The purpose of this study was to compare the effects of two similar high-intensity intermittent exercises (HIIE) but different volume 1.25 km (HIIE1.25) and 2.5 km (HIIE2.5) on inflammatory and BDNF responses. Ten physically active male subjects (age 25.22 ± 1.74 years, body mass 78.98 ± 7.31 kg, height 1.78 ± 0.06 m, VO2peak 59.94 ± 9.38 ml·kg·min−1) performed an incremental treadmill exercise test and randomly completed two sessions of HIIE on a treadmill (1:1 min at vVO2max with passive recovery). Blood samples were collected at rest, immediately and 60-min after the exercise sessions. Serum was analyzed for glucose, lactate, IL-6, IL-10, and BDNF levels. Blood lactate concentrations was higher immediately post-exercise compared to rest (HIIE1.25: 1.69 ± 0.26–7.78 ± 2.09 mmol·L−1, and HIIE2.5: 1.89 ± 0.26–7.38 ± 2.57 mmol·L−1, p < 0.0001). Glucose concentrations did not present changes under the different conditions, however, levels were higher 60-min post-exercise than at rest only in the HIIE1.25 condition (rest: 76.80 ± 11.14–97.84 ± 24.87 mg·dL−1, p < 0.05). BDNF level increased immediately after exercise in both protocols (HIIE1.25: 9.71 ± 306–17.86 ± 8.59 ng.mL−1, and HIIE2.5: 11.83 ± 5.82–22.84 ± 10.30 ng.mL−1). Although both exercises increased IL-6, level percent between rest and immediately after exercise was higher in the HIIE2.5 than HIIE1.25 (30 and 10%; p = 0.014, respectively). Moreover, IL-10 levels percent increase between immediately and 60-min post-exercise was higher in HIIE2.5 than HIIE1.25 (37 and 10%; p = 0.012, respectively). In conclusion, both HIIE protocols with the same intensity were effective to increase BDNF and IL-6 levels immediately after exercise while only IL-10 response was related to the durantion of exercise indicanting the importance of this exercise prescription variable.

Purpose: To compare the acute and chronic effects of high intensity intermittent training (HIIT) and steady state training (SST) on the metabolic profile and inflammatory response in physically active men.Methods: Thirty recreationally active men were randomly allocated to a control group (n = 10), HIIT group (n = 10), or SST group (n = 10). For 5 weeks, three times per week, subjects performed HIIT (5 km 1-min at 100% of maximal aerobic speed interspersed by 1-min passive recovery) or SST (5 km at 70% of maximal aerobic speed) while the control group did not perform training. Blood samples were collected at fasting (~12 h), pre-exercise, immediately post, and 60 min post-acute exercise session (pre- and post-5 weeks training). Blood samples were analyzed for glucose, non-ester fatty acid (NEFA), and cytokine (IL-6, IL-10, and TNF-α) levels through a three-way analysis (group, period, and moment of measurement) with repeated measures in the second and third factors.Results: The results showed an effect of moment of measurement (acute session) with greater values to TNF-α and glucose immediately post the exercise when compared to pre exercise session, independently of group or training period. For IL-6 there was an interaction effect for group and moment of measurement (acute session) the increase occurred immediately post-exercise session and post-60 min in the HIIT group while in the SST the increase was observed only 60 min post, independently of training period. For IL-10, there was an interaction for training period (pre- and post-training) and moment of measurement (acute session), in which in pre-training, pre-exercise values were lower than immediately and 60 min post-exercise, in post-training period pre-exercise values were lower than immediately post-exercise and immediately post-exercise lower than 60 min post, it was also observed that values immediately post-exercise were lower pre- than post-training, being all results independently of intensity (group).Conclusion: Our main result point to an interaction (acute and chronic) for IL-10 showing attenuation post-training period independent of exercise intensity.

Purpose Interleukin 10 (IL‐10) is a cytokine that plays a critical role with potent anti‐inflammatory properties when produced during exercise, limiting host immune response to pathogens and preventing tissue damage. The purpose of this systematic review was to assess the response of IL‐10 after acute exercise session in healthy adults. Methods Databases of Ovid Medline (1978–2016), CINAHL (1998–2016), EMBASE (2003–2016), SportDiscus (1990–2016), and Web of Science library (1990–2016) were carefully screened. Clinical trials comparing exercise types in healthy individuals were included for pooled analysis. The trials of exercise were methodologically appraised by PEDro Scale. Results Twelve randomized controlled and crossover trials containing 176 individuals were identified for inclusion. The Kruskal‐Wallis test showed no significant differences between type of exercise and the corresponding values in IL‐10 [X2(4) = 2.878; p = 0.449]. The duration of exercise was significantly correlated with increase in IL‐10 changes (Pearson's r = 1.00, 95%CI: 0.015–0.042, p < 0.0001) indicating that 48% of the variation in IL‐10 levels can be explained by the duration of the exercise performed. In addition, despite a linear increase, we did not find a significant correlation with the intensity of exercise and IL‐10 changes (Pearson's r = 0.218, 95%CI: −0.554–0.042, p < 0.035). Conclusion Overall, the duration of the exercise is the single most important factor determining the magnitude of the exercise‐induced increase of plasma IL‐10.

The aim of this study was to compare heart rate variability (HRV) recovery after two iso-volume (5 km) exercises performed at different intensities. 14 subjects volunteered (25.17±5.08 years; 74.7±6.28 kg; 175±0.05 cm; 59.56±5.15 mL·kg(-1)·min(-1)) and after determination of peak oxygen uptake (VO2Peak) and the speed associated with VO2Peak (sVO2Peak), the subjects completed 2 random experimental trials: high-intensity exercise (HIE - 1:1 at 100% sVO2Peak), and moderate-intensity continuous exercise (MIE - 70% sVO2Peak). HRV and RR intervals were monitored before, during and after the exercise sessions together with, the HRV analysis in the frequency domains (high-frequency - HF: 0.15 to 0.4 Hz and low-frequency - LF: 0.04 to 0.15 Hz components) and the ratio between them (LF/HF). Statistical analysis comparisons between moments and between HIE and MIE were performed using a mixed model. Both exercise sessions modified LFlog, HFlog, and LF/HF (F=16.54, F=19.32 and F=5.17, p<0.05, respectively). A group effect was also found for LFlog (F=23.91, p<0.05), and HFlog (F=57.55, p< 0.05). LF/HF returned to resting value 15 min after MIE exercise and 20 min after HIE exercise. This means that the heavy domain (aerobic and anaerobic threshold) induces dissimilar autonomic modification in physically active subjects. Both HIE and MIE modify HRV, and generally HIE delays parasympathetic autonomic modulation recovery after iso-volume exercise.

respectively, p < 0.05

The aim of this study was to compare heart rate variability (HRV) recovery after 2 sessions of high-intensity intermittent exercise at different volumes (1.25 km [HIIE] and 2.5 km [HIIE]). 13 participants determined their maximal aerobic speed (MAS) and completed 2 HIIE (1:1 at 100% MAS) trials. The heart rate was recorded before and after each session. HRV indicators were calculated according to time (RMSSD and SDNN) and frequency (LF, HF and LF/HF ratio) domains. SDNN and RMSSD presented effect of test (F=20.97; p<0.01 and F=21.00; p<0.01, respectively) and moment (F=6.76; p<0.01 and F=12.30; p<0.01, respectively), without interaction. Even though we did not find an interaction effect for any HRV variables, the HIIE presented a delay of only 5 min in HRV recovery, when compared to HIIE. However, the effects of the test (SDNN, RMSSD, LF-log, and HF-log) indicate higher autonomic stress during the entire recovery period. These findings may indicate that exercise volume interferes with HRV recovery. If so, physically active subjects may choose a lower volume exercise (i. e., HIIE) in order to promote similar physical fitness adaptations with lower loading on autonomic modulation.

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Interleukin-10 (IL-10) inhibits pro-inflammatory cytokine production in blood leukocytes - an effect mediated by signal transducer and activator of transcription 3 (STAT3) activation. To examine potential sex-based differences in IL-10's anti-inflammatory function, we treated whole blood from healthy males and females (n=16 each; age: 28±6 years; body mass index: 23.5±2.3 kg/m2) with increasing concentrations of IL-10 (1-100 ng/mL) and quantified changes in phosphorylated STAT3 (pSTAT3) in CD14+ monocytes and CD4+ lymphocytes via flow cytometry. In parallel, liposaccharide (LPS)-stimulated whole-blood cultures were used to assess sex-based differences in IL-10's ability to inhibit tumour necrosis factor (TNF)-α production. IL-10 concentration-dependently increased pSTAT3 mean fluorescent intensity (MFI) in CD14+ and CD4+ cells (main effects of concentration, P<0.01) with males exhibiting larger changes in pSTAT3 MFI in both cell types (main effects of sex, P<0.01). Accordingly, IL-10-mediated inhibition of TNF-α production was more pronounced in males (main effect of sex, P<0.01) with changes in other monocyte-derived cytokines (IL-1b, IL-1RA, IL-15) also supporting a sexual dimorphism in IL-10 action (P<0.05). These sex-based differences were not explained by differences in circulating plasma IL-10 concentrations, basal IL-10 receptor expression in unstimulated CD14+ and CD4+ cells, nor the basal expression of IL-10 signaling proteins (STAT3, SHIP1, p38 MAPK) in unstimulated peripheral blood mononuclear cells. We conclude that IL-10's anti-inflammatory function differs between male and female blood leukocytes ex vivo. This sexual dimorphism should be considered in future work investigating IL-10's anti-inflammatory action in humans as it may represent a mechanism contributing to sex differences in overall immune function.