Journal of Sport and Exercise Physiology
Year:2020 | Volume:13 | Issue:1|Papers Count:10

A novel virus that expanded globally from China known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causing Corona Virus Disease 2019 (COVID-19). Based on the pandemic and fast spreading characteristics of corona virus (COVID-19), it causes concerns for elderly individuals and those with chronic diseases. To lower the chances of spreading the coronavirus, and preventing the social and economic burden, most of the credible medical centers and organizations have recommended social distancing and isolations. Disclosure of gyms and sport centers and isolation has resulted in inactivity in different individuals. The corona virus disease has led to challenges for keeping the active lifestyle and it can induce some diseases due to inactivity such as obesity metabolic disorders (e. g., diabetes), cardiovascular diseases, and other diseases that can increase hospital referral. Since this is a novel disease and although the effects of regular exercise on it has not been investigated yet, exercise and active lifestyle through increasing energy expenditure, body metabolism, and improving physical and psychological fitness can result in increasing health, reducing virus infection and in the case of having the corona disease it helps a quicker recovery. Since, corona disease influences on the immune and cardiorespiratory system and the person’ s physical fitness can be effective in tolerating the disease side effects, this article expands on the effects of regular exercise on immune system, viral infections (inflammation), cardiorespiratory system and physical fitness and at the end presents exercise guidelines for different populations.

Purpose: Previous studies in the case of fish oil showed its effectiveness on reducing inflammation and improving performance, but its effects on peripheral fatigue and related mediators are not well understood. Methods: 20 healthy men students (age: 26. 90± 2. 64 yrs, weight: 78. 33± 10. 42 kg, height: 175. 80± 4. 89 cm, body fat percent: 18. 40± 5. 46) were selected and randomly assigned into corn oil and fish oil groups and consumed daily doses of 6 gr for 4-weeks. Before and after supplementation, participants performed Bruce exhausting protocol and blood samples were taken before, immediately after and after 20-min recovery. Results: Our results showed significant decrease in baseline values of TNF-α and significant increase in baseline values of NO (P<0. 05) after supplementation. In addition, three were significant differences between groups after supplementation in changes of TNF-α after recovery (F=7. 38, P=0. 015) and changes of NO after exercise (F=5. 64, P=0. 034) and recovery (F=8. 83, P=0. 011). However, no changes observed in the case of ROS. Conclusion: These results showed that fish oil supplementation could reduce baseline inflammation and thus, increase baseline NO that can improve anti-oxidant capacity. However, TNF-α response to recovery increased that seems to be highly affected by increase in post-supplementation baseline. In addition, NO responses to exercise decreased that is may be because of the lower physiological stress of activity.

Purpose: Although physical activity is one of the medical aid strategies to reduce arterial stiffness in diabetic patients, the mechanism remains unclear. The purpose of this study was to determine the effect of aerobic exercise on Klotho-fibroblast growth factor-23 (FGF23) axis and arterial calcification in type 2 diabetic postmenopausal women. Methods: Twenty-four type 2 diabetic postmenopausal women who were registered at the diabetes association of Shahrood, were randomly assigned into two groups including exercise (n=12, 51± 6 yrs., 31. 9± 5 kg/m2) and control (n=12, 52± 5 yrs., 29. 23. 8 kg/m2). The aerobic training consisted of 45 to 60 minutes running with 45 to 70 percent of heart rate reserve, three sessions per week for 8 weeks. Before and after the experimental period, blood fasting samples were taken and the ELISA method was used to analyzed Klotho-FGF23. Arterial stiffness analysis was also performed using VaSera-VS-2000. The data were analyzed using the statistical tests of Paired and Independent t-test (P<0. 05). Results: No significant changes in phosphor, FGF23, phosphor × calcium, diastolic blood pressure and VO2max were found in this study (P>0. 05). But, calcium levels in exercise group decreased significantly following the experimental period (P<0. 05). Moreover, systolic blood pressure, Klotho-FGF23 and arterial stiffness significantly decreased and klotho significantly increased in exercise group (P<0. 05). Conclusion: Aerobic training can decrease the arterial stiffness by modifying the underlying causes of SBP, Klotho and Klotho-FGF23 in postmenopausal women with diabetes. However, due to the few studies in this regard, these findings need to be validated in the future studies.

Purpose: The present study aimed to determine the effect of a strength training course with different rest intervals on some physiological and biochemical characteristics in inactive healthy men. Methods: 30 non-athlete male (18. 97± 2. 30 years old, 18. 78± 4. 89 cm, weight 68. 94± 1. 35 kg) were randomly divided into three groups: strength training with decreasing rest (from 3 minutes to 30 seconds), strength training with increasing rest (30 seconds to 3 minutes) and strength training with constant rest (3 minutes; control group). Training groups (with a special periodization in terms of load, severity and distance between sets) had 9 weeks and 3 sessions a week. Strength training program wad 5 to 8 sets with 3 to 15 repetitions and loads of 60 to 90% of a maximum repetition. The only difference between the groups was the gap spacing applied between the sets. Also, two sessions of plyometric supplement training (60% HR intensity) were performed during the week. Blood samples were taken at fasting time before and after 48 hours passed from training period and analyzed by radio-immunoassay method in the laboratory. Data were analyzed using covariance test. Results: Maximal strength, muscle endurance and testosterone concentration increased significantly in all three groups; and the difference between the groups was significant, but the percentage change in all tests in the first and second groups was higher than in the third group, but not significant. Also, after the training session, the concentration of growth hormones, fat percentage, free fat mass and body fat mass index increased and decreased significantly, respectively; Of course, the difference between the groups was not significant. Conclusion: Resistance training with rest intervals of increasing and decreasing in comparison with rest intervals constant, due more to increase maximal strength, muscular endurance and some biochemical and hormonal factors.

Purpose: Sodium bicarbonate with buffering effect is one of the additives and effective supplement to reduce fatigue. Therefore, the main objective of the present study is to investigate the acute effect of sodium bicarbonate supplementation on anaerobic performance in elite and non-elite male cyclists. Methods: In a single-blind crossover study 12 semi endurance elite cyclists (with 3 year national and international competitions experience) and 16 non-elite cyclists (no history of official competition) in the range of 17– 29 years old selected purposefully and were placed in two group. Both group within one week, 60 minutes before the test, consumed 100 mg placebo (NaCl) or 300 mg sodium bicarbonate per kg of body weight of dissolved in 200 ml of water. The Wingate anaerobic test, measure participants peak power, average power, power drop and recovery heart rate indexes and the results were analyzed by using analysis variance (2×2) (P <0. 05). Results: Dependent variables response to sodium bicarbonate supplementation had no significant difference between two groups (P>0. 05). However, in both group the acute supplementation of sodium bicarbonate result in a significant increase in peak power (P<0. 001) and average power (P=0. 001) and result in a significant decrease in power drop (P<0. 001) and fifth minute recovery heart rate (P<0. 001). Conclusion: According to improvement of anaerobic capacity of elite and non-elite male cyclists following acute supplementation of sodium bicarbonate, its effectiveness is possible regardless fitness level or muscle buffering capacity.

Purpose: Finding genetic structures effecting on athletic performance is an important step in developing methods related to talent identification and as well as personalizing athletic training programs. The previous investigations revealed the insulin-like growth factor (IGF2) is associated with body mass index, fat-free mass, hand grip strength and leg strength. The purpose of this study was to evaluate the frequency of IGF2 rs680 polymorphism in Iranian male judo athletes. Methods: The athlete group includes 40 elite judo athletes who had medals in Asian and World championship. The control group comprised of 120 health non-athletes men. DNA was extracted from the peripheral blood using a non-enzymatic method and genotyping was conducted by PCR method for identifying the IGF2 rs680 polymorphism. The distribution frequency of this polymorphism was determined by chi-square analysis. Results: There were no significant differences in genotype frequency between judo athletes (G/G=37. 5%, G/A=42. 5%, A/A=20%) and control group (G/G=30. 8%, G/A=48. 3%, A/A=20. 8%) (in all genotypes P 0. 5) and also in allele frequency between judo athletes (G=58. 8%, A=41. 2%) and control group (G=55%, A=45%)(P=0. 55). Conclusion: Regarding that the exercise is polygenic and many genes play a role, and given that judo sport is affected by various factors and is not completely dependent on a factor such as strength or endurance, it is likely that the polymorphism IGF2 rs680 is not a significant genetic marker in judo sport in the Iranian male population.

Purpose: Muscle strength is needed to perform many movements and skills in football such as speed decreasing, shooting, dribbling, rotating, and jumping. Several studies shown that lower limb muscle strength can increase the quality of exercise skills. But, few studies have compared the strength of players at different levels. Therefore, the present study intends to investigate the strength of the isokinetic and isometric knee muscles of the elite, sub-elite and amateur football players of Iran. Methods: The isokinetic strength of the knee muscles in 102 soccer players including 29 players of the national under-23 football team of Iran (elite), 29 players of 1st division of under-23 football team of Iran (sub-elite) and 44 players of 2nd division of under-23 football team of Tehran province (amateur) was measured for angular momentum of 60 and 180 degrees per second by the isokinetic Biodex. The isometric strength of flexor and extensor muscles of knee were measured at an angle of 60 degree. Results: The results of the ANOVA test showed that elite player had superior strength of flexor and extensor knee muscles in both momentum angles of 60 and 180 degrees per second and flexor/ extensor isokinetic strength ratio at 180 degrees per second speed than sub-elite and amateur players significantly. However, there was no significant difference in the ratio of flexor/ extensor isokinetic strength ratio at 60 degrees per second. Conclusions: Considering the results of the present study, it can be concluded that competition level affect the isokinetic and isometric strength of the knee muscles of young football players of Iran.

Purpose: Hydrogen sulfide has an important role in the body's physiological functions. The aim of the present study was to survey on the effects of 4-week aerobic training on CBS, SAM and H2S levels in hippocampus of Wistar male rats. Methods: 14 male Wistar rats (12 weeks old and weight 195± 20 g) were randomly divided into two groups including: control and aerobic training. Training group trained 5 days a week for 4 weeks (15 minutes at 10 m/min). CBS and SAM mRNA expression in hippocampus was measured by Real time-PCR techniqiue and the ELISA method was used to measure H2S. For data analysis, MANOVA and Eta and Omega squared tests were used to determine the effect size at 95% confidence level (P<0. 05). Results: Findings revealed that the 4-week of special aerobic training increased significantly the CBS, SAM and H2S levels in hippocampus of training rats compared to the control rats (ES=68. 15, P=0. 002; ES=84. 85, P=0. 001; ES=77. 32, P=0. 001). Conclusion: According to the results, it seems that the special aerobic training can play an important role in physiological and pathophysiological functions through positive regulation of hydrogen sulfide via CBS and SAM enzymes and as a non-pharmacologically beneficial therapeutic treatment for dementia patients.

Purpose: Myocardial infarction (MI) is the irreversible cell death by ischemia in parts of myocardium. The molecular process of increased capillary density in response to activity and its appropriate intensity is not clear yet. Therefore, this research aimed to evaluate the effect of 6-week high intensity interval training on expressions of MMP-9, eNOS and the ratio of VEGF to COL-18 genes on rats with myocardial infarction. Methods: 12 Wistar male rats of 10 weeks old and mean weight 250-300gr were allocated to two groups of experimental (60 minutes of interval treadmill running for 4 minutes with the intensity of 85-90 percent of VO2max and 2 minutes of active rest at 50-60 percent of VO2max for 4 days a week for 6 weeks) and control group (without any training). Real-time PCR was used to assess the expression of MMP-9, eNOS VEGF and COL-18 genes after inducing MI, and shortening fractional and ejection fraction were investigated as echocardiographic indices. Data were analyzed in SPSS18 using independent t test (P≤ 0. 05). Results: The findings showed that the amount of MMP-9 in HIIT (3. 541 mg/ml) is significantly much more than the control group (1. 002 mg/ml) (P=0. 012) and the amount of eNOS in HIIT group (4. 23 mg/ml) was also significantly much more than control group (3. 68 mg/ml) (P=0. 014) but there was no significant increase in the VEGF/COL-18 ratio in the HIIT group (1. 856 mg/ml) as compared with the control group (1. 245 mg/ml) (P=0. 263). Conclusion: In general, 6 weeks of high intensity interval training can effectively increase MMP-9, eNOS and the ratio of VEGF to COL-18 genes and improve myocardial function in male Wistar rats after MI.

Purpose: Sirtuins-3 (SIRT3) is a mitochondrial deacetylase and through acetylation of Oxoguanine Glycosylase 1 (OGG1) protein caused repair mitochondrial DNA damage and prevents cell apoptosis. The purpose of this study was to evaluate the effect of vigorous continuous and interval exercise training along with resveratrol on SIRT3 and OGG1 proteins in the liver tissue of male Wistar rats. Methods: In this research, 48 male Albino Wistar rats were divided into six equal of eight groups including sedentary control, supplement, interval exercise, interval exercise + supplement, continuous training and continuous training +supplement. Continuous and interval training performed for 6 weeks, 6 days per week at speed of 27 and 54 m/min respectively on a rat treadmill. Resveratrol users received daily 50 mg/kg of body weight supplements as gavage. After intervention, the animals were anesthetized and their liver samples were analyzed using one-way ANOVA and Tukey's post hoc tests. Results: After 6 weeks, OGG1 level was significantly increased in continuous exercise (P=0. 0001) and continuous training + supplement (P=0. 0001) groups relative to the control group. Also, liver tissue SIRT3 levels in supplementation group (P=0. 01), interval training group (P=0. 04), interval training + supplement group (P=0. 04), continuous exercise group (P=0. 001), and continuous training + supplement group (P=0. 001) increased than control group after six weeks. Conclusion: Compare to the interval training, performing of continuous training along with resveratrol consumption can induce more improvement in cell survival and life-span factors such as SIRT3 and OGG1.