all participants were measured central, peripheral, and systemic arterial stiffness (measured by carotid-femoral pulse wave velocity [cfPWV], femoral-ankle PWV [faPWV] and brachial-ankle PWV [baPWV]). We demonstrated that the degree of decrease in BMI was the greatest after DE, and that was greater after D than E. The level of decrease in baPWV after DE was the greatest among three interventions. On the other hand, the level of decrease in baPWV in D group was similar to E group. These results suggested that systemic arterial stiffness may be decreased by different mechanisms between D and E groups. We demonstrated that dietary modification decreased central and systemic arterial stiffness, and aerobic exercise training decreased central, systemic, and peripheral arterial stiffness in obese individuals. We also showed an additional effect of decreasing systemic arterial stiffness by combining dietary modification and aerobic exercise training in obese individuals.
ABSTRACT
<b>Objective:</b> Aerobic exercise on land decreases arterial stiffness, however, the effect of exercise in water on arterial stiffness has not been clear. This study investigated the effect of a 15-min cycling exercise on land and that in water on pulse wave velocity (PWV) as an index of arterial stiffness. <b>Methods:</b> Nine healthy young men were randomly performed exercise on land and exercise in water equivalent to 50% of each maximum oxygen uptake on separate days. The PWV from carotid to femoral artery (aortic PWV) and femoral to posterior tibial artery (leg PWV) were measured at baseline and 15, 30, 60 min after exercise. <b>Results:</b> The heart rate in water was significantly lower during exercise than that on land. In addition, the carbon dioxide output and respiratory exchange ratio during exercise were significantly greater in water. Body temperature increased after the exercise on land but decreased after the exercise in water. Although the aortic PWV and leg PWV decreased concomitantly with decrease in SBP and DBP after the exercise on land, there were no significant changes after the exercise in water. <b>Conclusion:</b> Although acute exercise on land decreased arterial stiffness after exercise, acute exercise in water of the same exercise load did not. The differences in body temperature and blood pressure after exercise may result in diverse arterial stiffness after exercise.
ABSTRACT
The purpose of this study was to investigate the interaction of habitual exercise and candidate gene polymorphisms related to bone on osteo sono-assessment index (OSI) by quantitative ultrasound (QUS) in middle-aged and elderly Japanese. Participants were classified into exercise group (E; n=172, 62.3 ± 7.7 yr) and sedentary group (S; n=65, 58.6 ± 9.2 yr). The OSI was measured with AOS-100. DNA was extracted from blood, and single nucleotide polymorphism in vitamin D receptor, estrogen receptor α, and transforming growth factor-βI were genotyped by TaqMan assay. Group E had significantly lower body weight and body mass index (BMI) than Group S. In men, although Group E was older than Group S, Group E had significantly higher OSI rather than Group S. There was no significant interaction between habitual exercise and each gene polymorphism on OSI. These results essentially remained unchanged even when analysis of covariance was applied after adjustment for age, body weight, and BMI. These results suggest habitual exercise and genetic factors have no interaction on OSI in middle-aged and elderly Japanese. Further investigations are needed to prove the interaction of other gene polymorphisms and exercise.
ABSTRACT
High-sensitivity C-reactive protein (CRP) is a novel risk factor for coronary artery disease. It is well known that body weight loss is effective in reducing serum CRP concentration ; however, the effect of exercise training on serum CRP concentration has not been fully elucidated. The purpose of this study was to examine the effect of a 24-week exercise training program on serum CRP concentration in 169 healthy middle-aged and elderly subjects (65.9±6.4 years). Each subject underwent baseline testing (peak oxygen uptake, daily physical activity, body weight, and serum CRP levels), and repeated these tests on completion of the training program. The subjects were classified into 2 groups based on initial CRP levels : normal<1.0 mg/L, n=139, and high≥1.0mg/L, n=30. On completion of the program, both daily physical activity and peak oxygen uptake increased significantly (+33.9±72.4%, p<0.0001, +5.4±14.7%, p=0.014, respectively). However, body weight did not change significantly. In addition, CRP levels of the entire group did not change significantly. However, CRP levels significantly decreased among the high baseline CRP group (from 1.82±0.81 mg/L to 0.98±0.59 mg/L, p<0.0001). It was concluded that serum CRP levels are reduced without body weight loss in response to exercise training in healthy middle-aged and elderly subjects with high initial CRP levels.
ABSTRACT
Skeletal muscle is comprised of multiple fiber types. Slow-twitch oxidative muscle fibers have greater capillary density compared with fast-twitch glycolytic fibers of skeletal muscle. To gain insight into the molecular mechanism underlying the difference of capillary density, we investigated whether the basal gene expression of vascular endothelial growth factor (VEGF), a major angiogenesis-related factor, and its transcriptional factors (hypoxia-inducible factor-1α, transforming growth factor-β1, c-jun, and c-fos) differs between these two fiber types of rat skeletal muscle. The mRNA expression of VEGF and its transcriptional factors was significantly higher in slow type fiber of muscle (soleus muscle) compared with fast type fiber of muscle (plantaris and tibialis anterior muscles). These results suggest that the difference of basal gene expression of VEGF and its transcriptional factors between slow and fast fiber types of skeletal muscle may partly contribute to the difference in capillary density between these two fiber types.
ABSTRACT
The engaging>30 minutes of physical activity (PA) at 4-6 METs has been recommended for the prevention of cardiovascular disease. We determined whether relatively low intensity (i. e., 3-5 METs) PA inhibits the age-related central arterial stiffening, a risk of cardiovascular disease. In the cross-sectional study, the association between carotid arterial properties (via ultrasound system) and daily PA (via electric accelerometer) were studied in 172 normotensive people (41-82 yrs). People engaging>30 min/day of PA corresponding to 3-5 METs had a significantly lower beta-stiffness index than sedentary peers after adjusting for covariates (i. e., age and PA time at more than 6 METs). In the interventional study, beta-stiffness index of nine normotensive postmenopausal women was significantly decreased after the 12-week aerobic training (cycling at 80% of ventiratory threshold, ≈4 METs, 30 min/day, 5 days/week). These results suggest that the increase in daily PA at 3-5 METs inhibits the age-related carotid arterial stiffening.
ABSTRACT
To investigate a relationship between gender differences in recovery from skeletal muscle fatigue and muscle oxygenation, we examined whether there is a difference in oxygen supply and consumption of the working muscles after intermittent handgrip exercise between young males and females using near-infrared spectroscopy (NIRS). Healthy young subjects (25.8±3.9 years ; males, n=10 ; females, n=10) repeated static maximal voluntary contractions (MVC) with a handgrip for 5 seconds followed by 5 seconds rest for a period of 4 minutes in Study 1. The MVC force was measured before, each minute during the handgrip exercise, and 2, 5, and 10 minutes following the exercise. In Study 2, the selected 10 subjects (males, n=5 ; females, n=5) performed the same exercise and their total- and deoxy- hemoglobin/myoglobin level was measured using the venous occlusion NIRS method; and O<sub>2</sub> supply index (OSI) and O<sub>2</sub> consumption index (OCI) calculated before and after the exercise. In Study 1, females exhibited higher %MVC force at the end of the exercise and during the recovery period than males (p<0.05). In Study 2, the %OSI was significantly lower in females than in males at 5 and 10 minutes in the recovery period (p<0.05), but no significant differences were detected in %OCI. Furthermore, %MVC of the recovery period correlated with %OCI of the recovery period in females (r=0.724, p=0.015), but not in males. These findings suggest that female working muscles can convert consumed oxygen more effectively after an intermittent handgrip exercise, and therefore, be able to recover muscle force faster.
ABSTRACT
The purpose of this research was to study the effects of exercise program participation on the personal factors of exercise adherence promotion in the middle-aged and elderly by comparing a group and individual exercise program. The personal factors for promoting exercise adherence, the four domains (i, e. initiative attitude, achievement satisfaction, self-recognition, and intrinsic motivation), were hypothesized. Two groups of middle-aged and elderly subjects, who volunteered to participate in different 6-month exercise programs, were examined. Group 1, 33 subjects (aged 67.7 ±4.3 years : mean±SD), participated in a program consisting of an individual exercise program (combination of endurance and resistance exercise, e. g. cycling exercise, dumbbell and machine exercise, once a week) and group exercise program (e, g. dance and ball game, once a week) . Group 2, 27 subjects (aged 65.2±4.Ovears), participated in the same individual exercise program twice a week. After the 6-month exercise program, significant improvements in group 1 were found in the selfassessment of activity score of the initiative attitude domain, the achievement satisfaction score including enjoyment, achievement and satisfaction, and the self-recognition score representing competence. In group 2, the mastery score in the intrinsic motivation domain was reduced, and the curiosity score in the same domain and the achievement score in the achievement satisfaction domain tended to decrease. These results show that a group program might have a more significant effect on the personal factors hypothesized to promote exercise adherence in this study. Hut there should be follow-up study on the subjects to determine the effectiveness of the program over the long term.
ABSTRACT
Arterial compliance progressively decreases with aging. This aging-induced reduction of arterial compliance causes an increase of systolic blood pressure (SBP), whereas regular exercise increases arterial compliance. We hypothesized that an increase in daily physical activity (DPA) produces a beneficial effect on systemic arterial compliance (SAC ; an index of central arterial compliance) and this phenomenon could decrease SBP in the elderly. We investigated the relationship among DPA, SAC, SBP, diastolic blood pressure (DBP), and some other risk factors for cardiovascular and/or cerebrovascular events (total cholesterol, HDL-cholesterol, and HOMA-R) cross-sectionally in 127 elderly persons (42 male, 85 female : aged 74±4 years) . The DPA was estimated by expended calories using an accelerometer. The SAC was calculated from a finger pulse pressure waveform recorded by using PORTAPRES ; and stroke volume obtained from the same pressure waveform based on the volume-clump method. The analyses demonstrated that SBP was directly and decreasingly affected by SAC, and that DPA had an increasing effect on SAC. Furthermore, SBP was directly and increasingly affected by DBP, and DBP was directly and decreasingly affected by both SAC and DPA. Therefore, it is considered that DPA may have suppressive effects on the rise of SBP through the indirect effects of changing SAC and DBP. These findings suggest that an increase in DPA could improve the age-induced reduction of arterial compliance and rise of SBP in elderly humans.
ABSTRACT
The effects of endurance training and detraining on cardiac autonomic nervous system activity were studied by using the power spectral analysis of heart rate (HR) variability. Twenty-one sedentary male subjects were trained for 8 weeks using cycle ergometer exercise [70% of maximal oxygen uptake (VO<SUB>2</SUB>max), 60 min, 3.4 times/wk] . Resting HR for 5 min was recorded before the training, after the 8-week training period, and after the 2-week and 4-week detraining period. The indices of cardiac parasympathetic and sympathetic nervous system activity were determined by Mem-Calc method, as the high frequency power (HF : 0.15-0.50 Hz) and the ratio of the low frequency power (LF : 0.04-0.15 Hz) to the HF (LF/HF), respectively. The VO<SUB>2</SUB>max after the training and 4 weeks detraining period were significantly higher than the initial value (before training : 41 ± 1 ml/kg/min ; after training: 48±2, <I>P</I><0.0001; after detraining: 46±2, <I>P</I><0.001) . The HF was significantly in-creased by the training (<I>P</I><0.05), and maintained the increased level for the 2-week detraining period (before training : 6.4±0.3 In ms<SUP>2</SUP>; after training: 7.0±0.2, <I>P</I><0.01; after 2-week detrain-ing: 7.0±0.2, <I>P</I><0.05) . The increase in the HF, however, disappeared after the 4-week detraining period (6.8±0.31n ms<SUP>2</SUP>) . The LF/HF did not show any significant changes during the training and detraining period. These results suggest that an endurance exercise with moderate intensity enhan-ces cardiac parasympathetic nervous system activity, but not cardiac sympathetic nervous system activity. The enhanced cardiac parasympathetic nervous system activity, however, may regress rapidly during detraining period.
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It is generally accepted that visually impaired individuals generally have a low aerobic capacity, which may be partly attributed to a lack of physical activity, and have hypothesized that their response to exercise may differ from that of normal-sighted people. In this study, we investigated the effect of exercise on local immunity in the oral cavity in 24 visually impaired males (n=8 ; totally blind group, n=16 ; partially sighted group) and 8 normal-sighted males. The subjects performed submaximal graded bicycle ergometer exercise to an intensity of 75% heart rate max for 12 min. Before and immediately after exercise, we collected timed saliva samples and measured secretory immunoglobulin A (sIgA) .<BR>The totally blind group had lower levels of aerobic capacity and a lower sIgA secretion rate compared to the partially sighted and sighted groups. Immediately after exercise, the sIgA secretion rate tended to increase in the totally blind group.<BR>It is suggested that the exercise-induced response of local immunity in the totally blind group differed from that in the other groups.
ABSTRACT
Although it has been established that exercise is useful for health promotion, physical exercise may induce oxidative stress in humans. Our previous study showed that the concentration of plasma protein-bound sulfhydryl groups (p-SHs) was significantly decreased after strenuous exercise, i. e. full-marathon running and participation in an athletic training camp. Reactive oxygen species may cause oxidation of plasma proteins <I>in vitro</I>. To study whether moderate exercise for health promotion, e. g. jogging or walking, induces oxidative stress in human circulating blood, the authors examined the change in plasma p-SHs concentration following ergometric exercise at moderate intensity and of relatively short duration {Exercise 1: 80% ventilatory threshold (VT), 100% VT, and 110% VT; 30 min, Exercise 2 : 90% VT; 120 min} in 8 (23-28 yr; Exercise 1) and 6 males (23-28 yr; Exercise 2) respectively. The plasma p-SHs concentration did not changed significantly after Exercise 1 or 2. The data indicated that the exercise did not cause significant modification of plasma proteins, suggesting that it did not induce significant oxidative stress in the circulating blood.
ABSTRACT
A study was carried out to examine the effects of water replacement on cardiovascular function during kendo practice in a hot environment. Five male college kendoists performed moderately severe 30-min kendo practice at a WBGT index of about 27°C with and without water intake. For water replacement, the subjects ingested 700 ml water (500 ml before exercise and 200 ml at 15 min after the start of exercise) . Under both conditions, body weight was decreased significantly, and hematocrit and serum total protein concentration were increased significantly after the exercise. With water replacement, the body weight loss induced by the exercise was similar to that under water deprivation. However, the decrease in body weight from the basal body weight, i. e. body weight measured before water intake, was significantly less with water replacement than under water deprivation. There were no significant differences in the percentage increases of hematocrit and serum total protein concentration between the two conditions, although the percentage change in plasma vasopressin concentration was significantly lower with water replacement than without. In the subjects deprived of water, the left ventricular end-diastolic dimension and left atrial dimension were significantly reduced after the exercise, and stroke volume, ejection fraction, and fractional shortening were also decreased significantly. The ratio of left ventricular end-systolic wall stress to left ventricular end-systolic volume index was increased significantly after the exercise without water intake. With water replacement, however, the percentage decreases in cardiac dimensions, stroke volume, ejection fraction, and fractional shortening were significantly lower than those under water deprivation. There was no significant change in the ratio of left ventricular end-systolic wall stress to left ventricular end-systolic volume index before and after the exercise with water intake. It is suggested that 700 ml water replacement before and during kendo exercise in a hot environment prevents depletion of stroke volume and deterioration of cardiovascular function, although it might not improve significantly the plasma volume loss after exercise.