Purpose: Due to the mechanistic role of myostatin and follistatin in modulating muscle mass, shifts in the 3 follistatin to myostatin ratio (F: M) may help explain changes in muscular size in response to resistance training 4 (RT). The present study examined whether differential responses in follistatin and myostatin occur based on the 5 amount of active musculature in a RT program in middle-aged men. 6 Methods: Forty middle-aged men (age= 46.5±3.1 years) were randomly assigned to one of 4 groups, upper-body 7 RT (UB; n=10), lower-body RT (LB; n=10), combined RT (UB+LB; n=10) or control (C; n=10). The training 8 protocol consisted of 3 exercise sessions per week for 8 weeks. Blood samples were obtained at baseline and 48 9 hours after the final session of the training program. 10 Results: Muscle mass significantly increased (p˂0.05) following UB= 0.76 ± 0.46 kg, LB= 0.90 ± 0.29 kg, 11 UB+LB= 1.38 ± 0.70 kg, compared to no changes after control. Serum follistatin increased in the LB= 0.24 ± 0.06 12 ng.mL-1 , UB= 0.27 ± 0.17 ng.mL-1 , UB+LB= 0.50 ± 0.18 ng.mL-1 , while serum myostatin decreased in the LB=-13 0.11 ± 0.08 ng.mL-1 and UB+LB=-0.34 ± 0.23 ng.mL-1 , but not UB= 0.07 ± 0.16 ng.mL-1. Further, change in 14 concentration following training was larger between UB+LB and either LB or UB alone for both follistatin and 15 myostatin. 16 Conclusions: Both UB and LB increase muscle mass and alter the F: M ratio, however the change in these 17 endocrine markers is approximately twice as large if UB and LB is combined. The endocrine response to RT of 18 myostatin and follistatin may depend on the volume of muscle mass activated during training.
L-citrulline (L-Cit) is a nonessential amino acid that stimulates nitric oxide (NO) production and improves exercise performance by reducing muscle damage indices; however, the direct benefits of L-Cit on antioxidant markers are unclear. The aim of this study was to examine antioxidant responses to high-intensity interval exercise following acute L-Cit supplementation. Nine young men (21 ± 1 years) participated in a double-blind crossover study in which they received 12 g of L-Cit and placebo (PL) an hour prior to high-intensity interval exercise on two occasions, separated by a seven-day washout period. Blood samples were obtained before (PRE), immediately after (IP), 10 (10P), and 30 min after exercise (30P) from the cubital vein using standard procedures. Serum concentrations of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and NO metabolites (NOx) were measured. The exercise protocol significantly elevated SOD (p = 0.01) and GPx (p = 0.048) from PRE to 10P in the L-Cit group with greater changes than the PL group. CAT concentrations increased IP (p = 0.014) and remained elevated at 10P (p = 0.03) and 30P (p = 0.015) in both the L-Cit and PL conditions. NOx concentrations increased IP (p = 0.05) in the L-Cit group with greater changes than PL group in PRE to IP, PRE to 10P, and PRE to 30P (p < 0.05). Our data indicate that L-Cit supplementation (single 12 g dose pre-exercise) induces improvements in antioxidant markers following a session of high-intensity interval exercise in young men.
Introduction: Menopause seems to be among the factors related to the development of prediabetes and central obesity. Conversely, physical activity may have a major role in reducing metabolic syndrome in women of postmenopausal age. Material and methods: Forty-eight postmenopausal active and sedentary women within the ages of 45-65 years were randomized to four groups: 1) high-intensity concurrent interval exercise (HCI; n = 15), 2) moderate-intensity continuous concurrent exercise (MCC; n = 14), 3) control daily active (CDA; n = 10), and 4) control sedentary (COS; n = 9). The subjects in the preceding training groups exercised three times per week for 50-65 min/session with high/moderate concurrent exercise for 10 weeks. The levels of serum irisin, insulin sensitivity, abdominal fat distribution (visceral and subcutaneous), and total abdominal fat were measured at baseline and post-test. Results: This study showed that the HCI group had a significantly increased serum irisin (p < 0.001), stimulated favorable alterations in insulin sensitivity status (p = 0.003), and significantly decreased subcutaneous, visceral and, total abdominal fat (p < 0.001). Also, the insulin sensitivity status was significantly increased (p = 0.01) and subcutaneous abdominal fat significantly decreased in the MCC group (p = 0.018). However, this study's results did not find a considerable correlation between insulin sensitivity, irisin level, weight loss and abdominal fat distribution. Conclusions: High-intensity concurrent exercise has a greater influence on improving most metabolic-related parameters than moderate-intensity concurrent exercise.
Obesity is a major problem for public health due to weight gain from imbalance between energy intake and energy expenditure. According to published data by World Health Organization (WHO), obesity was increased rapidly from outset of last decades of 1900. Prevalence of obesity is accepted as a socioeconomic challenge in present decade. Based on this topic, in particular since 1980 decade, if this trend cannot be reversed or at least restrained, high levels of obesity will naturally lead to increases in the prevalence of chronic diseases, with enormous economic and personal costs. Epidemiological reports show, in 2008, approximately 35% of adults were overweight (body mass index [BMI] ≥25-29.9kg/m2) (34% men and 35% of women). The worldwide obesity prevalence has increased meaningfully between 1980 and 2008. In 2008, 10% of men and 14% of women in the world were obese (BMI≥30kg/m2), compared with 5% for men and 8% for women in 1980. An estimated 205million men and 297million women over the age of 20 were obese a total of more than half a billion adults worldwide. Since physical activity rates over the past three decades are essentially unchanged or lower, it would seem that increased body mass has limited the weight gain due to increased energy output. As a result, obesity prevention has become an international priority. Changes in life habits and patterns, such as dietary behaviors, advancing in technology, relief, sedentary life, and decrease of lifestyle physical activities, results in an increase of obesity and weight gain among men and women. Obesity is related to increased morbidity and mortality rates due to coronary heart disease (CHD), osteoarthritis, infectious disease and cancers. Excessive body weight, in addition, increases the risk of hypertension, unhealthy lipid profile, menopauses, gallbladder disease, diabetes, some cancers, psychosocial experiences, and many other causes of chronic morbidity. Obesity, in addition, involves major expenditure and therefore represents a socioeconomic health problem of the highest magnitude. It is clear that obesity as worldwide problem results in considerable morbidities and decrease individuals abilities for keep their good health for live. In this review we try that augment this history argument, epidemically and represent the relation between physical activities and weight control among men and women. body fatness and consequent morbidity and mortality. Keywords12,13 On base of BMI data, men have more BMI when compared with women, generally. However, more men are overweight than women, but in almost more women than men are obese through the world.14 Same to BMI, Waist Circumference (WC) is a useful predictor, commonly, for Coronary Heart Disease (CHD) risks and undesirable profile of blood fats (Table 1). It is reported that there is a clear relation between the accumulation intra-abdominal fat and WC and increased hazards.5 On this base, WHO suggested WC measures for predict of hypertension and lipid disorders, particularly low high density lipoprotein...
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