ABSTRACT
Although there are a number of reported cases of increased cerebral blood flow during exercise, there are no reports on the relation between changes of blood flow during exercise and attentional function. The purpose of this study is to clarify the relation between changes of blood flow during exercise with AT intensity and attentional function, using near-infrared spectral analysis. The subjects were 10 healthy males. The research protocol was to conduct steady load exercise. We randomly conducted two invention trials: 1) an exercise/task trial in which a trail making test (TMT) was performed as an attentional assignment during steady load exercise, and 2) a rest/task trial in which TMT was performed during rest as a control. As a result, we observed the following: increase of oxy-Hb in the prefrontal cortex during AT exercise, the significant shortening of TMT during exercise from 69.1±10.2 seconds to63.2±7.2seconds, and, with further control, that the more oxy-Hb rises, the more TMT time is shortened. From these results, it is suggested that 10 minutes of exercise would improve attentional function, and furthermore, there is a possibility that increased cerebral blood flow may be involved with the improvement of attentional function.
ABSTRACT
The aim of the present study was to examine whether amount of oral cortisol, immunoglobulin A (IgA), chromogranin A (CgA) and inflammatory cytokines, might be affected by prolonged strenuous exercise. Ten young male volunteers either exercised on recumbent ergometer at 75 % VO<sub>2</sub> max for 60 min (exercise session) or sat quietly (resting session). Saliva samples were obtained at 60 min intervals during sessions for measurements of salivary stress markers (cortisol, IgA and CgA), salivary inflammatory cytokines, such as interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) and osmolality. Saliva flow rate was decreased and saliva osmolality was increased during the 60-min exercise. Saliva cortisol and CgA concentrations and secretion rates were increased during and after the exercise, whereas saliva IgA concentration and secretion rates were decreased after the exercise. Salivary inflammatory cytokines was increased during and after the exercise. The present findings suggested a single bout of prolonged strenuous exercise caused a transient increase in the salivary cortisol, CgA and inflammatory cytokines levels, whereas salivary IgA concentration and secretion rates were decreased after the exercise. Further studies, however, are needed to delineate whether or not salivary stress markers and inflammatory cytokines may be used as biological markers to determine the host responses to acute prolonged strenuous exercise.
ABSTRACT
The purpose of this study was to examine the effects of aquatic exercise training on the trunk muscles function and activities of daily living in abdominal obese women. Nineteen abdominal obese (abdominal circumference: 90 cm or more) and fifteen age-matched non-obese women were recruited as participants in this study. The aquatic exercise training (60 min/day, three days/week for 8 weeks) based on abdominal twists for activating the trunk muscle function. Physical parameters, biochemical characteristics, arteriosclerotic parameters and activities of daily living scores were assessed before and after the training period. In both groups showed abdominal circumference, percent of body fat, blood pressure and lower extremity muscle strength increased significantly after aquatic exercising training. In particular, endurance capacity of abdominal and back muscles increased significantly and activities of daily living scores were significantly improved in the obese group. Moreover, the improvement in the strength of lower extremities and improvement in the activities of daily living scores, such as climbing and descending stairs, in the obese group tended to be higher than non-obese women. Additionally, in abdominal obese group, the amount of the reduction of abdominal circumference was significantly associated with that of the increase in the strength of lower extremities. Taken together, these findings suggest the possibilities that the present aquatic exercise training based on trunk muscle exercise improving the function of trunk and lower extremity muscles with reduction in the abdominal obesity, contributing to improve activities of daily living in abdominal obese women.
ABSTRACT
The decrease of balance capacity is considered as a high risk factor of fall accident, so it is important for the middle-aged and elderly people to keep balance capacity on a high level. In this study, we investigated the effects of aqua exercise on dynamic and static balance function. Thirty-two middle-aged women (56.6±8.1 years) participated a 60-min aqua exercise program three times per week for eight weeks. After exercise intervention, body weight, body mass index, grip strength, side step, shuttle stamina walking test were significantly improved (p<0.05-0.001). Functional reach (p<0.001) and total length of centroid shake with eye close condition (p<0.05) was significantly improved, but with eye open condition was not changed. However, when we evaluate the total length of centroid shake by T-score, static balance performance with eye open and close condition was significantly (p<0.05) improved in the below average groups. In addition, measurement value of functional reach was also improved in these groups. These results indicate that aqua exercise benefits not only physical muscle strength and endurance capacity, but also balance function in middle-aged women. Particularly aqua exercise is more effective for the subjects with lower static balance function before intervention.
ABSTRACT
The usage of “Taiji sense”(a kind of image) is required during Taijiquan (TJQ) exercise, but some practitioners virtually ignore it all the time while exercising. The significance for the usage of “Taiji sense” is still completely unknown. This study assessed the psycho-physiological effects of “Taiji sense” during 24-style TJQ exercise (24TJQ). 25 middle-elderly 24TJQ-experienced subjects were divided into Taiji-sensed group (TS), non-Taiji-sensed group (NTS) and ergometry exercise group (EE) by balancing their age and TJQ experience time. The division of TS and NTS was determined by a self-reported investigation, based on whether the practitioner usually use or do not use the image of “Taiji sense” while exercising TJQ. Electroencephalography and profile of mood states were examined and compared. After exercise, TS showed greater increase of α activity (P<0.05) and greater decrease of β activity (P<0.05) than EE, respectively. α hemispherical asymmetry score indicated by Fp1-Fp2 showed significant decrease change (P<0.05) in TS after exercise (Post2), and tended to be lower (P=0.056) than that of NTS. Even though all conditions significantly decreased Tension-Anxiety (T-A) scores (P<0.05, for all), only TS significantly increased Vigor (V) score (P<0.05). The change of α activity inversely correlated to the change of T-A score (r=−0.78, P<0.0001) in all conditions. Conclusively, the usage of “Taiji sense” might help to produce stronger psycho-physiological responses during 24TJQ practice, and give rise to effective relaxation after exercise, as classics pointed out.
ABSTRACT
We investigated the relationship between body weight reduction and intensity of daily physical activities assessed with 3-dimensional accelerometer during a 3-month exercise program. Twenty-six middle-aged women (58.1±7.4 yrs.) participated in this study. Participants underwent a 90-min endurance exercise intervention once a week, and a 3-dimensionsal accelerometer was attached through the program. Body weight (BW), body mass index, fat mass and percent body fat were reduced significantly (p<0.001), while diastolic blood pressure (p<0.01) and shuttle stamina walking test (p<0.05) improved significantly after the exercise intervention. Moreover, a significant negative correlation was observed between the changes in BW and total activity time (TAT) per day of more than 3METs (TAT≥3METs)(r=−0.580, p<0.01) and TAT≥4METs (r=−0.627, p<0.001). To the contrary, the daily steps and the TAT≥2METs were not related to the changes in BW. After adjusting daily steps, TAT≥3METs (β=−0.630, p<0.01) and TAT≥4METs (β=−0.659, p<0.01) were still significantly related to the changes in BW. These results indicate that weight reduction has a much closer relationship with exercise intensity than daily steps. It is important to keep both quantity and intensity of exercise in the unsupervised exercise program aimed at weight reduction.
ABSTRACT
The purpose of this study was to investigate the effect of constant endurance cycling exercise below Ventilatory Threshold (VT), under different pedal rate/torque regulations (PTR), on muscle oxygenation, as well as cardio-respiratory function and energy metabolism. Eight healthy male adults participated in the study for three tests. The first test was to examine the maximum oxygen uptake (VO<sub>2</sub>max) using a ramp loading measurement of 60 rpm, 20 watt/min ; and an individual 80%VT load was obtained. The second and third tests (random) were to measure heart rate (HR), blood pressure (MAP), expired gas and NIRS data before, during and after 30 min 80%VT constant cycling exercise with low pedal rate/high torque (LPHT : 32 rpm, 23.3±6.0Nm) or high pedal rate/low torque (HPLT : 79rpm, 9.4±2.4Nm). As a result, HPLT showed higher values in HR (p<0.001), MAP (p<0.001), VO<sub>2</sub> (p<0.001), VCO<sub>2</sub> (p<0.001) and RER (p<0.05), than LPHT ; but LPHT showed a higher fat consumption rate than HPLT (p<0.05). Significant PTR effect were recognized for the parameters of the tissue hemoglobin index (THI) (p<0.001) and oxygenation hemoglobin (ΔO<sub>2</sub>Hb) (p<0.01) ; and both indicated higher values for HPLT than LPHT ; but LPHT showed insignificantly (p=0.066) higher de-oxygenation hemoglobin (ΔHHb) than HPLT. Moreover, the significant time effects of THI and ΔO<sub>2</sub>Hb were also recognized. In conclusion, this study indicated that during constant cycling exercise below VT, HPLT might result in greater muscle blood volume, higher muscle oxygenation concentration and higher HR and VO<sub>2</sub> compared with LPHT. These results suggest that, HPLT might be effective in alleviating the working load on lower limbs, as well as promoting muscle oxygenation, cardiorespiratory function (systemic oxygen supply) and energy metabolism. Therefore, HPLT constant cycling exercise below VT could be used in a rehabilitation program as a beneficial exercise for elderly people with decreasing muscle strength in their lower limbs.
ABSTRACT
The purpose of this study was to confirm both the reproducibility of indices (NIRS slope, NT2, %NIRS fall) and the specificity obtained by analyzing the muscle oxygenation curve measured by near-infrared spectroscopy (NIRS) during ramp exercise. Ten healthy men participated in this study. The NIRS probe was placed on the vastus lateralis muscle. An increase in oxygenation was observed from rest to warm-up at 0 watts (Δ NIRS) . Oxygenation began to decrease lineally as the workload increased (NIRS slope) . In the latter phase of exercise, the oxygenation curve flattened out despite an increasing workload, and as a result, an inflection point was formed (NT2) . The minimum value of oxygenation during ramp exercise was indicated as“%NIRS fall.”<BR>Protocol 1. After a warm-up period of 3 min at 0 watts, a ramp exercise (20 watt/min) test was performed until volitional fatigue. The test was performed for each subject twice (test-1, test-2) with a 1-week interval. Protocol 2. A test was performed with three consecutive ramp exercises (lOwatt/min·20watt/min·30watt/min) up to120watt each with sufficient rest between the exercises.<BR>NT2 was observed in 7 of 10 subjects. Test-1 and test-2 mean values of ANIRS, NIRS slope, watts at NT2 (NT2) and %NIRS fall were not significantly different, and the correlations between test-1 and test-2 were highly significant (r=0.94, P<0.0001: ANIRS, r=0.99, P<0.0001: NIRS slope, r=0.91, P<0.002: NT2 and r=0.78, P<0.005 : %NIRS fall) . The regression lines obtained for correlations of results of test-1 and test-2 were y=-5.89+1.38X (Δ NIRS), y=0.02+ 1.03X (NIRS slope), y=31.52+0.83X (NT2), and y=19.91+0.61X (%NIRS fall) . No significant differences in both intercept and coefficient between the regression line and identity line were found in the NIRS slope and NT2. The rate of decrease in the oxygenation curve became steeper with an increase in work-load from 10 watts/min to 20 watts/min and to 30 watts/min. However, the mean values of the NIRS slope, modified by watts, were 0.29±0.06%/watt, 0.29±0.07%/watt and 0.29±0.07%/watt, respectively. There were no significant differences of the NIRS slopes among these exercises. The results indicate constancy of the rate of decrease in oxygenation per workload.<BR>In conclusion, these findings demonstrate the reproducibility of the NIRS slope and the appearance of NT2 during ramp exercise, and the specific way in which the decrease in muscle oxygenation reflects workload. They suggest that analysis of the muscle oxygenation curve can be used to estimate muscular metabolism and indices of training effects.
ABSTRACT
A study was conducted to establish a method for quantitative evaluation of both the rate and degree of muscle oxygenation during ramp exercise using Near Infrared Spectroscopy (NIRS), and to determine the relationship of the indices to body composition and physical fitness. The subjects were 13 healthy men. After a warm-up period of 3 min at 20-W, the ramp exercise test was conducted. The exercise consisted of an increasing work rate at a slope of 20 W/min on a cycle ergometer performed until volitional fatigue. The NIRS probe used in the cycling exercise was placed on the vastus lateralis muscle. After 30 min of exercise, calibration was performed by cuff occlusion for 10 min with a pressure of 260 mmHg for quantitative determination of the NIRS curve. The oxygenation curve measured by NIRS during the exercise initially exhibited a linear decrease as the work rate increased. This rate of decrease in oxygenation was indicated by the NIRS slope (%/W) obtained from the calibration curve. In later stages of the exercise, the NIRS curve became flattened with increased work rate. The breaking point between the sloping phase and the flat phase was named the “NIRS Threshold 2, NT 2”. In addition, the rate of decrease in oxygenation at the end of exercise per maximal NIRS decrease obtained from the calibration curve was indicated as the %NIRS fall. The mean NIRS slope and %NIRS fall were 0.3±0.1%/W (range, 0.13 to 0.50%/W) and 29.9±11.8% (range, 12.0 to 50.0%), respectively. NT 2 was observed in 8 of the 13 subjects. The subjects were divided into two groups (NT 2 (+) and NT 2 (-) ) based on the appearance of NT 2. Both the NIRS slope and %NIRS fall in the NT 2 (+) group were significantly higher than those in the NT 2 (-) group. The NIRS slope was significantly correlated with VO<SUB>2</SUB>/wt at VT (r=0.73, p<0.05) and wattage at VT (r=0.86, p<0.0001) . The %NIRS fall was significantly correlated with VO<SUB>2</SUB>/wt at peak (r=0.80, P<0.001) . The NIRS slope and %NIRS fall were not significantly correlated with body mass index, %fat or thigh circumference.<BR>These findings suggest that the NIRS slope indicates the efficiency of oxygen exchange in muscles activated during incremental exercise, and that the %NIRS fall indicates the ability to utilize Oxy-Hb+Mb against maximal oxygenation capacity in muscles. The NIRS slope and %NIRS fall can therefore be used as indices of muscular limitation during exercise, and as indices of muscular adaptation during exercise.
ABSTRACT
A study was performed to clarify the effects of endurance training above the anaerobic threshold (AT) on the isocapnic buffering phase during incremental exercise in athletes. Eight middle-distance runners aged 19.6±1.2 years performed incremental exercise testing with a modified version of Bruce's protocol. After a 6-month high-intensity interval and paced running training at levels above AT, maximal oxygen uptake (VO<SUB>2</SUB>max) (ml⋅ kg<SUP>-1</SUP>⋅min<SUP>-1</SUP>) was significantly increased from 60.1±5.7 to 64.7±5.5 (p<0.05) . AT (m⋅lkg<SUP>-1</SUP>⋅min<SUP>-1</SUP>) was slightly but significantly increased from 28.2±3.5 to 29.6±4.3 (p<0.05) . The respiratory compensation point (RC) (ml⋅ kg<SUP>-1</SUP>⋅min<SUP>-1</SUP>) was markedly increased from 53.0±8.3 to 57.7±8.2 (p<0.05) . Although neither the slope of the first regression line below AT (S1) nor that of the second line above AT (S2) calculated by V-slope analysis was altered, the range of isocapnic buffering (ml⋅kg<SUP>-1</SUP>⋅min<SUP>-1</SUP>) from AT to RC was significantly extended from 24.8±5.9 to 28.1±6.0 after the 6-months of training (p<0.05) . In addition, the amount of change in VO<SUB>2</SUB>max after the 6-month of training period (ΔVO<SUB>2</SUB>max) was correlated with Δisocapnic buffering (R=0.72, p<0.05) . We conclude that the degree of increased respiratory compensation point is larger than that of AT after high-intensity endurance training at levels above AT, and that the range of isocapnic buffering may be an important factor in relation to the increase in the maximal aerobic capacity of athletes.
ABSTRACT
A study was performed to clarify the relationships between oxygen uptake (VO<SUB>2</SUB>) kinetics on recovery from incremental maximal exercise and blood lactate, glucose and alanine metabolism. Eight healthy males aged 21.6±3.3 years were studied. The incremental exercise test was performed using a modified version of Bruce's protocol until 30 min after exhaustion. The VO<SUB>2</SUB> responses on recovery were fitted by a two-component exponential model. Blood lactate concentration in the recovery phase was fitted by a bi-exponential time function to assess the velocity constant of the slowly decreasing component (γ2) expressing the rate of blood lactate removal. Both blood lactate and plasma alanine concentration were significantly increased from rest to maximal exercise, and were significantly decreased thereafter, but remained above resting values for 30 min after the maximal stage. Blood glucose concentration was significantly decreased following maximal exercise and returned to the pre-exercise value by 30 min after the maximal stage. Concentrations of plasma branched-chain amino acids (valine, leucine and isoleucine) were significantly decreased from the maximal stage until 30 min after exhaustion. The time constant of the slow component on recovery VO<SUB>2</SUB> [τVO<SUB>2</SUB> (s) ] was correlated with neither γ2 nor the degree of change in blood lactate from the maximal stage until 30 min after exhaustion (Δlactate) . However, τVO<SUB>2</SUB> (s) was significantly correlated with both Δ blood glucose and Δ alanine. In addition, Δ alanine was significantly correlated with Δ blood glucose. From these results, we conclude that oxygen uptake kinetics after exhaustive maximal exercise is related to glucose resynthesis through alanine metabolism, as compared with that from lactate metabolism.
ABSTRACT
To clarify changes in body temperature during endurance exercise in patients with spinal cord injury (SCI), we measured tympanic temperature (Tty) and skin temperature in the head, arm, chest, thigh, shin and calf in 5 patients with SCI (T6-T 12) and 7 normal controls during 30 minutes arm cranking exercise (20 watts) from 10 minutes before the initiation of exercise until 10 minutes after the termination of exercise in an artificial climate room at a temperature of about 25°C with a relative humidity of about 50%. The Tty in the SCI group was lower than that in the control group from 10 minutes before the initiation of exercise to 10 minutes after the termination of exercise with a significant difference only at the initiation of exercise. The difference in Tty slightly decreased with continuation of exercise. The Tty in the SCI group at rest was 36.05-37.15°C. Four patients in this group showed a decrease of 0.04-0.12°C in the early stage and an increase of 0.66°C±0.19 (mean±SD) at the end of exercise over the value at the initiation of exercise.<BR>The skin temperature was lower in the SCI group than in the control group in all sites excluding the arm. Significant differences were observed in the head in the early stage of exercise and after exercise, in the chest from 10 minutes before the initiation of exercise to 5 minutes after the termination of exercise, in the thigh from 10 minutes before the initiation of exercise to 10 minutes after the termination of exercise, in the shin 10 minutes and 5 minutes before the initiation of exercise, and in the calf from before to 15 minutes after the initiation of exercise. In the SCI group, marked individual differences were observed in the skin temperatures in the thigh, shin, and calf, suggesting specificity of the skin temperature response in and near the paralysis area.<BR>Results in Tty in this study suggested no heat retention in the SCI patients. Therefore, the risk for heat disorders seems to be low during moderate or mild exercise under moderate temperature environment at a temperature of about 25°C with a relative humidity of about 50% even when the skin temperature is low, and thermolysis is not marked.
ABSTRACT
A study was conducted to clarify the influence of water immersion at different levels on pulmonary response. The subjects, ten healthy men (mean age, 26.2±7.9 years), subjected to measurement of static lung volumes and maximum expiratory flow-volume curves while sitting immersed in water at the level of both the neck and diaphragm. TLC, VC, ERV and FRC for water immersion at the diaphragm level were significantly decreased in comparison with those measured in air. These lung volumes were further decreased upon water immersion to neck level. However, RV did not change significantly upon immersion at either water level. Significant decreases of FEV<SUB>1⋅0</SUB>, FEV<SUB>1⋅0</SUB>%, V<SUB>50</SUB> and V<SUB>25</SUB> were observed upon water immersion at the diaphragm level as compared with those obtained in air. Water immersion to neck level produced further decreases in pulmonary functional parameters. Although peak flow and V<SUB>75</SUB> did not change significantly upon water immersion at either level, V<SUB>50</SUB> and V<SUB>25</SUB> were decreased markedly in comparison with the values obtained in air. A tendency for a marked decrease in pulmonary function parameters was observed upon water immersion to neck level. The changes observed upon water immersion to diaphragm level may have resulted from compression of small airways induced by both an increase of blood volume in the thorax and hydrostatic pressure against the abdomen. The changes induced by water immersion to neck level may have been exacerbated by the two mechanisms described above, in addition to hydrostatic pressure on the chest wall. The present results suggest that the significant reduction of pulmonary functional parameters caused by water immersion may be due to compression of small airways induced by an increase of blood volume in the thorax and hydrostatic pressure on the chest wall and abdomen.