The effects of moderate exercise training on natural killer cells and acute upper respiratory tract infections

A randomly controlled 15-wk exercise training (ET) study (five 45-min sessions/wk, brisk walking at 60% heart rate reserve) with a group of 36 mildly obese, sedentary women was conducted to investigate the relationship between improvement in cardiorespiratory fitness, changes in natural killer (NK) cell number and activity, and acute upper respiratory tract infection (URI) symptomatology. The study was conducted using a 2 (exercise and nonexercise groups) x 3 (baseline, 6-, and 15-wk testing sessions) factorial design, with data analyzed using repeated measures ANOVA. No significant change in NK cell number occurred as a result of ET as measured by the CD16 and Leu-19 monoclonal antibodies. ET did have a significant effect on NK cell activity (E:T 50:1) especially during the initial 6-wk period [F(2.68) = 12.34, p less than 0.001]. Using data from daily logs kept by each subject, the exercise group was found to have significantly fewer URI symptom days/incident than the nonexercise group (3.6 +/- 0.7 vs 7.0 +/- 1.4 days, respectively, p = 0.049). Improvement in cardiorespiratory fitness was correlated significantly with a reduction in URI symptom days/incident (r = 0.37, p = 0.025) and a change in NK cell activity from baseline to six but not 15 wks (r = 0.35, p = 0.036). In summary, moderate ET is associated with elevated NK cell activity after six but not 15 weeks, and reduced URI symptomatology in comparison to a randomized, sedentary control group.     

The effects of anabolic steroids and strength training on the human immune response

The immune response was assessed in 13 competitive bodybuilders self-administering anabolic-androgenic steroids and ten competitive bodybuilders not administering these drugs. Laboratory assessment included the number and relative distribution of T-cells, T-helper/inducer cells, T-cytotoxic/suppressor cells, activated T-cells, lymphocyte transformation to the mitogens, pokeweed mitogen (PWM), phytohemagglutinin (PHA), Concanavalin-A (CON-A), Staphylococcus aureus Cowan strain I (SAC), serum immunoglobulins, and natural killer (NK) activity. There were no significant differences in T-cell subsets among steroid users and non-users, but lymphocyte transformation studies revealed that the anabolic-androgenic steroid-using group had enhanced proliferative ability to the B-cell mitogen, SAC, in comparison to non-bodybuilding controls. NK activity was significantly (P less than 0.05) augmented in the anabolic-androgenic steroid users but not in the non-using bodybuilders. Serum immunoglobulin levels, in particular IgA, were significantly (P less than 0.017) lower in the steroid-using group. Four of 13 steroid users and three of eight non-steroid-using bodybuilders had detectable antinuclear antibodies. These studies indicate that 1) anabolic-androgenic steroid use as practiced by contemporary athletes is a potent modulator of immune responsiveness and 2) autoantibodies are prevalent in strength-trained men even in the absence of anabolic steroid use.     

The effects of acute moderate exercise on leukocyte and lymphocyte subpopulations

The extent and duration of changes in circulating leukocyte and lymphocyte subpopulations, cortisol, and catecholamines were examined in 12 women who walked 45 min at 60% VO2max in a laboratory setting. A two-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 points of measurement over a 24-h period), with treatment order counterbalanced. The 45-min walk, in comparison with rest in a seated position, was associated with a significant but moderate leukocytosis and lymphocytosis immediately following the walk. The leukocytosis was still evident after 3 h of recovery and was primarily due to a neutrophilia. The change in lymphocyte count, relative to baseline levels and the control condition, lasted less than 1.5 h, with an increase in the natural killer (CD16 and/or CD56) and cytotoxic T cell component (CD3 and CD16 and/or CD56) (NKCT) representing approximately two-thirds of the lymphocytosis and T cells (CD5) the other third. A significant decrease in the CD4:CD8 ratio was seen, with cytotoxic/suppressor (CD8) cells increasing and helper/inducer (CD4) cells demonstrating little change in comparison with baseline. This seems to have been due to a subpopulation of CD8 (low density antigen) cells, probably natural killer cells. The 45-min walk had no effect on plasma cortisol and epinephrine levels relative to the rest condition but was associated with a moderate increase in norepinephrine.(ABSTRACT TRUNCATED AT 250 WORDS)     

Anaerobic exercise induces moderate acute phase response

PURPOSE: It was intended to compare the immune reaction after single and repeated short bouts of anaerobic exercise. METHODS: Twelve unspecifically trained male subjects (27 +/- 2 yr, 75 +/- 2 kg, VO(2peak) 52 +/- 2 mL x min(-1) x kg(-1)) performed one 60-s all-out test (SMT) on a cycling ergometer and the same test followed by eight 10-s all-out tests every 5 min (AN-TS). These tests and one control day (Co-Day) were applied in randomized order. At rest and 15 min, 2 h, and 24 h after cessation of exercise the following venous blood parameters were determined: concentration of neutrophils and (CD16(+ -)) premacrophages (both flow-cytometrically), interleukin 6 and 8 (IL-6, IL-8), C-reactive protein (CRP) and cortisol. RESULTS: Two hours after cessation of exercise the neutrophils increased stronger after AN-TS than after SMT (P < 0.01). The peak in the number of premacrophages occurred earlier after SMT (15 min post; P < 0.01 to Co-Day) than after AN-TS (2 h post; P < 0.05 to Co-Day). IL-6 was elevated at 15 min and 2 h after AN-TS (P < 0.01 to SMT and Co-Day) but only slightly 2 h after SMT (P < 0.01 to Co-Day). There were no significant changes in IL-8. CRP was the only elevated parameter 24 h postexercise exclusively after AN-TS (P < 0.05 to Co-Day). CONCLUSIONS Repeated short anaerobic bouts of cycling lead to an acute phase response, which is more pronounced than after a single bout. Athletes should take care in performing such training sessions several times a week because signs of inflammation are detectable even 24 h after cessation of exercise.     

Acute effects of moderate exercise on plasma lipoprotein parameters

The acute, transient effects of moderate exercise on plasma lipoprotein parameters were assessed in 12 healthy, normolipidemic male volunteers subjected to a 5.5-km run at a comfortable pace. The course was completed in 31.5 min (range 23-43 min) and elicited a significant increase in pulse rate and plasma lactate levels and a fall in diastolic blood pressure. Of the plasma lipid parameters, total phospholipid, apo B-associated phospholipid, plasma triglyceride, and free fatty acid levels increased substantially immediately after the run and, except for triglyceride, were still raised 2 h later. Lesser but also significant increases were also noted in high-density lipoprotein-cholesterol (HDL-C), HDL3-C, and HDL-phospholipid concentrations after the run. The increase in HDL-phospholipid persisted for 2 h but the others returned to basal levels. Apolipoprotein Al, lecithin: cholesterol acyltransferase activity, total cholesterol, low-density lipoprotein-cholesterol, and the free cholesterol:cholesterol ester ratio remained essentially unaltered by exercise. The results were compatible with an increased secretion of triglyceride and phospholipid-rich VLDL, followed by the rapid clearance of the triglyceride moiety from the plasma and some redistribution of surface components to the HDL fraction.     

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)     

Plasma zinc and immune markers in runners in response to a moderate increase in training volume

Changes in plasma zinc concentration and markers of immune function were examined in a group of 10 male runners (n = 10) following a moderate increase in training over four weeks. Seven sedentary males acted as controls. Fasting blood samples were taken at rest, before (T0) and after (T4) four weeks of increased (+ 16 %) training and after two weeks of reduced (-31 %) training (T6). Blood was analysed for plasma zinc concentration, differential leucocyte counts, lymphocyte subpopulations and lymphocyte proliferation using incorporation of 3H-thymidine. The runners increased their training volume by 16 % over the four weeks. When compared with the nonathletes, the runners had lower concentrations of plasma zinc (p = 0.012), CD3 + (p = 0.042) and CD19 + lymphocytes (p = 0.010) over the four weeks. Lymphocyte proliferation in response to Concanavalin A stimulation was greater in the runners (p = 0.0090). Plasma zinc concentration and immune markers remained constant during the study. Plasma zinc concentration correlated with total leucocyte counts in the athletes at T6 (r = -0.72, p < 0.05) and with Pokeweed mitogen stimulation in the nonathletes at T6 (r = -0.92, p < 0.05). Therefore, athletes are unlikely to benefit from zinc supplementation during periods of moderately increased training volume.     

The immune response in hemodialysis patients following physical training

Abstract The effects of mild physical training on the cell-mediated and humoral immune responses were studied in 18 patients with end-stage renal disease (6.5±5.2 years on hemodialysis) participating in a six month exercise renal rehabilitation program. They were matched with 14 untrained patients for sex, age, years on hemodialysis and causes of renal disease. Serum immunoglobulins (IgA, IgM, IgG), IgG subclasses (IgG₁, IgG₂, IgG₃, IgG₄), complement components (C₃, C₄), interleukins IL-2, IL-4, IL-6, subpopulations of T lymphocytes and panel reactive lymphocytotoxic antibodies were determined on all patients. By the end of the study, peak aerobic capacity (VO₂ peak) was significantly improved by 42% in the trained group. This improvement was followed by a non-significant increase in IgE (by 13.8%) and in IgM (by 3%) and a decrease in IgA (by 17.5%, p<0.05), while the IgG levels remained constant. In the control group, there was no change in the levels of immunoglobulins. The values of interleukins, IgG subclasses, complement, lymphocytotoxic antibodies and T lymphocyte subsets remained almost unchanged in both groups. Finally, during the study, common upper respiratory infections were more often in the controls (58%), than in the trained patients (31%). The results suggest that physical training improves clinically the immune defense mechanisms in hemodialysis patients, although it does not significantly change cell-mediated and humoral immune responses.     

Acute effects of moderate intensity resistance exercise on bone cell activity

Resistance exercise has positive effects on bone mass, but little is known about the mechanisms by which this occurs. The purpose of this study was to determine if a single bout of moderate intensity resistance exercise alters biochemical markers of bone cell activity. Indices of bone turnover were measured in nine healthy, untrained men (21.9 +/- 1.2 yrs old), before and following a single 45 minute session of resistance exercise, and during a control trial. A cross-over design was used so that all participants performed both trials in random order. Blood samples were collected immediately before, immediately after, and at 1, 8, 24, and 48 hours post exercise and analyzed for bone-specific alkaline phosphatase (BAP), type I collagen propeptide (PICP), and type I collagen N-telopeptide (sNTX). Urine from the second morning void was collected over four days (day before, day of, and two days following exercise) and analyzed for type I collagen N-telopeptide (uNTX). Exercise resulted in a significant increase (p < 0.05) in the ratio of biochemical markers of bone formation to bone resorption eight hours post exercise, largely due to a decrease in sNTX. Markers return to baseline within 24 hrs. These data suggest that moderate intensity resistance training acutely reduces bone resorption, leading to a favorable change in overall bone turnover, for at least 8 hours post exercise in untrained young men. Further work is needed to determine if long-term benefits to bone strength follow with persistent training.     

The effects of exercise training intensification on glucose disposal in elite cyclists

To assess the effect of training on glucose disposal, we performed a longitudinal study of 11 elite cyclists before and after 4 months of intensive training compared to 11 sedentary subjects. Insulin sensitivity (SI) and glucose effectiveness (Sg) were measured using Bergman's minimal model. Sg includes basal insulin effectiveness (BIE) and a parameter termed glucose effectiveness at zero insulin (GEZI). After overnight fasting glucose was administered intravenously (0.5 g x kg(-1), 30% solution given over 3 min), and insulin (0.02 U x kg(-1), 1 -2U) was injected immediately after 19 min. Sg, SI and BIE, were significantly higher in elite cyclists both before and after training than in sedentary subjects (P < 0.01). However, the non-insulin-dependent component of Sg (GEZI) was higher only after the intensive training in the cyclists (3.31 +/- 0.67% x min(-1)) than in sedentary subjects (1.7 +/- 0.2% x min(-1), P < 0.02). We conclude that insulin sensitivity (SI) and glucose effectiveness (Sg) are higher in elite cyclists than in sedentary subjects and that these high and almost optimal values are not further improved by additional training. However, the improvement in GEZI, as reflected by the difference between post-training GEZI and sedentary control values, raises the possibility of an increase of the non-insulin-mediated mobilization of glucose transporters.     

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 effects of a nucleotide supplement on salivary IgA and cortisol after moderate endurance exercise

AIM: The aim of this work was to determine the ergogenic effects of a nucleotide supplement on salivary immunoglobulin A (SIgA) and cortisol (C) responses after prolonged endurance cycle exercise. METHODS: Fourteen moderately trained male subjects (mean body mass and VO2max) completed 2 90-min cycle ergometer trials (60% VO2max) prior to and after 60 days of either a nucleotide (E group, n=7) or placebo (P group, n=7) supplement. Each of the subjects provided an unstimulated saliva sample prior to and following the exercise for determination of SIgA and C. RESULTS: SIgA was significantly lower after exercise trials in both E and P groups (P<0.0001) prior to as well as after the supplementation period. However, SIgA was significantly higher (P<0.01) in the E group than the P group after supplementation. There were no significant (P>0.11) differences in pre-exercise C level. Postexercise C concentrations were significantly (P<0.001) higher than pre-exercise levels in both groups of subjects. However, after the supplementation period, C concentration was significantly (P<0.0001) lower after exercise in E compared to P. CONCLUSIONS: This work suggests that a nucleotide supplement, given chronically may offset the hormonal response associated with demanding endurance exercise.     

Effects of chronic intense exercise training on the leukocyte response to acute exercise.

Circulatory leukocytes vary significantly in response to acute bouts of exercise. However, little is known concerning the adaptability of this response to chronic intense exercise training. We investigated the circulating leukocytic response to acute exercise in trained athletes during a 28-day intense exercise training program. On day 0, 14, 28 and two days after cessation of the increased training, eight trained male athletes (VO2max greater than 60 ml.kg-1.min-1) were subjected to a 20-km bicycle ergometer time trial. Blood samples were drawn before (PRE, for resting baseline values) and five minutes after (POST, response to acute exercise) the time trial. Beginning on day 0, athletes were instructed to increase the duration of their training 50%. The intense exercise training, which lasted 28 days, was verified weekly. Acute bouts of exercise caused a significant increase (p less than 0.05) in circulating white blood cells, lymphocytes, polymorphonuclear neutrophils and monocytes. The baseline resting values and the magnitude of the response to the acute bouts of exercise in the above parameters were not different during the 28 days of chronic intense exercise training or 2 days after cessation of training as compared to the values observed on day 0. Similarly there was a significant increase (p less than 0.05) in cortisol levels in response to the acute bouts of exercise during the chronic intense exercise training, but the increases were not different from that observed under baseline conditions. These results lead to the conclusion that chronic intense exercise training does not alter the circulating leukocytic response to acute exercise.     

The effects of acute moderate exercise on serum lipids and lipoproteins in mildly obese women.

The extent and duration of serum lipid and lipoprotein changes were examined in 12 mildly obese women who walked 45 minutes at 60% VO2max in a laboratory setting. A two-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-hour period) with treatment counterbalanced. The patterns of change in total high-density lipoprotein-cholesterol (HDL-C) [F(5,55) = 5.75, p less than 0.001] and HDL3-C [F(5,55) = 2.62, p = 0.034], but not HDL2-C [F(5,55) = 1.15, p = 0.346], were significantly different between conditions. Relative to baseline and the rest condition, total HDL-C tended to rise due to a significant 11.6% increase in HDL3-C immediately post-exercise, with values returning to baseline 1.5 hours post-exercise. The interaction statistic for triglycerides was significant with trends for a decrease in triglycerides at 1.5 and 23 hours post-exercise relative to baseline and the rest condition. No significant differences were seen between the exercise and rest conditions for total cholesterol, low-density lipoprotein cholesterol, glucose, or plasma volume. These data indicate that an exercise intensity achievable by brisk walking (7.4 kph) is sufficient to evoke significant but short-term changes in serum HDL3-C concentrations in women.     

Effects of hyperoxic training on performance and cardiorespiratory response to exercise

PURPOSE: To determine whether training in a hyperoxic environment would result in greater increases in VO2max and performance at 90% VO2max as compared with training in normoxia. METHODS: In a single blind design nine athletes trained for 6 wk on a cycle ergometer 3 d.wk(-1), 1 h.d(-1) (10 x 4-min intervals, with 2 min of rest between intervals) at 90% HR(max). Training HR range was maintained by adjusting the power output. Subjects were randomly assigned to H (60% O2) or N (21% O2) breathing conditions for training. After 12 wk of detraining, a second 6-wk training protocol was completed with the breathing conditions reversed. VO2max, performance time at 90% VO2max and cardiorespiratory response to a steady-state exercise at 80% VO2max were measured pre- and posttraining. All pre- and posttraining tests were conducted under normoxic conditions. RESULTS: There were no significant differences between pretraining results for any of the parameters. Power output was 8.1% higher while training in H compared with N, to maintain training HR. Both H and N training resulted in increased performance time, with H being greater than N. Although there was a trend for a greater increase in VO2max after H versus N training, this difference was not significant. HR(max) did not change for H or N. HR VE at 80% VO2max decreased posttraining with no differences between H and N. CONCLUSION: The data showed that a higher power output was required to maintain HR during H training. This increased training intensity during H resulted in improved exercise performance whereas cycling at 90% VO2max in room air and may be due to peripheral factors because cardiorespiratory responses were similar.