سعید رضا نوری مفرد

Adiponectin is one of the most well-known adipokines with anti-inflammatory effects that plays an important role in regulating the whole-body metabolism. The aim of this study was to investigate the effect of high-intensity interval training (HIIT) versus moderate intensity continuous training (MICT) on the circulating levels of adiponectin in individuals with and without metabolic disorders.

A systematic search was conducted in the databases of PubMed, Web of Science, Academic Jihad Center and Magiran using the keywords "HIIT" and "adiponectin" to identify Persian and English languages published articles until October 2022. Effect size (SMD) and 95% confidence interval were calculated using CMA2 software. I2 test for calculation of the heterogeneity and visual interpretation of funnel plot test and Egger test for assessment of the publication bias were used.

Data analysis of 28 interventions (24 studies) showed that HIIT resulted in a significant increase in adiponectin [0.40 CI: 0.12 to 0.68), P=0.004]. Also, the data analysis of eight interventions showed that HIIT led to a non-significant increase in adiponectin compared to the MICT [0.41 CI: -0.04 to 0.86), P=0.07].

The findings of the present study showed that HIIT is a suitable and efficient training method to increase adiponectin, especially in people with metabolic disorders.

Green coffee affects lipid profile due to its hypolipidemic bioactive compounds. Green coffee along with resistance training are considered as two possible factors for improving lipid profile. This study aimed to investigate the simultaneous effect of resistance training and green coffee on lipid profile and blood glucose in overweight and obese naval officers.

In this quasi-experimental study, 48 overweight and obese men were randomly assigned to four Resistance Training (R-Ex), Green Coffee (GC), Resistance Training + Green Coffee (R-Ex+GC), and Control (Con) groups. The training was performed in four sessions a week for eight weeks. An amount of 400 mg of green coffee was consumed per day for eight weeks.

The results showed a significant decrease in LDL, TG, and TC in the R-Ex group compared with the GC group. Also, the levels of TG and TC in the R-Ex+GC group had a significant decrease compared with the GC group.

According to the results of this research, both types of intervention, GC supplementation and R-Ex alone can be effective in improving lipid profile and blood glucose in overweight and obese naval officers. In addition, the results of this study indicated that consuming GC and R-Ex at the same time can have more beneficial effects on improving lipid profile in overweight and obese men. In general, performing resistance exercises along with the use of herbal supplements such as GC has beneficial effects on lipid metabolism.

Vascular endothelial growth factor (VEGF) is the most important marker of angiogenesis that may increase in response to exercise. However, the effect of acute exercise on this marker has been reported inconsistently. Therefore, the aim of this systematic review and meta-analysis is to investigate the effect of acute exercise on circulating VEGF in adults.

In order to extract original articles, a comprehensive search was conducted in the databases of PubMed, Scopus, Web of Science, SID, Magiran and Google Scholar until 2023 March 1 for studies investigating the effects of acute exercise on circulating levels of VEGF. The meta-analysis criteria included studies published in Persian and English language journals, studies with human subjects with an average age of more than 18 years, studies investigating the effect of acute exercise, and studies measuring serum or plasma VEGF levels. To determine the effect size, standardized mean differences (SMD) values and 95% confidence intervals (CIs) were calculated using CMA2 software. The level of heterogeneity was assessed using the I2 test and the publication bias was also assessed with Egger's test.  Furthermore, subgroup analysis was performed for health status (with chronic disease and healthy) and type of exercise (aerobic, resistance and high-intensity interval exercise).

In total, 27 articles (49 exercise interventions) including 704 subjects were included in the meta-analysis. The results of data analysis showed that acute exercise did not lead to significant changes in VEGF immediately after exercise compared to baseline [0.17, (CI: -0.05 to 0.40, p=0.14). The results of subgroup analysis based on the health status showed that exercise had no significant effect on VEGF in healthy subjects [SMD: 0.10, p=0.40], while it tended to increase VEGF in patients [SMD: 0.30, p=0.05]. The results of the subgroup analysis based on the type of exercise also showed that resistance exercise [SMD: 0.58, p=0.008] leads to a significant increase and high-intensity interval exercise [SMD: 0.29, p=0.06] leads to a non-significant increase in VEGF, while the effect of aerobic exercise [SMD: 0.009, p=0.95] was not significant.

In general, the findings of this meta-analysis showed that the type of exercise plays an effective role in the responses of VEGF to acute exercise. Resistance and high intensity interval exercise may lead to an increase in circulating VEGF immediately post exercise, while aerobic exercise does not have significant effects. In addition, exercise may increase VEGF in people with metabolic-cardiovascular disease, whereas, it is not effective in healthy individuals.

This study aimed to investigate the effect of High-Intensity Interval Training (HIIT) on serum leptin levels in individuals with and without chronic diseases.

In this research, a systematic search was conducted in Persian and English articles published until December 2022, in Web of Science, Scopus, PubMed, SID, and Magiran databases using relevant keywords. After selecting the desired articles based on the inclusion criteria, a meta-analysis of the results was performed. Effect size (SMD) and 95% confidence interval were calculated using CMA2 software. The I2 test was used to identify the heterogeneity, and for the publication bias, the Funnel Plot test and the Egger test were used. All analyzes were performed using CMA2 software.

The results of data analysis showed that HIIT led to a significant decrease in serum leptin [-0.28 (CI: -0.07 to 0.48, p=0.008)]. Also, the data analysis of 9 interventions showed that there was no significant difference between HIIT and Medium Intensity Continuous Training (MICT) on circulating leptin levels [-0.03 (0.27 to 0.34 CI, p=0.82)]. The results of the subgroup analysis based on the health status of the subjects showed that HIIT resulted in a significant decrease in leptin in individuals with chronic diseases.

HIIT leads to a decrease in circulating leptin levels, especially in individuals with chronic diseases. Despite the lack of significant differences between HIIT and MICT, HIIT is a time-efficient intervention for leptin reduction.

 Type 2 diabetes is associated with increased systemic inflammation that may be increased cardiovascular diseases for which exercise training is a potential therapy. The effects of high intensity interval training (HIIT) on inflammatory markers in Type 2 diabetes patients, however, require further elucidation. We therefore performed a systematic review and meta-analysis to investigate the effect of HIIT on inflammatory markers in Type 2 diabetes patients.

 PubMed, Scopus, and Web of Science were searched up to May 2022 for HIIT vs. Control or only HIIT studies on inflammatory makers i.e. CRP, IL-6 and TNF-α in Type 2 diabetes patients. The search was performed using the HIIT, inflammation and type 2 diabetes keywords. Standardized mean difference (SMD) effect sizes and 95% confidence intervals were calculated using CMA2 software.

Among the 257 extracted studies, 11 studies including 257 participants (143 women and 114 men) with an age range of 44 to 71 years were included in the meta-analysis. HIIT was beneficial for promoting a reduction in TNF-a [-0.62 (95% CI: -1.85 to -0.13), p = 0.01] and CRP [-0.65 (95% CI: -1.21 to -0.08), p = 0.02]. However, there were no significant evidence for an effect of HIIT on IL-6 [-0.31 (95% CI: -0.70 to -0.06), p = 0.10] in Type 2 diabetes patients.

 These results suggest that HIIT could induce improvements inflammatory cytokines as well as CRP in Type 2 diabetes patients.

Metabolic syndrome is associated with an increase in chronic inflammation, in which exercise training may be an effective intervention for the improvement of inflammatory markers. Accordingly, this study aimed to investigate the effect of exercise training on the inflammatory markers of interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), and C-reactive protein (CRP) in patients with metabolic syndrome.

In this study, the PubMed, Scopus, and Web of Science databases were searched during June 2022 for studies addressing the effects of exercise training versus control on inflammatory factors, including IL-6, TNF-α, and CRP. The search keywords were exercise training, inflammation, and metabolic syndrome. Standardized mean difference (SMD) and 95% confidence interval were used to determine the effect size using CMA2.

Twenty-two studies including 779 subjects with metabolic syndrome were included in the meta-analysis. Exercise training significantly decreased TNF-α [-0.74 (CI: -0.24 to -1.24), p=0.003] and CRP [-0.56 (CI: -0.25 to 0.87, p=0.001); however, the effect of exercise training on the decrease of IL-6 was not significant [-0.32 (CI: 0.20 to -0.85), p=0.22].

Exercise training decreases inflammatory markers in patients with metabolic syndrome, which may be a reason for the positive effects of exercise training on improving the metabolic status and cardiovascular health in such patients.

The purpose of this research was to assess the effects of 8-week special exercise training on cardio-respiratory parameters، body composition and basal metabolic rate (BMR) in elite athletes.

For this reason، 7 male boxer of national team (height، 176. 2±22. 3; weight،74. 91±18. 51) were selected. They were evaluated by gas analyzer and body composition analyzerbefore and after the training program about cardiorespiratory variables (including: lactate thresholdoxygen consumption (Vo2@LT)، maximal oxygen consumption (Vo2max)، rest ventilation (VER)، lactate threshold ventilation (VELT)، ventilation in Vo2max conditions [VEVo2max]، lactatethreshold heart rate (HRLT)، and lactate threshold in maximal heart rate (HRLT)، BMR، and bodycomposition variables (such as: weight، fat mass (FM)، body fat percent (BF%)، Body Mass Index (BMI)، Lean Body Mass (LBM)، Muscle Mass (MM)، and Total Body Fluid (TBF). Furthermore،correlation among cardiorespiratory، body composition، and BMR properties was studied.

Results of paired t-test showed that this special exercise training does not have any effect on body composition، although، cardiorespiratory variables had improved (however، in more cases was not significant). In this manner، results from Pearson correlation indicated that some cardiorespiratory variables (such as VE) had been associated with most of body composition parameters. In addition، this correlation exists between BMR and most of the body composition parameters.

In conclusion، our study may demonstrate that such program can be effective on mentioned cardiorespiratory indices especially if training program is extended. However، body composition seemingly is not affected in elite athletes.