Journal of Sport and Exercise Physiology
Year:2015 | Volume:8 | Issue:1 |Papers Count:8

Introduction: Because sleep effects on most of the functions of daily life, it is an important aspect of life.Purpose: The aim of this study was to investigate the effect of 12 hours of sleep deprivation (30 hours wake) on health-related fitness factors including: muscular strength, muscular endurance, cardiovascular endurance, flexibility and body composition in active male college.Methodology: thirthy two active male college, with range of age 20 to 26 years, Height 1.64 to 1.90 meter, weight 58 to 85 kilograms and BMI 18.9 to 27.4kg/m2, were randomly divided into two groups of insomnia (n=16) and control (n=16). After the first day fitness tests administered to both groups, Subjects rested for three days and from 6: 00 am fourth day to 12: 00 am on the after day the experimental group spent a sleepless period. Then again on the fifth day both groups were performed of every fitness test. Average and range of differences were analyzed using independent t-test and software SPSS17.Results: After 12 hours of sleep deprivation, muscular endurance (P<0.003) subjects had significantly decrease, While had no significant change on muscular strength, cardiovascular endurance, flexibility and body fat of sleepless athletes (P>0.05).Conclusion: 12 hours of sleep deprivation cannot much cause reduction in physical performance. Therefore, athletes and non-athletes should get enough sleep at night to prevent performance decline in activities that require muscular endurance.

Introduction: Elucidating cell signaling mechanisms involved in muscle hypertrophy is one of the challenges of sport biologists.Purpose: The mammalian target of Rapamycin (mTOR) is the most important factor in this process that regulated through phosphorylated the ribosomal protein S6 kinase of 70 kDa (p70S6K) and increases protein synthesis in skeletal muscle. The purpose of this study was to determine the effect of resistance training (RT) on total (TmTOR) and phosphorylated (PmTOR) mTOR protein content and total (TP70) and phosphorylated p70s6k (PhP70) protein content, as markers of hypertrophy regulation in flexor hallucis longus (FHL) in normal male rats undergoing RT. For this purpose, 12 male Sprague Dawley rats were randomly divided into control (6=n) and RT (6=n). The RT consisted of climbing a ladder carrying a load suspended from the tail for 8 weeks (5 session week). The load of training was progressively changed 30-200 % of subject's bodyweight. To investigate muscle samples, 48 hour after the last training session, FHL muscle was removed while animals were anestheitized. TmTOR, PmTOR, TP70PC and PhP70PC was measured by ELISA in muscle extract. One-way ANNOVA was used.Results: The results showed RT muscle had a significantly greater Pour and p70s6k (P=0.001) (P=0.04).but no significant difference in TmTOR and p70s6k (p=0.421) (p=0.94). Totally, these Conclusion: findings, demonstrate that RT causes hypertrophy with increased phosphorylation of mTOR and p70s6k fitted.

Introduction: Obesity is associated with many cardiovascular and metabolic diseases including insulin resistance. NGAL, as an adipockin secreted from fat tissues, has been recently indicated to be particularly related to obesity and insulin resistance. The purpose of this study was to examine the effect of an interval period of aerobic training on plasma levels of lipocalin-2, insulin, glucose and Homeostatic model assessment ((HOMA-IR) in obese women.Methodology: 18 sedentary obese women (BMI³30 Kg/m2) were randomly assigned into experimental and control groups and were asked to participate in interval aerobic training sessions with moderate intensity (60-75% of Reserve Heart Rate) (HRR) for 8 weeks (three days a week, 60 min per session). Plasma levels of lipocalin2, insulin, glucose and (HOMA-IR) Two blood samples were taken (after 12 hours fasting) before and 48 hours after final trianing session. Data were analyzed by using (ANCOVA), paired dependent t-test and Pearson correlation at the (P<0.05).Results: The result while 8 weeks of interval aerobic training with moderate intensity showed a significant change in insulin (P<0.05) and HOMA-IR (P<0.05), changes in plasma levels NGAL (P>0.05) and glucose (P>0.05) tuned out insignificant. Moreover, there was no significant relationship between the level of lipocalin 2 and values of glucose, insulin and HOMA-IR (P>0.05).Conclusion: the results of this study indicated that this kind of training improved insulin resistance; however, a definite statement about the changes in NGAL levels warrants further research.

Aims: The aim of this study was to investigate the effects of 10 week high intensity interval training on serum levels of irisin and insulin resistance index (HOMA-IR) in male rats.Methodology: sixteen male wistar rats were randomly divided in two control (n=8) and training (n=8) groups. Training group performed high intensity interval training (1 min/sprint, 6~10 sets/day and 5~6 days/week) for 10 weeks. Blood samples were collected 48 hours after last training session and serum levels of irisin, insulin and glucose were measured using ELISA and glucose oxidase method. Statistical analysis was done by ANOVA and Pearson correlation and (P<0.05) was considered significant.Results: serum levels of irisin (P=0.004) significantly increased following 10 week high intensity interval training. In addition serum levels of fasting glucose and HOMA-IR were decreased in the trained group but were not significant (P>0.05). Also serum levels of insulin in the trained group were more than control group but were not significant (P>0.05). Hence there were not significant correlations between irisin levels and insulin and HOMA-IR (P>0.05) but correlations between irisin and glucose were not significant (P=0.029).Conclusion: high intensity interval training increases irisin levels and improves insulin resistance index in male rats

Aim: The purpose of this study was to evaluate time to exhaustion analysis in soccer players based on their heart rate changes slope and blood lactate changes in a gradually increasing test.Methodology: the participants in this research project were 20 soccer players of the first division club with an average age of 19±1.58 yr, 179 ±6.26 height cm and 66±8.64 kg weight. Time to exhaustion and blood lactate changes were measured during the incremental ramp test. Likewise during the steps of heating, running ramp protocol and cooling the Subjects Heart rate First Division clubs in the country were the participants in this research project. Laboratory tests increased time to exhaustion, lactate changes during the ramp incremental test were measured. Heart rate at all stages of heating, and cooling ramp protocol run by a Polar heart rate meter and recorded Measurement Was and heart rate threshold and slope changes using Mathematical software and Dmax method for individual subjects were calculated. Running The Kolmogorov Smirnov test and ensuring the availability of the application of parametric statistical test, Pearson correlation coefficients were calculated between the variables. All statistical procedures using SPSS software and survey data at a significance level of 0.05 was used.Results: based on results of research the correlation heart rate changes slop were r=- 0.76 with blood lactate and r=- 0.67 with the time to exhaustion.Conclusions: The Research findings showed that, Because of using accurate mathematical methods in Calculating and plotting the Heart rate changes slope, utilizing such heart rate changes slope to measure the fitness of athletes by coaches and athletes is recommended.

Introduction: Many studies indicated that sleep deprivation has several different effects on athletic performance. However, there are controversies in findings and little attention has been on the interaction of sleep deprivation with circadian rhythm.Purpose: The aim of this study was to investigate the effect of 4 hours of sleep deprivation on indices of skill related physical fitness during morning and evening.Methodology: Twenty three female collegiate athletic students with at least 2 years’ experience of regular participation in sport activities (age: 21.47±0.73yr, height: 160.4±4.82 cm, weight: 56.25±1.07 kg) participated in this study voluntarily. Study variables were measured during 4 testing sessions with one week interval. Measurements were performed after 8 hours sleep deprivation during morning (0: 700-0: 800) and evening (18: 00-19: 00). Measured study variables and tests included neuromuscular coordination (stick test), reaction time (nelson test), balance (static balance test) and agility (Illinois test).Results: Four hours of sleep deprivation induced negative effects on reaction time and balance during morning (p=0.01 and 0.035 respectively). But did not cause significant effect on agility during morning and evening (p>0.05).Conclusions: It was concluded that short-term sleep deprivation adversely affects reaction time and balance in the morning.

Aim: Inactivity can adversely affect on health of lean subjects. A few findings are available about novel insulin resistance indices. The purpose of this study was to investigate effect of endurance training on novel insulin resistance indices and some of cardio metabolic risk factors in inactive lean men.Methodology: In a semi-experimental study, twenty inactive lean men were randomly placed at two groups: endurance training (n=10, 21.2±2.2 yr) and control (n=10, 21.4±2.7 yr). General characteristics of subjects, Adiponectin-Resistin (AR), homeostasis model assessment-Adiponectin (HOMA-AD) and insulin resistance index (IRAR), blood pressure, and lipid profile were assessed before and after training. Endurance training consisted of twelve weeks pedaling on ergometer cycle (3 sessions per week, intensity 60-70% of reserved heart rate, duration of each session 20-40 min). Data analyzed by paired- and independent-t tests. Statistical significance was accepted at P<0.05.Results: After the training period, HOMA-AD (P=0.043), IRAR (P=0.029), systolic blood pressure (P=0.022), diastolic blood pressure (P=0.038), and serum triglyceride (P=0.019) were reduced, while serum Resistin, AR, total cholesterol, high density lipoprotein, and low density lipoprotein did not change significantly (P>0.05).Conclusion: Decreases of HOMA-AD and IRAR indices, systolic blood pressure, diastolic blood pressure, and serum triglyceride after twelve weeks endurance training in inactive lean men indicate that endurance training can be useful for metabolic and cardiovascular health of inactive lean men via improving insulin resistance, blood pressure, and circulating levels of triglyceride.

Aim: Anti oxidative enzymes and heat shock protein72 (HSP72) are two important internal body protective factors. The purpose of present study was to determine the effects of 1 and 12 sessions of high intensity interval training in warm and normal environment on serum levels of Glutathione peroxidase and HSP72 in active men (at least 8 hours per week).Methodology: Twenty four physical education students of Kharazmi university were divided into three equal and homogenous groups include: exercise in warm environment(temperature 40 ± 1, humidity 35 ± 5), exercise in normal environment (temperature 24, humidity 35±5) and control group. Training protocol included running on treadmill with 85% vVO2max intensity in 5 sets per 150 second. Training sets separated from each others by running with 50% vVO2max intensity as a recovery time (150 second). Blood samples were taken before and after first activity session and 24 hours after last training session and Glutathione peroxidase (GPX) and HSP72 levels measured via ELISA method.Data was analyzed using the independent and dependent t tests and one way ANOVA at significance level of p<0.05.Results: Serum levels of GPX and HSP72 increased significantly after 1 and 12 sessions of high intensity interval training compared to pre-test in both of warm and normal environment groups. However any between group significant differences was not observed in these two groups. Furthermore, after 12 session of practice the serum level of GPX in both warm and normal environment training groups increased significantly in comparison with control group, but the serum level of HSP72 was not significant in two training groups when compared with control group.Conclusion: In general result of present study showed that 1 session and 1 high intensity interval training period is stimulator of GPX and HSP72 and arising the environmental temperature has no effect on response and adaptation values of mentioned factors.