نشریه سوخت و ساز و فعالیت ورزشی
سال هشتم شماره 1 (بهار و تابستان 1397)

One of the most important and prevalent disorders in elderly people is age-related muscular atrophy or Sarcopenia. Sarcopenia is associated with a significant reduction in muscle strength and volume. The purpose of this study was to investigate the effect of moderate and high intensity resistance training on serum levels of myostatin and IGF-1 in elderly rats thirty male Wistar rats (23 months old) were randomly divided into two experimental and control group including moderate intensity resistance training (n = 10), high intensity resistance training (n = 10) and the control group (n = 10). Resistance training included 8 weeks of climbing a ladder with high intensity (80% MVCC) and moderate intensity (60% of MVCC) and 5 days a week. After completing training, serum concentration of IGF-1 and myostatin were measured using the ELISA method. Myostatin concentration in decreased in high (916.5±43.1) and moderate (958.8±36.9) intensity resistance groups and IGF-1 increases in high (156.3±15.5) and moderate (141.8±7.4) intensity resistance groups (p<0.05). Also, there was significant difference between the IGF-I levels in high and moderate resistance training (p=0.009). However, there was no significant difference in myostatin level between groups. It seems that resistance training with moderate and high intensity can be change  the resting levels of factors associated with muscular atrophy in elderly rats. However, there id further need to evaluate in human participants.

The aim of this study was to investigate the effects of aerobic training on serum Chemerin levels, inflammatory and cardio-metabolic risk factors in factors in midlife males complicated with metabolic syndrome. twenty six males with local Met criteria (age: 54.69±3.67 yrs., BMI: 31.21±1.23 kg/m2 and Vo2peak: 20.38±4.49 ml/kg.min) were randomly divided into aerobic training (n=14) and control (n=12) groups. Throughout eight weeks of training (3 sessions /week) the training load were increased from 15-20 min at 50-55% of HRpeak (end GXT heart rate) to 35-40 min at 60-65%. Blood samples were collected at baseline and 48 h after the intervention. Aerobic training induced significant reductions in all (except for HDL and Vo2peak) the investigated variables (P<0.05). At baseline, body weight and age were recognized as the most important predictors of serum Chemerin (P<0.05). Throughout the intervention period, the changes in blood glucose and CRP were the significant predictors of the concomitant changes in serum Chemerin levels (P<0.01), and the changes of Chemerin were the only predictor of the accompanying changes in CRP level (P<0.03). Chemerin reduces synchronously with the beneficial effects on metabolic and inflammatory indices as well as aerobic fitness level to be likely as the results from blood glucose and CRP modifications induced by aerobic training. However; more research remains to be done because of a little available evidence and limitations from this study.
 
Keywords: Aerobic training, Chemerin, CRP, Metabolic risk factor

Dipeptidyl-peptidase-4 (DPP-4) has been proposed as a bridge between obesity and insulin resistance (IR). The aim of this study was to investigate the changes in serum levels of DPP-4 and HOMA2-IR after eight weeks of interval and continuous-walking in 9-11 year-old obese girls. thirty two-obese girls (age: 9.62±0.75 years and BMI-percentile: 97.38±1.40%) volunteered in this study and were assigned to interval (n=12), continuous (n=11) and control (n=9) groups. The training were performed for 8-weeks, 3-sessions per week (30-min walking in the continuous and interval groups with 60-75%HRmax and 70-85%HRmax, respectively). Interval-walking included 2-min of walking and 1-min of active rest. After 10-hours of fasting, blood sampling was performed before the beginning of training and 72-hours after the last session. The paired t-test was used to examine the within-group changes. Eight weeks of continuous and interval training did not significantly change the levels of DPP-4, insulin, glucose, and HOMA2-IR compared to the control group. Compared to the control group, the interval training resulted in improvement of the body weight, BMI, and BMI percentile (p=0.004, p=0.019, p=0.022), while the BMI only tended to decrease in the continuous training group (p=0.077). It seems that the improvement of the body composition due to the protocol used in this study was not sufficient to make significant changes in the HOMA2-IR and DPP-4 in early-pubertal obese girls.

Aging is associated with the reduction of interleukin-15 levels (IL-15), muscles atrophy and consequently loss of muscular strength. The purpose of present study was to investigate the effect of 8-weeks resistance training with Thera-band on the serum levels of IL-15, balance and muscle strength in elderly women. In a quasi-experimental study, 18 elderly women (age: 73.66 ±4.79 years; BMI: 25.6±3.25) randomly were divided into following groups: experimental (n=10) and control (n=8). Resistance training program included 40 min workouts with Thera-Band for 8 weeks and 3 times per week. Forty eight hours before and after the training protocol balance, hand grip and trunk strength were measured using dynamometer, and blood samples were taken in fasted state. Serum levels of IL-15 were assessed by enzyme-linked immunosorbent assay (ELISA). The results showed that the serum levels of IL-15 (P= 0.029), balance (P= 0.003) right hand strength (P= 0.010), left hand strength (P=0.001) and low extremely strength (P=0.001) increased significantly in resistance training with Thera- band group in compared to control group. Based on these findings it could be concluded that Thera-band training may improve the balance in elderly women and there is a relationship between the changes of muscular strength and IL-15 levels.

Soccer due to its own functional characteristics rely more on some physiological factors than other sports. The purpose of this study was to assess the effect of resistance training with emphasis on eccentric phase with and without blood flow restriction and traditional resistance training on blood cortisol, endurance performance and anaerobic power in male soccer players. Forty soccer players were selected and randomly divided into four groups include traditional strength training (n=10), eccentric resistance training with blood flow restriction (n=10), eccentric resistance training without blood flow restriction (n=10) and control (n=10). Blood sampling and tests were taken before and after the eight-week training period. A one-way repeated-measures and Bonferroni post-hoc test was used to compare the groups (P<0.05). The results showed that the minimum, maximum, mean power and endurance performance in all three experimental groups had a significant increase after exercise (P<0.001). There was also a significant difference between the two groups experimental of resistance training eccentric with and without blood flow restriction at minimum power (p<0.05). There was a significant difference between resistance training eccentric with blood flow restriction and the traditional resistance training group at maximum and mean power. However, this effect was not significant for fatigue index (p=0.13) and cortisol hormone (p=0.33). Although the results related to the percentage of changes indicated an improvement in the anaerobic power and endurance function in the traditional exercise group compared to the other two training groups, traditional exercises could still be used.

The purpose of this study was to investigate the relationship between NT-proBNP, galactin-3 and aldosterone variables in endurance skiers after endurance skiing in height.

Twenty four elite endurance skiers (age: 25 years; body fat: 14%) were divided into two groups (Experimental, Control). The skiing program included a skiing route of 8.5 km, a mean time of 65 minutes, and an average intensity of 70-90% of the maximum oxygen consumption. The NT-proBNP values ​​were evaluated by ELISA. A week after skiing, a ride on a treadmill was done with a slope and distance and a similar time with the ski resort. To examine the relationship between the variables studied, Pearson correlation coefficient was used at a significant level of 5% using SPSS version 22 software.

: The results showed that only galatin-3 with NT-ProBNP and NT-ProBNP with aldosterone showed significant correlation in height (P<0.05).

Increasing physiological pressure on the heart caused by exposure to hypoxia and dehydration may lead to changes in the aldosterone and galactin-3 hormone as a fibrotic cell marker.