Differences in the Impact of Various Types of Exercise on Irisin Levels: A Systematic Review and Meta-Analysis.

Background: Irisin, a myokine that is responsive to exercise, induces significant changes in subcutaneous adipose tissue. By promoting the browning of white fat tissue, it enhances energy expenditure, thereby addressing overweight and obesity. This systematic review and meta-analysis aimed to compare the effects of different types of physical exercises on irisin levels in overweight and obese adults. Methods: Specifically, the review focused on studies involving obese or overweight individuals who participated in exercise training for a minimum of 8 weeks, with measured and reported changes in serum irisin levels compared to a control group. Data were collected from four databases (Google Scholar, ISI Web of Science Core Collection, PubMed, and Scopus). The risk of bias was assessed using the Begg and Egger tests, and the results were synthesized. Results: Initial searches identified 560 titles, out of which only seven met the criteria for inclusion in the systematic review. Statistical analysis demonstrated a significant increase in serum irisin concentration (SMD = 0.957, P = 0.005) among obese and overweight individuals who engaged in exercise, compared to the passive control group. High-intensity interval training (HIIT) (SMD = 1.229, P < 0.001) had a more pronounced effect on increasing serum irisin levels than other exercise protocols. Furthermore, the effectiveness of exercise varied based on the participants' weight status (significant changes for overweight individuals; P < 0.001 and insignificant changes for obese individuals; P = 0.1), age (significant changes for those under 40 years old; P < 0.001 and insignificant changes for those over 40 years old; P = 0.322), and gender (significant changes for men; P < 0.001 and insignificant changes for women; P = 0.285). Conclusions: Consequently, exercise can elevate serum irisin levels, leading to alterations in adipose tissue phenotype and thermogenesis, ultimately contributing to weight reduction in obese and overweight individuals.

Studying the Effect of Garlic Consumption and Endurance Training on Serum Levels of Some Pro-and Anti-inflammatory Cytokines in Female Mice with Breast Cancer - A Randomized Trial.

Background: This study aimed to determine the effect of garlic consumption and endurance training on the serum levels of some pro-inflammatory and anti-inflammatory cytokines in female mice with breast cancer. Methods: This study is an experimental research randomly conducted on 32 female BALB/c mice divided into 4 equal groups (N = 8), including: Cancer Control (CC), Garlic Supplementation (GS), Endurance Training (ET), Endurance Training + Garlic Supplementation (ET + GS). One million cancerous cells were injected to all mice's upper right thigh using the subcutaneous injection method. Exercise groups performed endurance training for 8 weeks (5 days a week.(Garlic supplement groups received 1 ml of the garlic extract orally per kilogram of body weight. The control groups -were not given any task, activity or exercise during the research. At the end of the research, all the mice were anesthetized, and their blood samples were collected. Results: The period of 8-week simultaneous endurance exercise and consumption of garlic supplement significantly decreased the serum level of interleukin-6 (F = 75 P = 0.00), interleukin-8 (F = 97.9 P = 0.00), and interleukin-17 (F = 95.7 P = 0.00), and increased the serum level of interleukin-10 (F = 50.4 P = 0.00). Conclusions: Along with other existing methods, reduction of inflammatory factors, endurance exercises and consumption of garlic supplement have been proved to be an extremely effective treatment for breast cancer patients.

Effects of 8 Weeks of High-Intensity Interval Training and Spirulina Supplementation on Immunoglobin Levels, Cardio-Respiratory Fitness, and Body Composition of Overweight and Obese Women.

Our study examined the effect of 8 weeks of high-intensity interval training (HIIT) and spirulina supplementation on the humoral immunity, cardio-respiratory fitness, and body composition of overweight and obese women. Thirty sedentary women (height: 161.7 ± 2.8 cm, body mass: 75.8 ± 8.4 kg, body mass index [BMI]: 28.8 ± 2.5 kg/m2, age: 25.1 ± 6.7 years) were divided into three groups: placebo with HIIT group, spirulina group (SG), or combined group (CG). Exercise groups performed HIIT for 8 weeks, with three sessions per week and four to seven repetitions in each session of 30 s running and 30 s walking; the intensity was established at 90% of the maximum heart rate. Supplementation groups received 6 g of spirulina powder per day. Fasting blood samples were collected before and after 8 weeks to determine the concentrations of immunoglobulins (IgA and IgG). There was a significant group-by-time interaction for fat free mass (FFM; p = 0.001, f = 8.52, ηp2 = 0.39) and IgA (p = 0.036, f = 3.86, ηp2 = 0.22). The post hoc analysis revealed that CG reduced FFM significantly (p = 0.012, g = -0.55) after training. CG and SG showed significantly greater IgA concentrations after 8 weeks (p = 0.02, g = 0.70 and p = 0.001, g = 0.34, respectively). We conclude that spirulina supplementation with HIIT affects the body composition (lower FFM) but also boosts IgA, which plays an important role in the immune system.

The Effects of 8-Week Resistance and Endurance Trainings on Bone Strength Compared to Irisin Injection Protocol in Mice.

BACKGROUND: Osteoporosis is a prevalent elderly complication that is characterized by decreased bone mineral density and increased fracture risk because of dysregulation in bone mineralization and resorption. Physical activity can enhance bone strength by exerting mechanical forces and myokines. Irisin is a myokine that is increased following physical exercise and can affect bones. In this study, 8 weeks of resistance and endurance exercises are applied in mice compared to irisin injection to assess the contribution of the protocols and this myokine to bone strength. MATERIALS AND METHODS: Thirty-five male NMRI mice were separated into five groups; control, placebo, irisin injection, resistance exercise, and endurance exercise. 8-week of exercise protocols and irisin injection protocol (100 µg/kg/week) was applied. Plasma irisin concentration and bone strength were measured using enzyme-linked immunoassay and 3-point bending assay, respectively. Statistical analyses were done through one-way ANOVA and Tukey test, and P < 0.05 was considered the significant difference. RESULTS: Serum irisin concentration and bone strength in resistance exercise and irisin-injected groups were significantly higher than control and placebo groups (P < 0.0001). Serum irisin concentration, but not bone strength, of the endurance exercise group was also significantly higher than control and placebo groups (P < 0.0001) but lower than resistance and irisin-injected groups. CONCLUSION: Resistance exercise and irisin injection, but not endurance exercise, are likely to be effective in increasing bone strength. There may be a threshold for plasma irisin level to affect bones which the applied protocols of irisin injection and resistance exercise but not endurance exercise can reach.

Monitoring collegiate soccer players during a congested match schedule: Heart rate variability versus subjective wellness measures.

The aims of this study were a) to examine within-group changes of wellness and heart rate variability measures and b) to compare their sensitivity to a congested match schedule in collegiate soccer players (n = 8). Wellness (Hooper index and its subsets) and heart rate variability (Ln rMSSD, SDNN) measures were assessed after selected low-load (training sessions) and high-load (a congested match schedule) phases. Session rating of perceived exertion (sRPE) was computed for training and match sessions. A very likely large difference in accumulated sRPE was observed between low-load and high-load phases (+148.4%, 90% confidence interval CI [87.3; 229.5%]); effect size, ES, 2.16 [1.49; 2.82]. While the Hooper index showed an almost certainly moderate increase (+49.8%, [33.9; 67.5%]), ES, 1.05 [0.76; 1.34], heart rate variability measures (i.e., Ln rMSSD and SDNN) only changed with a possible trivial effect (range -2.1; 8.2%, [-7.1; 16.7%]), ES, -0.15; 0.15 [-0.50; 0.44]. The Hooper index showed a moderately higher sensitivity than Ln rMSSD to a congested match schedule (34.7%, [26.9; 41.6%], ES, 0.81 [0.60; 1.03]). Relationships between changes in the Hooper index and some of its subsets (∆Hooper index, ∆sleep, and ∆fatigue), with changes in mean sRPE (∆sRPE) were very large (range r = 0.72; 0.89). However, small associations were observed between changes in heart rate variability (∆Ln rMSSD, and ∆SDNN) and ∆sRPE (range r = -0.21; 0.10). This study suggests the use of subjective wellness indices, instead of heart rate variability measures, to monitor collegiate soccer players during congested match schedules.

Can Resistance Exercise Alter Irisin Levels and Expression Profiles of FNDC5 and UCP1 in Rats?

BACKGROUND: Irisin is a new myokine secreted from the skeletal muscle and appears to affect the metabolism of adipose tissue. OBJECTIVES: The mechanisms of cellular and molecular identification by which exercise training exerts its benefits remain unclear and are under investigation. METHODS: We examined the effect of 8-week resistance exercise on plasma irisin levels and expression profiles of muscle FNDC5 and subcutaneous adipose tissue UCP1 in male rats. Sixteen adult male rats were divided into two groups, control (n = 8) and exercise training (n = 8) groups. The training group received exercise for 3 days/week on a specific ladder (120 cm height) with a carrying load of 50% of body weight, which was attached to their tails. RESULTS: The weight of the load was gradually increased during the training sessions, ultimately reaching 200% of the body weight of rats in the final week. There were three sets of five repetitions with a 3-min rest between each set of exercise sessions and 1 minute between repetitions. Plasma irisin levels and relative mRNA expression of the genes UCP1 and FNDC5 were assessed. The results demonstrated a significant increase in the irisin levels after 8 weeks of resistance exercise (P < 0.001, t = 4.48). The relative expression of FNDC5 (P < 0.001, t = 6.18) and UCP1 genes (P < 0.001, t = 13.91) was also significantly increased. CONCLUSIONS: Therefore, we can conclude from this study that resistance exercise may improve body composition possibly through increased thermogenesis in white adipose tissue through the secretion of irisin.