Journal of Sport Biosciences
Year:2010 | Volume:- | Issue:5|Papers Count:11

The purpose of this study was to compare the effects of active and passive recovery on immune system indexes after a graded exhaustive exercise in male college athletes. For this purpose, 20 college athletes of physical fitness training were selected by Cooper test and their BMI and then they were divided into two groups randomly: Group 1 (active recovery) and group 2 (passive recovery). Each subject completed Bruce protocol until exhaustion and then group 1 performed a 15-minute active recovery with 65% to 75% maximal heart rate on a treadmill and group 2 had a 15-minute rest for recovery in a supine position. Then, both groups had their recovery in a sitting position for additional 15 minutes. The blood samples were collected before, immediately, 15 and 30 minutes after the exhaustive exercise. The variance analysis of repeated measures showed a significant increase in leukocytes, lymphocytes, monocytes, neutrophils, CD4, CD8, and a decrease in CD4 to CD8 ratio in both groups immediately after the cessation of the exercise (P<0.05).Both recoveries significantly decreased leukocytes, lymphocytes, monocytes, CD4, and CD8 but there were no significant differences between the two groups during recovery periods. All indexes were approximately located near the baseline at the end of the two recoveries, except for the monocytes in group 1.

Plasma levels of adhesion molecule and lipid profile have emerged as an important indicator of risk for cardiovascular diseases. The aim of the study was to evaluate the effects of regular physical activity on cardiovascular markers (ICAM- 1, VCAM-1) in sedentary obese men. Eighteen young sedentary obeses males (mean and SD of age, weight and BMI were respectively as follows: 20.1±0.97 years, 93.3±10.70 kg and 30.7±3.4 cm/m2) were voluntary assigned and randomly divided into two groups: experimental (N=9) and Control (N=9)]. The training program includes 16 weeks of running aerobic activity, 3 sessions a week, each session 45-60 minutes at 60%-65% reserve heart rate. Fasting blood sample were analyzed for ICAM-1, VCAM-1 levels and lipid profile before and at the end of the study. Data analysis with pair t test showed that ICAM-1 level decrease in the experimental groups (P=0.01, 7%) and VCAM-1 decreased as well (P>0.05, 10%). The levels of TC (P=0.04, 19%) LDL-C (P=0.04, 30%) and risk factors decrease significantly. HDL-C increase in the experimental group (7.5%, P>0.05). The WHR (P<0.05, 2.1%), weight and BMI in experimental group significantly decrease (P<0.05). A moderate relationship was observed in WHR with ICAM-1 (R=0.40) and VCAM-1 (R=0.32). Also the moderate correlation was observed between changes of BF% and LDL-C with ICAM-1 (R=0.47, P>0.05). The results showed that changes in cholesterol, LDL-C and VCAM-1 will be possible if exercise is performed with 60%-65% reserved heart rate. On the other hand, although changes of BF%, weight and central obesity in subjects happened parallel with a decrease in VCAM-1 levels, there is not significant correlation among them in young men.

The purpose of this study was to investigate the effect of short term creatine monohydrate supplementation on baseline homocysteine concentrations and following an exhaustive exercise in active men. Twelve male students who were members of soccer team of Mazandaran University (age: 21.83±2.20 years, BMI: 13.53±58 kg/m2, Homocysteine: 13.53±58 mmol/lit) volunteered to participate in this study. They were randomly divided into creatine monohydrate (n=6) and placebo (n=6) groups. After 12 hours of fasting, blood samples were gathered before and immediately after the exhaustive exercise. Each subject of the experimental group received creatine monohydrate (0.3 g/kg) for 5 days. After these 5 days of supplementation, blood samples were gathered before and immediately after the exhaustive exercise. Dependent and independent t-tests were used as the statistical method (P£0.05). Results showed that these 5 days of creatine monohydrate supplementation significantly decreased baseline plasma homocysteine (P=0.017), and following the exhaustive exercise (P=0.013). It appears that creatine monohydrate supplementation prevents the probable negative effects of homocysteine on health with a reduction in the baseline levels and following an exhaustive exercise.

The purpose of this study was to determine the effects of official soccer competition on saliva cortisol, testosterone and immunoglobulin A in male players. For this purpose, 14 fixed players (age: 28.24±4.3 years) were equally selected from two opponent teams in 2009 Elimination Cup. Saliva samples at the rest and immediately after the first half time, before and after the second half time were collected and concentration of cortisol and testosterone through radioimmunoassay procedure and concentration of immunoglobulin through a nephelometry procedure were measured. Data were analyzed using analysis of variance of repeated measures and paired t test at P£0.05. Results of this study showed that the official soccer competition significantly influenced saliva cortisol, testosterone, and immunoglobulin A in male players (P<0.001). This finding suggests that official soccer competition may results in decreased concentrations of immunoglobulin A in male players and expose them to the upper respiratory tract infection.

The purpose of this study was to determine TV and computer games in underweight and obese boys and their relationship with physical activity, fitness and body composition.482 male students (9 to 15 years old) participated in this study. They were selected from state (n=286) and private (n=196) schools. Subjects were sampled in two stages; at first, cluster sampling was randomly performed and some schools were selected by their geographical location and then some students from different classes were randomly selected. Anthropometric measurements including height, weight and body mass were assessed (149±13.1 cm, 45.32±14.05 kg, 19.85±4.04 kg/m2 respectively). Data of TV and computer games and physical activity level were collected via time diary questionnaire. To determine weight classes (obese, overweight, normal weight, underweight), the Cut off-BMI was used. Fitness level was assessed via AAHPERD test. Statistical analysis was applied using the Kendall's correlation coefficient, Kruskal-Wallis and U-Mann Whitney tests. Results indicated a significant difference in the level of TV and computer games between underweight and obese boys (P<0.05): obese boys spent more time to watch TV and play computer games when compared to underweight boys. Also, the results indicated a significant relationship between TV and computer games with physical activity, lean body mass, percent of body fat and BMI (P<0.05). But there was not a significant relationship between TV and computer games with fitness (P≥0.05). Therefore, we can conclude that high level of TV watching and playing computer games results in obese and overweight children and limiting TV and computer games may be useful for preventing children from gaining weight.

The aim of the present research was to study the effects of regular training and exhaustive exercise on t-PA/PAI-1 complex in the blood of forty eight rats. They were divided randomly into control and experimental groups and the subgroups included the primary acute, secondary acute and 8-wk regularly trained (each group 8 rats). Endurance training programs (five days a week, speed 15-22 m/min for 25-64 minutes) and exhaustive exercise (5 minutes of running with speed 20m/min, 10 minutes of running with speed 25m/min, and running with speed 30 m/min to exhaustion). Blood samples were gathered following 12 hours of overnight fasting. The tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI-1), t-PA/PAI-1 complex were measured by Elisa methods respectively. Data was analyzed by two-way ANOVA with repeated measures and independent t-student tests at P£0.05. The results showed that exhaustive exercise impaired fibrinolysis process and interestingly this destruction due exhaustive exercise after 8 weeks of activity was worse in training group than control group. Furthermore, significant increase in t-PA (P=0.04) and t-PA/PAI-1 complex (P=0.000) values and insignificant PAI-1 (P=0.857) concentration was observed in the training group when compared with control group. In other words, regular training significantly increased t-PA (P=0.001) and insignificantly decreased PAI-1 (P=0.104) in training group when compared with the control group. These findings suggest that regular training does not highly influence destruction of hemostasis system due to exhaustive exercise. But regular training improves fibrinolysis process.

The aim of this study was to compare the effects of substitution of upper and lower body exercises during rest intervals on the quantity of upper body performance and lactate with 75% 1RM (Repetition maximum). For this purpose, 15 trained bodybuilders (age 20.9±1.9 years, weight 74.8±5.2 kg and aerobic power 35.48±8.6 ml/kg/min) took part in this study voluntarily. All subjects performed four testing sessions of bench press with 48 hours of recovery between sessions. In the first session, 1RM was measured. During the second to fourth session, subjects performed four sets per session with 75% 1RM up to voluntary exhaustion. In each session, subjects completed one of the following models: bench press movement with inactive rest (P1), bench press movement with leg extension and inactive rest (p2), and bench press movement with seated rowing and inactive rest (p3) randomly. For statistical analysis of data, two-way repeated measures ANOVA and LSD post hoc test were used. The results showed that all three exercise models reduced the repetitions in consecutive sets, and there were significant differences between consecutive sets (P=0.001). Also, sustainability of repetitions in P1 exercise model was significantly higher than P3 exercise model (P=0.001), and P2 exercise model than P3 exercise model (P=0.02). The present findings indicated a significant difference between lactate produced during P1 and P3 models (P=0.001), and P2 and P3 models (P=0.03). Therefore, as there was no significant difference between percentage of repetition and lactate production during exercise models of P1 and P2, it seems that combined upper and lower exercise reduces the time of exercises and maintains the repetitions at a higher level through decreasing lactate accumulation.

The aim of the present study was to investigate the effect of two programs of standard sets and circuit weight training with different intensities on response of excess post exercise oxygen consumption (EPOC) in young men. For this purpose, twelve healthy men (mean±SD: age, 21.92±1.1 years; height, 175.17±4.55cm; weight, 69.74±7.5kg) were voluntarily selected and participated in two stages of tests (resistance exercises at 50% and 75% of one repetition maximum). Excess post exercise oxygen consumption was measured before (baseline) and after resistance exercises for 90 minutes, each 30 minutes. Data were analyzed using two-way ANOVA with repeated measures, dependent t test and independent t test. The results showed that after both types of exercise, oxygen volume (VO2) significantly increased after 90 minutes when compared to the baseline (P=0.001). However, at the third 30 minutes after resistance exercise with 50% 1RM, VO2 did not significantly increase. The caloric consumption significantly increased for half an hour after resistance exercise with 50% and for an hour after resistance exercise with 75% 1RM. Respiratory exchange ratio (RER) significantly decreasedfollowing 90 minutes after both types of exercise when compared to the baseline (P=0.001). However, resistance exercise with 75% 1RM resulted in a greater increase in EPOC and caloric expenditure at three 30 minutes than resistance exercise with 50% 1RM. But there was no significant difference in RER between resistance exercises with 50% and 75% 1RM. In conclusion, these findings indicated that resistance exercise with standard sets and higher intensity resulted in greater EPOC during recovery until 90 minutes after exercise, so that if this type of training method is followed, it can be considered as a standard program to lose weight.