Effects of Unaccustomed and Accustomed Exercise on the Immune Response in Runners

Acute supplementation with a curcuminoid-based formulation fails to enhance resting or exercise-induced NRF2 activity in males and females

Purpose: Exercise and (poly)phenols may activate nuclear factor erythroid 2-related factor 2 (NRF2), a transcription factor that coordinates antioxidant synthesis. The purpose of this study was to determine whether curcuminoid supplementation augments resting and exercise-induced NRF2 activity. Methods: In a double-blinded, randomised, between-subjects design, 14 males and 12 females performed plyometric exercise (100 drop jumps, 50 squat jumps) following 4 d supplementation with a curcuminoid-based formulation (CUR + EX; n = 13; ∼200 mg d-1 curcuminoids) or a placebo (PLA + EX; n = 13). NRF2/DNA binding in peripheral blood mononuclear cells, plasma glutathione peroxidase (GPX), and plasma cytokines (interleukin-6 [IL-6], tumour necrosis factor-alpha [TNF-α]) were measured pre-, post-, 1, 2 h post-exercise. Curcuminoid metabolites were measured 0, 1, 2 h post-administration of a single bolus. Results: Total area under the curve for total curcuminoid metabolites was greater in CUR + EX (p < 0.01), with bioavailability peaking at 2 h post administration (CUR + EX: [0 h] 80.9 ± 117 nM [1 h] 76.6 ± 178.5 nM [2 h] 301.1 ± 584.7 nM; PLA + EX: [0 h] 10.4 ± 1.6 [1 h] 8.5 ± 2.6 [2 h] 10.6 ± 2.1). NRF2 activity did not increase in PLA + EX (p = 0.78) or CUR + EX (p = 0.76); however, curcuminoid metabolite concentrations did positively predict NRF2/DNA binding (R2 = 0.39; p = 0.02). Exercise increased IL-6 (p = 0.03) but TNF-α was unresponsive (p = 0.97) and lower across PLA + EX (p = 0.03). GPX activity was higher in CUR + EX (p < 0.01) but not in PLA + EX (p = 0.94). Conclusion: Supplementation with a curcuminoid-based formulation failed to augment resting or exercise-induced NRF2/DNA binding; however, higher concentrations of curcuminoid metabolites predicted NRF2/DNA binding response, suggesting effects may be dependent on bioavailability.

Supply of Antioxidants vs. Recruit Firefighters' Cellular Immune Status: A Randomized Double-Blinded Placebo-Controlled Parallel-Group Trial

Background: Physical exercise can affect the immune system. We studied the effect of antioxidants on hematological and immune biomarkers after heavy training. Methods: 24 well-trained and well-fed male firefighters were randomly divided into supplemented and placebo groups, and tested for immunology-related variables using venous blood samples in the fasting state, pre- (M1) and post- (M2) five weeks of daily micronutrient supplementation (15 mg of beta-carotene, 200 mg of vitamin C, 136 mg of vitamin E, 200 μg of selenium, 15 mg of zinc, 100 mg of magnesium). Total leukocytes and a differential count for five populations were determined using standard procedures (MAXM—Beckman Coulter Diagnostics; Brea, CA, USA). Lymphocyte subsets were determined through immunophenotyping. Results: Although all values were within the normal range for healthy adults and athletes in the supplemented group (SG), mean CD3+CD8+, CD8+ and CD16+CD56+ decreased (p < 0.05; small to moderate effects), while mean CD4+, CD19+ and CD4+/CD8+ increased (p < 0.05; small effects) after five-weeks. Regarding the placebo group (PG), higher total leukocyte count (p < 0.05; trivial effect) and natural killer cells percentage (CD16+CD56+; p < 0.05; moderate effect) were observed when comparing M1 and M2. Conclusions: Antioxidants supplementation did not alter well-fed male firefighters recruit firefighters’ immune cell response during the five-week physical training program.

Effects of Traditional Chinese Acupuncture Compared with Sham Acupuncture on the Explosive Force Production by the Forearm Muscles in Female: A Randomized Controlled Trial

Background

Acupuncture can effectively enhance musculoskeletal rehabilitation, with effects such as reduced pain intensity and muscle tension and decreased disability.

Objective

The purpose of this study was to determine the efficacy of traditional Chinese acupuncture (TCA) compared with sham acupuncture (SA) in explosive force production by the forearm muscles in females.

Methods

A total of 32 subjects were included and randomly assigned to two groups: TCA group (n = 16): stimulated specific acupoints including Quchi (LI11), Shousanli (LI10), Hegu (LI4), Xiaohai (SI8), Tianjing (SJ10), and Waiguan (SJ5) for 15 minutes; SA group (n = 16): using superficial needle insertion at nonacupoints without stimulation. The subjects warmed up for the 3-time isokinetic test with an angular velocity of 30°/s and then performed a set of 15 full flexion (Flex) and extension (Ext) with an angular velocity of 180°/s using the CON-TREX isokinetic test training system recorded as the pretest. After acupuncture for 15 min, perform a set of the same isokinetic movement isokinetic records as the posttest. The average max torque, average work, average power, average peak power, average max speed, and total work were collected to evaluate the forearm explosive force changes. Use two-way repeated measures ANOVA to compare the difference before and after acupuncture between two groups.

Results

The results showed that acupuncture conditions (sham acupuncture as well as true acupuncture) and the intervention times (not acupuncture or acupuncture for 15 min) have a significant interaction effect on forearm explosive force and joint stiffness (P < 0.05). The simple main effect showed that the selected parameters of the TCA group increased significantly after acupuncture (P < 0.05), while the SA group did not (P > 0.05). We speculate that the activation of muscle may be related to the selected acupuncture points.

Conclusion

Acupuncture can produce excitation in motor nerves and muscles, and nerve stimulation increases the recruitment of motor units, thus improving the muscle explosive force.

Continuous Protein Supplementation Reduces Acute Exercise-Induced Stress Markers in Athletes Performing Marathon

The aim of this study was to determine the changes in endurance performance and metabolic, hormonal, and inflammatory markers induced by endurance stress (marathon race) in a combined strategy of training and dietary protein supplementation. The study was designed as a randomised controlled trial consisting of regular endurance training without and with a daily intake of a soy protein-based supplement over a three-month period in 2 × 15 (10 males and 5 females per group) endurance-trained adults. Body composition (body mass, BMI, and fat mass) was determined, and physical fitness was measured by treadmill ergometry at baseline and after 3 months of intervention; changes in exercise-induced stress and inflammatory markers (CK, myoglobin, interleukin-6, cortisol, and leukocytes) were also determined before and after a marathon competition; eating behaviour was documented before and after intervention by a three-day diet diary. Although no significant influence on endurance performance was observed, the protein supplementation regime reduced the exercise-induced muscle stress response. Furthermore, a protein intake of ≥20% of total energy intake led to a lower-level stress reaction after the marathon race. In conclusion, supplementary protein intake may influence exercise-induced muscle stress reactions by changing cellular metabolism and inflammatory pathways.

Effects of Exercise on Stress-induced Attenuation of Vaccination Responses in Mice

Studies suggest that exercise can improve vaccination responses in humans. Chronic stress can lead to immunosuppression, and there may be a role for exercise in augmenting immune responses.

PURPOSE

To investigate the effects of acute eccentric exercise (ECC) and voluntary wheel exercise training (VWR) on antibody and cell-mediated immune responses to vaccination in chronically stressed mice. We hypothesized that both ECC and VWR would attenuate chronic stress-induced reductions in vaccination responses.

METHODS

Mice were randomized into four groups: control (CON), stress (S)-ECC, S-VWR, and S-sedentary (SED). Stressed groups received chronic restraint stress for 6 h·d, 5 d·wk for 3 wk. After the first week of stress, S-ECC were exercised at 17 m·min speed at -20% grade for 45 min on a treadmill and then intramuscularly injected with 100 μg of ovalbumin (OVA) and 200 μg of alum adjuvant. All other groups were also vaccinated at this time. Stress-VWR mice voluntarily ran on a wheel for the entire experiment. Plasma was collected before, and at 1, 2, and 4 wk postvaccination. Enzyme-linked immunosorbent assay was performed to analyze anti-OVA IgG and IgM antibodies. After 3 wk of chronic stress, all mice were injected with OVA into the ear to determine the delayed-type hypersensitivity.

RESULTS

We found that chronic restraint stress significantly reduced body weight and caused adrenal hypertrophy. We also found both S-ECC and S-VWR groups had significantly elevated anti-OVA IgG (P < 0.05), whereas no significant differences between the two exercise groups. Neither S-ECC nor S-VWR altered anti-OVA IgM or delayed-type hypersensitivity responses compared with S-SED group.

CONCLUSIONS

Acute eccentric exercise and voluntary exercise training alleviated the chronic stress-induced anti-OVA IgG reductions in vaccination responses.

Exercise, Immunity, and Illness

It is generally accepted that moderate amounts of exercise improve immune system functions and hence reduce the risk of infection whereas athletes engaged in regular prolonged and/or intensive training have a higher than “normal” incidence of minor infections, especially of the upper respiratory tract (URT, e.g., common cold and influenza). This is likely related to regular acute (and possibly chronic) periods of exercise-induced changes in immune function. URT infections can compromise performance directly if suffered shortly before or during competition or indirectly if suffered at other times via effects on training and/or physiological adaptations. This chapter covers the effects of exercise (acute and chronic), both positive and negative, on immune function and consequent infection risk, and considers the current state-of-the-art for monitoring and assessing this in athletes.

Changes in cytokines, leptin, and IGF-1 levels in overtrained athletes during a prolonged recovery phase: A case-control study

We investigated how cytokines are implicated with overtraining syndrome (OTS) in athletes during a prolonged period of recovery. Plasma IL-6, IL-10, TNF-α, IL-1β, adipokine leptin, and insulin like growth factor-1 (IGF-1) concentrations were measured in overtrained (OA: 5 men, 2 women) and healthy control athletes (CA: 5 men, 5 women) before and after exercise to volitional exhaustion. Measurements were conducted at baseline and after 6 and 12 months. Inflammatory cytokines did not differ between groups at rest. However, resting leptin concentration was lower in OA than CA at every measurement (P < 0.050) but was not affected by acute exercise. Although IL-6 and TNF-α concentrations increased with exercise in both groups (P < 0.050), pro-inflammatory IL-1β concentration increased only in OA (P < 0.050) and anti-inflammatory IL-10 was greater in CA (P < 0.001). In OA, exercise-related IL-6 and TNF-α induction was enhanced during the follow-up (P < 0.050). IGF-1 decreased with exercise in OA (P < 0.050); however, no differences in resting IGF-1 were observed. In conclusion, low leptin level at rest and a pro-inflammatory cytokine response to acute exercise may reflect a chronic maladaptation state in overtrained athletes. In contrast, the accentuation of IL-6 and TNF-α responses to acute exercise seemed to associate with the progression of recovery from overtraining.

Evidence of a Redox-Dependent Regulation of Immune Responses to Exercise-Induced Inflammation

We used thiol-based antioxidant supplementation (n-acetylcysteine, NAC) to determine whether immune mobilisation following skeletal muscle microtrauma induced by exercise is redox-sensitive in healthy humans. According to a two-trial, double-blind, crossover, repeated measures design, 10 young men received either placebo or NAC (20 mg/kg/day) immediately after a muscle-damaging exercise protocol (300 eccentric contractions) and for eight consecutive days. Blood sampling and performance assessments were performed before exercise, after exercise, and daily throughout recovery. NAC reduced the decline of reduced glutathione in erythrocytes and the increase of plasma protein carbonyls, serum TAC and erythrocyte oxidized glutathione, and TBARS and catalase activity during recovery thereby altering postexercise redox status. The rise of muscle damage and inflammatory markers (muscle strength, creatine kinase activity, CRP, proinflammatory cytokines, and adhesion molecules) was less pronounced in NAC during the first phase of recovery. The rise of leukocyte and neutrophil count was decreased by NAC after exercise. Results on immune cell subpopulations obtained by flow cytometry indicated that NAC ingestion reduced the exercise-induced rise of total macrophages, HLA⁺ macrophages, and 11B⁺ macrophages and abolished the exercise-induced upregulation of B lymphocytes. Natural killer cells declined only in PLA immediately after exercise. These results indicate that thiol-based antioxidant supplementation blunts immune cell mobilisation in response to exercise-induced inflammation suggesting that leukocyte mobilization may be under redox-dependent regulation.

A Systematic Review of the Acute Effects of Exercise on Immune and Inflammatory Indices in Untrained Adults

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of global mortality. Although the incidence may be reduced with regular exercise, the health benefits of a single bout of exercise on selected CVD risk factors are not well understood. The primary objective of this review is to consider the transient effects of exercise on immune (neutrophil count) and inflammatory (interleukin-6 [IL-6], C-reactive protein [CRP]) markers in untrained adults.

METHODS

MEDLINE, EMBASE, CINAHL, Sports Discus and Cochrane were searched for relevant studies published from January 1946 to May 2013. Randomised controlled or crossover studies which measured any of these parameters in untrained but otherwise healthy participants in the 48 h following about of exercise, less than 1 h in duration were included.

RESULTS

Ten studies met the inclusion criteria. The results indicate a single bout of aerobic or resistance exercise of moderate to high intensity promotes an increase in IL-6 (145 %) and neutrophil counts (51 %). It appears that 30-60 min of moderate to high intensity exercise is necessary to elicit such changes although variables such as the mode, intensity and pattern of exercise also affect the response. The acute response of CRP within the included studies is equivocal.

CONCLUSIONS

Although responses to CRP are inconsistent, a single bout of exercise can increase the activity of both circulating IL-6 and neutrophil counts in untrained adults. These immune and inflammatory responses to a single bout of exercise may be linked to a range of health benefits.

Nutritional and Physical Activity Interventions to Improve Immunity

Physical activity and nutrition are important in a healthy lifestyle with potential benefits to immunity often overlooked. Infection of the upper respiratory tract, and the associated symptoms, are the most frequent presentations to general practitioners and may have significant economic and social impact. In this review, we consider the role of physical activity and nutrition in improving immunity. Evidence suggests that regular moderate activity is particularly beneficial for immune enhancement and reducing the risk of infection. We also discuss some nutritional strategies. Unfortunately, the evidence for many is weak. Avoiding nutritional deficiencies seems the most pragmatic recommendation. This can be achieved with a balanced diet. Including a variety of fruits and vegetables may help ensure adequate intake of essential nutrients with little risk of excess intake of any single nutrient. Supplementation with individual nutrients is generally not recommended. Multinutrients may be beneficial for those with a preexisting deficiency but not if normal dietary intake is sufficient. Further benefit may be gained from some supplements including probiotics, bovine colostrum, and some plant-derived products (Echinacea, black elderberry, and some polyphenols) but only in specific situations/contexts. Individuals should consider their personal needs, use caution, and avoid the indiscriminate use of supplements.

Induced mild systemic inflammation is associated with impaired ability to improve cognitive task performance by practice

Elevated inflammatory levels are linked to poorer cognition, but experimental confirmation is lacking. This report examined associations between cognitive performance and inflammation induced by exercise and vaccination. Thirty-six (exercise N = 18, vaccination N = 18) healthy males completed a paced auditory serial addition test (PASAT), which is a multifaceted measure of cognitive function. The task was completed in placebo and elevated inflammation states. Improvements in PASAT performance were related to inflammation. In the exercise study, IL-6 during the first PASAT negatively correlated with PASAT improvement (p = .022). In the vaccination study, increases in C-reactive protein between PASATs correlated with reduced PASAT improvement (p < .001). Inflammation was linked to reduced improvements in cognitive performance. Further research should identify the specific cognitive functions affects and the underlying mechanisms.

Eccentric-exercise induced inflammation attenuates the vascular responses to mental stress

Mental stress has been identified as a trigger of myocardial infarction (MI), with inflammation and vascular responses to mental stress independently implicated as contributing factors. This study examined whether inflammation moderates the vascular responses to mental stress. Eighteen healthy male participants completed a stress task under two counter balanced conditions. In the exercise condition, a morning bout of eccentric exercise (12×5 repetitions of unilateral eccentric knee extension at 120% intensity of concentric one repetition maximum) was used to increase levels of inflammatory-responsive cytokines during an afternoon stress session scheduled 6h later. In the control condition, participants sat and relaxed for 45min, 6h prior to the afternoon stress session. Forearm blood flow, calf blood flow (measured in the leg which completed the exercise task), blood pressure, heart rate and cardiac output were assessed at rest and in response to mental stress. As expected, interleukin-6 was higher (p=.02) 6h post exercise, i.e., at the start of the stress session, as compared to the no-exercise control condition. Mental stress increased forearm blood flow, calf blood flow, blood pressure, heart rate, and cardiac output in both conditions (p's<.001). Stress-induced calf blood flow was attenuated in the exercise condition compared to the control condition (p<.05) which was not the case for forearm blood flow. This study found that the inflammatory response to eccentric exercise attenuated the vascular responses to mental stress locally at the site of eccentric exercise-induced inflammation. The observed impairment in vascular responses to stress associated with increased levels of inflammation suggests a mechanism through which inflammation might increase the risk for MI.

Vaccination response following aerobic exercise: can a brisk walk enhance antibody response to pneumococcal and influenza vaccinations?

High intensity acute exercise at the time of vaccination has been shown to enhance the subsequent antibody response. This study examines whether an acute moderate intensity aerobic intervention prior to vaccination can enhance antibody response to pneumonia and half dose influenza vaccination. Sixty young (age (SD)=22.0 (6.1) years) and 60 older (age (SD)=57.5 (6.5) years) adults attended the laboratory on two separate occasions. At the first session, baseline antibody titres were determined, before participants completed either a brisk walk around campus at >55% of their age-predicted heart rate maximum, or a resting control condition, for 45 min. After the intervention, all participants received a full-dose pneumococcal vaccination and a half-dose influenza vaccination. Four weeks later, participants returned for a follow up blood sample. Multivariate ANOVA revealed an increase in total antibody titres against the influenza vaccine (F((12,106))=25.76, p<.001, η(2)=.75) and both the IgM (F((12,106))=17.10, p<.001, η(2)=.66) and IgG (F((12,106))=25.76, p<.001, η(2)=.75) antibody titres against the pneumococcal vaccine. However, there were no significant Time×Group interactions (p's all >.15), indicating that a 45 min brisk walk prior to vaccination did not affect antibody response to either the influenza or pneumonia vaccine. The results suggest that higher intensity exercise is necessary to augment antibody response to vaccination.

Acute Exercise as an Adjuvant to Influenza Vaccination

Acute exercise prior to vaccine administration can improve the immune response. Animal data are now supported by human trials, which have shown that immune responses are enhanced by a bout of acute exercise before innoculation; this effect is particularly prominent in vaccines that normally produce weak immune responses. Although there remain many aspects of this phenomenon to be investigated, including task characteristics such as duration and form of exercise, it appears that even a moderate bout of exercise of the muscles into which vaccine will be administered can enhance the antibody response. In this review, the authors will summarize the animal and human literature and discuss the investigation of potential mechanisms of acute exercise–induced immunoenhancement.

Exercise intensity does not influence the efficacy of eccentric exercise as a behavioural adjuvant to vaccination

Acute exercise prior to vaccination can improve the antibody response to influenza vaccination. However, both the optimal exercise protocol and the mechanisms underpinning this adjuvant effect remain unclear. The aim of the current study was to determine whether exercise intensity influenced the efficacy of the intervention. One hundred and sixty healthy young adults were randomly assigned to a resting control group or one of three intervention groups, who exercised at an intensity of 60%, 85%, or 110% of their pre-determined concentric one repetition maxima. The exercise groups performed 50 repetitions of the eccentric portion of both bicep curl and lateral raise movements. All participants then immediately received a reduced dose (50% recommended dose) influenza vaccine. Antibody titres to the three viral strains contained in the vaccine were measured at baseline and at 28 days post-vaccination. Compared to the control group, exercise enhanced the antibody response to the least immunogenic of the three strains (B/Florida). In addition, the exercise groups showed an augmented response to the A/Uruguay strain compared to control; however, this effect was observed only in men. The intervention had no effect on the antibody responses to the most immunogenic strain, A/Brisbane. Finally, antibody responses were unrelated to the intensity of the exercise bout. In conclusion, our findings provide further evidence of exercise as an adjuvant to enhance vaccination responses. The results further show that responses to the low-immunogenic antigens are particularly responsive to augmentation by acute eccentric exercise.

The effects of vaccine timing on the efficacy of an acute eccentric exercise intervention on the immune response to an influenza vaccine in young adults

An acute bout of exercise prior to vaccination can improve the antibody and cell-mediated responses to influenza vaccination. The mechanisms underpinning this adjuvant effect remain unclear, and further investigation to determine the optimal exercise protocol is warranted. The aim of the current study was to determine whether exercise augmented the immune response to vaccination, and whether the timing of exercise relative to vaccination affected the efficacy of the intervention. One hundred and fifty-six (76 men) healthy participants were randomly assigned to a control group or one of three intervention groups who exercised immediately, 6h or 48 h prior to administration of a standard trivalent influenza vaccine. The exercise groups performed 50 repetitions of the eccentric portion of both the bicep curl and lateral raise movements at an intensity eliciting 85% of each participant's pre-determined concentric one repetition maxima. Antigen-specific serum antibody titres were measured at baseline and 28 days post-vaccination as indicators of the humoral response. All three viral strains elicited strong antibody responses; however, eccentric exercise did not further augment any antibody responses compared to the control group. Cell-mediated immunity at 28 days post-vaccination was determined by measuring the IFN-gamma response to in vitro stimulation of the blood with whole vaccine. There were no differences in cell-mediated immunity among the groups. Although these null findings were unexpected, they are consistent with previous research showing that exercise-induced immunoenhancement was only observed when the control group had relatively poor responses. In conclusion, it is likely that the robust immune responses to the vaccine observed in this study may have limited any further immune enhancement by exercise.