The effect of exhaustive exercise on salivary immunoglobulin A.

The purpose of this study was to examine salivary immunoglobulin A (s-IgA) responses to exhaustive exercise. Twenty-nine, college age (means +/- SD = 21.45 +/- 3.1 yrs; range 18-29 yrs) moderately active males (running < 10 miles per week) performed an incremental treadmill test to exhaustion. Unstimulated salivary samples, collected before as well as immediately and one hour following the test, were analyzed for s-IgA using an enzyme-linked immunosorbent assay (ELISA). Mean s-IgA levels decreased significantly (24.4%, p < 0.05) immediately following the maximal test, and remained depressed (16.9%) one hour after the test. Of the 29 subjects, five exhibited an increase (range = 1.3 to 53.3%) in s-IgA following the exercise bout. The results of this study suggest that exhaustive exercise may temporarily reduce salivary IgA levels.     

The effects of acute moderate exercise on lymphocyte function and serum immunoglobulin levels

The extent and duration of changes on lymphocyte function and serum immunoglobulin (Ig) levels were examined in 12 women who walked 45 min at 60% VO2 max in a laboratory setting. A 2-factor, 2 x 6 design with repeated measures on both factors was utilized. The first factor was condition (exercise and rest), and the second factor was time (six times of measurement over a 24-h period), with treatment order counterbalanced. The 45-min walk, in comparison to rest in a seated position, was not associated with significant changes in circulating numbers of interleukin-2-activated T cells (CD5 and CD25) or on spontaneous or concanavalin-A-stimulated lymphocyte proliferation. A trend for decreased phytohemagglutinin-stimulated lymphocyte proliferation in comparison to the rest condition, however, was seen 1.5 h following the exercise bout (p = 0.047). The patterns of change for serum IgG, IgA, and IgM were significantly different (p = 0.001, p less than 0.001, p = 0.010, respectively) between conditions. IgG rose 7.2% immediately following exercise, and then returned to baseline 1.5 h later, which contrasted significantly with changes in the rest condition. These same patterns of change occurred also with IgA and IgM, but increases immediately following exercise were not significant, although a trend was seen for IgA (p = 0.03). The 45-min walk had no effect on plasma cortisol and epinephrine levels relative to the rest condition, but was associated with a significant 89% increase in norepinephrine.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of exercise training on salivary immunoglobulin A and cortisol responses to maximal exercise.

The salivary immunoglobulin A (s-IgA) and cortisol responses to maximal exercise were examined in 24 adult males (X +/- SD; 22.1 +/- 3.0 yrs) before and after 10 weeks of run training. The subjects performed an incremental treadmill test to exhaustion and were randomly assigned to one of three groups: control (CON; n = 5), low intensity training (LO; n = 8), or high intensity training (HI; n = 11). Following the ten weeks of training, the subjects performed a second maximal treadmill test. Saliva samples were collected before, as well as immediately and 1 hr following each of the maximal treadmill tests and were analyzed for s-IgA and salivary cortisol. Maximal oxygen consumption (VO2max) increased significantly (p < 0.05) in the LO and HI groups but remained unchanged in the CON group. The s-IgA levels decreased significantly (p < 0.05) immediately post-exercise but returned to pre-exercise levels by one hour recovery. In addition, s-IgA and cortisol levels were not significantly (p > 0.05) correlated at any of the sampling times. These findings indicated that the s-IgA response to maximal exercise was unaffected by moderate (70% of VO2 max) to heavy (86% of VO2max) training (designed to develop cardiorespiratory fitness in healthy non-athletic adults) and independent of salivary cortisol.     

Effect of moderate intensity aerobic exercise training on electrophysiological and biochemical correlates of sleep

Background

Sleep disturbance (SD) is quite prevalent among collegiate students and is reflected upon various scales of measurements such as electrophysiological and biochemical. Despite its high prevalence and negative consequences, very few studies have focussed on the management of SD in collegiates. Aerobic exercise (AE) is associated with improvement in sleep and due to its extensive benefits, it has been now considered as an alternative management strategy for SD.

Aim

To investigate the effect of 12-week AE training on electrophysiological and biochemical correlates of sleep in collegiate students.

Methods

Twenty-eight collegiate students with Pittsburgh sleep quality index score?>?5 were randomly assigned into two groups: AE and control. Both the groups were taught basic sleep hygiene (SH) at the beginning of study. AE group, in addition to SH, received 12 weeks of moderate intensity AE training on treadmill. Pre- and post-intervention measures were performed at baseline and after 12 weeks. Sleep latency (SL), total sleep time, percentage of N1, N2, N3, NREM, REM and sleep efficiency (SE%) were calculated from over-night polysomnography (PSG). Concentration of serum melatonin and cortisol were also measured pre and post intervention.

Results

2?×?2 mixed ANOVA resulted in significant decrease and increase in N1% and N3%, respectively, after 12 weeks of AE. Serum cortisol also showed a significant decrease in its concentration post-intervention. Serum melatonin and other PSG variables did not show any difference with AE training.

Conclusion

AE training for 12 weeks improved sleep on electrophysiological and biochemical scales in SD collegiates.

Trial registration number and date

CTRI/2019/05/019154.

     

The effect of exercise at various temperatures on salivary levels of immunoglobulin A.

The purpose of this investigation was to determine the effect of ambient temperature on the salivary immunoglobulin A (s-IgA) response to submaximal exercise. Nine adult males (x age +/- SD = 22 +/- 2 yrs) volunteered to perform an incremental treadmill test to exhaustion for the determination of VO2max and three 30-minute treadmill runs at 80% VO2max in an environmental chamber at temperatures of approximately 6, 19 and 34 degrees C. Saliva samples were collected prior to each submaximal workbout as well as immediately and 1 hr post-exercise. A 2 within subjects factors (temperature, sample time) repeated measures ANOVA indicated no significant interaction or main effects for sampling time or temperature. The results of this study indicated that 30 minutes of non-competitive exercise at temperatures ranging from 6 to 34 degrees C had no effect on s-IgA. These findings suggest that moderate intensity exercises at a wide range of ambient temperatures does not increase the susceptibility to upper respiratory infection by decreasing s-IgA.     

A rat model of saliva secretory immunoglobulin: a suppression caused by intense exercise

We aimed to develop a valid model of immunosuppression induced by intense exercise in rats. Rats were divided into three groups. In the rest (Rest) group, saliva was collected from resting rats on 4 consecutive days. In the exercise (Ex) group, rats ran on a treadmill until exhaustion (exercise time: 60.0 +/- 3.7 min), and their saliva was collected before and after exercise; the salivary glands were removed after exercise. In the control (Con) group, saliva collection and gland removal were also performed, but the rats did not exercise. Secretory immunoglobulin A (SIgA) concentrations in saliva and polymeric immunoglobulin receptor (pIgR) mRNA expression in the glands were measured. There was no significant change in SIgA concentration in the Rest group over 4 days. In the Ex group, SIgA concentration decreased significantly after exercise compared with before, whereas there was no significant change in the Con group. The expression of pIgR mRNA was significantly lower in the Ex group post-exercise than in the Con group. Our procedure for saliva collection appeared suitable, and the exercise-induced SIgA suppression was probably caused by a decline in pIgR mRNA expression. We propose to use this reproducible and reliable rat model of exercise-induced SIgA suppression in future studies.     

The effect of food matrix on carbohydrate utilization during moderate exercise.

The effect of food matrix on carbohydrate utilization during moderate exercise. Med. Sci. Sports Exerc., Vol. 24, No. 3, pp. 320-326, 1992. To determine the effect of food type and form on the rate of assimilation and utilization of a meal given before exercise, five physically active adult males walked for 4 h on a 10% uphill graded treadmill at 40% VO2max. After a 12-h fast, and 30 min before exercise, subjects ingested 70 g of liquid glucose (G), a refined "hot cereal" (R), a refined "hot cereal" with water-soluble fiber (R/F), an oat bar (O), or placebo (P). Meals R/F, R, and O had significantly lower (P less than 0.05) peak plasma glucose responses than meal G (0.8, 0.9, 1.0, and 2.4 mmol.l-1, respectively). Meals R, O, and R/F had significantly lower (P less than 0.01) peak insulin responses than meal G (135, 150, 190, and 340 pmol.l-1, respectively). All meals except P contained an extrinsic tracer of 200 mg UL-13C-glucose. Mean (+/- SD) total recovery of the administered dose of 13C for all meals was 81 +/- 2%. Both O (34 +/- 4% dose.h-1) and R/F (30 +/- 3% dose.h-1) had significantly lower peak recoveries than did meal G (41 +/- 5% dose.h-1). Meal R/F had a significantly lower (P less than 0.05) rate of exogenous glucose oxidation than meal G during the first hour of exercise. These data suggest that meal R/F slows the rate of assimilation and utilization of exogenous glucose, but does not alter the cumulative 4-h utilization.     

The effect of aerobic exercise training on the lipid-lipoprotein profile of children and adolescents

Longitudinal paediatric population studies have provided evidence that the risk factor theory may be extended to children and adolescents. These studies could assist in identifying individuals at increased coronary risk. Numerous studies have focused on the effects of regular exercise on the paediatric lipoprotein profile, a recognised primary risk factor, with equivocal results. Cross-sectional comparisons of dichotomised groups provide the strongest evidence of an exercise effect. 'Trained' or 'active' children and adolescents demonstrate 'favourable' levels of high density lipoprotein-cholesterol (HDL-C), triacylglycerol, total cholesterol (TC)/HDL-C and low density lipoprotein-cholesterol (LDL-C)/HDL-C, whilst TC is generally unaffected. The evidence regarding LDL-C in these studies is equivocal. A possible self-selection bias means that a cause-effect relationship between exercise and the lipoprotein profile cannot be readily established from this design. Correlational studies are difficult to interpret because of differences in participant characteristics, methods employed to assess peak oxygen uptake and habitual physical activity (HPA), and the statistical techniques used to analyse multivariate data. Directly measured cardiorespiratory fitness does not appear to be related to lipoprotein profiles in the children and adolescents studied to date, although there are data to the contrary. The relationship with HPA is more difficult to decipher. The evidence suggests that a 'favourable' lipoprotein profile may be related to higher levels of HPA, although differences in assessment methods preclude a definitive answer. While few prospective studies exist, the majority of these longitudinal investigations suggest that imposed regular exercise has little, if any, influence on the lipoprotein levels of children and adolescents. However, most prospective studies have several serious methodological design weaknesses, including low sample size, inadequate exercise training volume and a lack of control individuals. Recent studies have suggested that increases in HDL-C and reductions in LDL-C may be possible with regular exercise. The identification of a dose-response relationship between exercise training and the lipoprotein profile during the paediatric years remains elusive.     

The effect of exhausting aerobic exercise on the timing of anticipatory postural adjustments

AIM: The aim of the study was to investigate the influence of exhausting aerobic exercise on the timing of anticipatory postural adjustments (APAs). METHODS: The APAs of 12 participants were recorded at baseline, after a .VO2max running test, and again following a 45-min rest period. APAs were induced using a rapid bilateral arm-raising maneuver, and were analyzed in the rectus abdominis, hamstring group, gluteal group, and lumbar and thoracic paraspinal muscles using electromyography. Postural stability was assessed by monitoring anterior/posterior displacement of the center of pressure using a force plate. We hypothesized that APA onset would be ear lier following exhausting aerobic exercise as compared to the baseline measures, but that this effect would be transient (i.e., APA onset following the rest period would not differ from that at baseline). RESULTS: Exhausting aerobic exercise resulted in a significantly earlier APA in one of the 5 muscles evaluated, the thoracic paraspinal group, and this effect persisted 45-min postexercise. Exhausting aerobic exercise did not affect postural stability during the rapid arm-raising maneuver. CONCLUSION: The findings lend tentative support for the notion that earlier APAs constitute a functional adaptation by the motor system to maintain postural stability in the presence of fatigue.     

Maternal respiration and blood gases during aerobic exercise performed at moderate altitude.

We studied whether maternal acid-base status during aerobic exercise performed at moderate altitude is affected by pregnancy. Seven primiparus women were tested at 37 wk gestation and 12 wk postpartum. Subjects were studied at rest, and during two cycle (50 W, 75 W) and two treadmill (67 m.min-1; 2.5% grade, 67 m.min-1; 12% grade) protocols. Exercise bouts lasted 6 min with a 10-min rest between sessions. Minute (VE) and alveolar (VA) ventilation, tidal volume (VT), and ventilatory equivalent for carbon dioxide (VE/VCO2) were significantly (P less than 0.01) greater when exercise was performed during pregnancy. Physiological dead space (VD) was not affected by pregnancy status and did not differ between rest and exercise. Decreases (P less than 0.01) in arterial pH during exercise averaged 0.04 units in both pregnancy and postpartum. Despite similar change in maternal pH, carbon dioxide tension (PaCO2) remained unchanged during exercise at 37 wk gestation but decreased at 12 wk postpartum. Decreases in arterial bicarbonate [HCO3-] associated with exercise were smaller during pregnancy. Our findings indicate that pregnancy did not compromise maternal acid-base status during aerobic exercise.     

The effect of strenuous aerobic exercise on skeletal muscle myofibrillar proteolysis in humans

Relatively little is known about the dynamics of the skeletal muscle protein pool following aerobic exercise. Myofibrillar protein synthesis has recently been shown to be substantially elevated for 3 days after a strenuous 60 min bout of one-legged aerobic exercise, and this increase was surprisingly equal to or greater than what has been shown numerous times following resistance exercise over the same time course. Because net protein accretion is the sum of protein synthesis and degradation, we sought to directly measure skeletal muscle myofibrillar proteolysis in five healthy young males in response to an identical strenuous 60 min aerobic exercise bout and at the same time points (rest, 6, and 24 h post-exercise and 48 and 72 h post-exercise in a subset of subjects). We measured skeletal muscle myofibrillar proteolysis by monitoring the release of the natural tracer 3-methylhistidine (3MH) from the vastus lateralis muscle into the interstitial space via microdialysis. Skeletal muscle interstitial 3MH concentration was no different (P>0.05) from rest (5.16+/-0.38 nmol/mL) after 6 (5.37+/-0.55 nmol/mL), 24 (5.40+/-0.26 nmol/mL), 48 (5.50+/-0.74 nmol/mL), or 72 h (4.73+/-0.28 nmol/mL). These results suggest that proteolysis of the myofibrillar fraction of skeletal muscle is relatively refractory to an intense aerobic exercise stimulus for up to 3 days, despite the large increase in synthesis of this muscle fraction following the same exercise stimulus. The apparent net myofibrillar protein accretion in the hours and days after exercise may occur in order to offset the large elevation in mixed muscle proteolysis that has been shown during similar bouts of intense one-legged aerobic exercise.     

The effect of interval sprinting exercise on vascular function and aerobic fitness of post-menopausal women

Menopausal transition accelerates an age-associated decrease in vascular function and a decline in aerobic fitness. The purpose of this study was to examine the effect of 8 weeks of interval sprinting cycle ergometer exercise on arterial stiffness, basal forearm blood flow, and aerobic fitness of post-menopausal women. Sixty overweight post-menopausal women were randomized into either exercise (Ex, n = 30) or control (C, n = 30) groups. Ex participants completed 24 interval sprinting exercise (ISE) sessions over 8 weeks. Each 20-minute ISE session comprised of alternating 8 seconds sprints and 12 seconds of light pedaling. Arterial stiffness assessed through ankle-brachial pulse wave velocity (baPWV) and augmentation index (AIx), basal forearm blood flow (FBF) assessed using venous occlusion, and aerobic fitness were assessed before and after the intervention. baPWV was significantly decreased in the Ex group by 7.2%, P = .03, whereas AIx demonstrated a 10% decrease, P = .002. No changes were found in basal FBF. Aerobic fitness was significantly increased, P = .002, in the Ex group (14%) with no change occurring in the control group.ISE training, despite minimal exercise commitment time (8 hours over 8 weeks), significantly lowered the arterial stiffness and increased the aerobic fitness of post-menopausal women. These results suggest that ISE positively influences the negative change in arterial stiffness and aerobic fitness that typically accompanies menopause.     

The effect of detraining and reduced training on the physiological adaptations to aerobic exercise training

In previously sedentary individuals, regularly performed aerobic exercise results in significant improvements in exercise capacity. The development of peak exercise performance, as typified by competitive endurance athletes, is dependent upon several months to years of aerobic training. The physiological adaptations associated with these improvements in both maximal exercise performance, as reflected by increases in maximal oxygen uptake (VO2max), and submaximal exercise endurance include increases in both cardiovascular function and skeletal muscle oxidative capacity. Despite prolonged periods of aerobic training, reductions in maximal and submaximal exercise performance occur within weeks after the cessation of training. These losses in exercise performance coincide with declines in cardiovascular function and muscle metabolic potential. Significant reductions in VO2max have been reported to occur within 2 to 4 weeks of detraining. This initial rapid decline in VO2max is likely related to a corresponding fall in maximal cardiac output which, in turn, appears to be mediated by a reduced stroke volume with little or no change in maximal heart rate. A loss in blood volume appears to, at least partially, account for the decline in stroke volume and VO2max during the initial weeks of detraining, although changes in cardiac hypertrophy, total haemoglobin content, skeletal muscle capillarisation and temperature regulation have been suggested as possible mediating factors. When detraining continues beyond 2 to 4 weeks, further declines in VO2max appear to be a function of corresponding reductions in maximal arterial-venous (mixed) oxygen difference. Whether reductions in oxygen delivery to and/or extraction by working muscle regulates this progressive decline is not readily apparent. Changes in maximal oxygen delivery may result from decreases in total haemoglobin content and/or maximal muscle blood flow and vascular conductance. The declines in skeletal muscle oxidative enzyme activity observed with detraining are not causally linked to changes in VO2max but appear to be functionally related to the accelerated carbohydrate oxidation and lactate production observed during exercise at a given intensity. Alternatively, reductions in submaximal exercise performance may be related to changes in the mean transit time of blood flow through the active muscle and/or the thermoregulatory response (i.e. degree of thermal strain) to exercise. In contrast to the responses observed with detraining, currently available research indicates that the adaptations to aerobic training may be retained for at least several months when training is maintained at a reduced level. Reductions of one- to two-thirds in training frequency and/or duration do not significantly alter VO2max or submaximal endurance time provided the intensity of each exercise session is maintained.(ABSTRACT TRUNCATED AT 400 WORDS)     

Reducing induced state anxiety: effects of acute aerobic exercise and autogenic relaxation.

The purpose of this study was to investigate the effects of acute aerobic activity an an autogenic relaxation session on reducing induced state anxiety. Eighty-five university students were randomly assigned to one of three groups (a) aerobic, (b) relaxation, (c) control. Each group was tested separately. The general procedure consisted of anxiety induction, assessment, intervention, and assessment. The induced affect procedure involved having subjects visualize distressing images and generating high arousal states for ten minutes (Smith and Ascough, 1985). State anxiety was assessed by State-Trait Anxiety Inventory (form Y-1). The aerobic intervention lasted 40 minutes, including warm-up and cool-down. The relaxation intervention consisted of listening and following instructions on a tape for approximately 30 minutes (Budzyski T, 1974, "Limb Heaviness-Exercise MU3-3"). The control group was excused after anxiety induction and told to report back in 30 minutes. The data was analyzed by a 3 x 2 (groups by time) ANOVA with repeated measures on the last factor. The groups by times interaction was significant, F(2,82) = 13.07, p less than 0.01. Post-hoc analysis using Tukey with a normalized n indicated that both the aerobic and relaxation groups significantly reduce anxiety scores from pretreatment to post-treatment but were not different from each other. Both groups were significantly different from the control. The findings support the argument that an acute aerobic activity and relaxation session can reduce induced anxiety. These results have implications for motivating individuals to engage in exercise and activity to relieve anxiety generated by an acute stressor.     

No effect of moderate hypohydration or hyperthermia on anaerobic exercise performance

PURPOSE: This study examined the effects of hypohydration and moderate hyperthermia (core temperature elevation) on anaerobic exercise performance in a temperate environment. METHODS: Eight active males completed two passive heat exposure trials (180 min, 45 degrees C, 50% rh) with (EUH) and without (HYP) fluid replacement. A single 15-s Wingate anaerobic test (WAnT) was used to assess anaerobic performance (peak power, mean power, and fatigue index) before (-180 min) and again at three time points after passive heat exposure to include immediately (0 min), 30 min, and 60 min after in a temperate environment (22 degrees C). Rectal temperature (Tc) was measured throughout the experiment. RESULTS: HYP reduced body mass (2.7+/-0.7%) (P<0.05) but had no effect on any WAnT performance measure. Passive heat exposure elicited moderate hyperthermia in both trials (EUH: 0.6 degrees C; HYP: 1.0 degrees C) and returned to baseline within 30-60 min following similar decay curves. HYP Tc remained higher (0.4 degrees C) than EUH throughout testing (P<0.05), but moderate hyperthermia itself produced no independent effect on anaerobic exercise performance in either trial. CONCLUSIONS: This study demonstrates that neither moderate HYP nor the moderate hyperthermia accompanying HYP by passive heat exposure affect anaerobic exercise performance in a temperate environment.     

The impacts of an eight-week moderate aerobic exercise training on some gene expression involved in cholesterol metabolism in ovariectomized rats

Sport Sciences for Health - Estrogen depletion in postmenopausal women and animal models of ovariectomy is associated with some undesirable alternations in lipid metabolism, the adverse impacts of...