فصلنامه علوم زیستی ورزشی
پیاپی 19 (زمستان 1392)

High-intensity interval training (HIT) is an efficient means of improving performance in a short period of time. The effects of HIT program on performance، physiological and resting levels of growth hormone (GH)، IGF-1،IGFBP-3 and Cortisol in elite athletes are not well known. So، the present study was conducted to show the effect of four weeks HIT on some functional and hormonal variables. For this purpose، fourteen Iranian volunteer players in nationalB basketball team (Mean±SD، age=23. 0±3. 24، weigth=63. 6±8. 50، BMI=21. 8±3. 15) were selected and were randomly divided into two groups of experimental (EXP: n=7) and control (CON: n=7). Before and after training، the subjects performed (a) a graded exercise test، and (b) a Wingate test for determining Peak Power Output (PPO) and Mean Power Output (MPO). Both groups followed the same basketball training program for four weeks. Additionally، the EXP group performed a Running-based Anaerobic Sprint Test (RAST) (six 35-m runs at maximum pace with a 10-second recovery between each run) as a HIT protocol for four weeks، two sessions per week. Statistical analysis was done by analysis of covariance (ANCOVA)، using SPSS 16، and P<0. 05 was considered significant. According to the results of ANCOVA test، EXP group showed significant improvement in VO2 max (P=0. 001)، vLT (P=0. 011) and vVO2 max (P=0. 001). The training program led to significant increases in PPO (P=0. 03) and MPO (P=0. 02). The current findings suggest that HIT program with short recovery can increase both aerobic and anaerobic performances.

The purpose of this research was to determine the effects of intermittent and continuous training on inflammatory factors of CRP and fibrinogen of young obese females. For this purpose، 36 obese sedentary subjects (body mass index>30) were randomly selected and randomly assigned to 3 groups of 12 subjects: intermittent training، continuous training and control (mean and SD of height، weight، age 163. 2±5. 8 cm، 86. 8±11. 8 kg، 20. 7±1. 3 years; 160. 2±6. 4 cm، 83. 8±9. 5 kg، 22. 1±2. 2 years; 166. 2±7. 1 cm، 86. 6±10. 5 kg، 22±2. 4 years، respectively). The intermittent group participated in an 800-meter (4 x 200m run = 800m) exercise with 80%-90% of maximal reserved heart rate and 1/3 rest interval. A distance of 400 meters (2 x 200m) was added to the primary distance every week. The continuous group ran this distance (800 m) with 60%-70% of maximal reserved heart rate with 400 meters added to the primary distance weekly. The control group received no intervention. Before and after the protocol، fibrinogen and CRP were recorded and measured. One-way analysis of variance، LSD post hoc test and paired t tests were used to determine the effects of both types of exercises (α=0. 05). The intr-group results showed a significant decrease in fibrinogen in the continuous group (P=0. 005). The intera-group results revealed a significant change of CRP between the intermittent and continuous groups (P=0. 04) and also between the intermittent and the control groups (P=0. 001). In addition، there was a significant change of in fibrinogen between the intermittent and control groups (P=0. 006). It seems that both types of exercise had positive effects on CRP and fibrinogen levels.

High-intensity interval training (HIT) is an efficient means of improving performance in a short period of time. The effects of HIT program on performance، physiological and resting levels of growth hormone (GH)، IGF-1،IGFBP-3 and Cortisol in elite athletes are not well known. So، the present study was conducted to show the effect of four weeks HIT on some functional and hormonal variables. For this purpose، fourteen Iranian volunteer players in nationalB basketball team (Mean±SD، age=23. 0±3. 24، weigth=63. 6±8. 50، BMI=21. 8±3. 15) were selected and were randomly divided into two groups of experimental (EXP: n=7) and control (CON: n=7). Before and after training، the subjects performed (a) a graded exercise test، and (b) a Wingate test for determining Peak Power Output (PPO) and Mean Power Output (MPO). Both groups followed the same basketball training program for four weeks. Additionally، the EXP group performed a Running-based Anaerobic Sprint Test (RAST) (six 35-m runs at maximum pace with a 10-second recovery between each run) as a HIT protocol for four weeks، two sessions per week. Statistical analysis was done by analysis of covariance (ANCOVA)، using SPSS 16، and P<0. 05 was considered significant. According to the results of ANCOVA test، EXP group showed significant improvement in VO2 max (P=0. 001)، vLT (P=0. 011) and vVO2 max (P=0. 001). The training program led to significant increases in PPO (P=0. 03) and MPO (P=0. 02). The current findings suggest that HIT program with short recovery can increase both aerobic and anaerobic performances.

The purpose of this study was to study the effects of the 12-week resistance training program on some physical fitness and inflammatory markers factors in overweight men. In a semi-empirical trial، 25 young male (age= 20. 9 ± 1. 96 and height= 170. 34 ± 7. 39 cm) were purposefully selected and randomized in two groups of resistance training (n=15) and control (n=10) groups. The resistance training was performed with different intensities for a period of 12 weeks، three sessions a week. The resistance training consists of 6 stationary circular motions. 5 ml of venous blood was collected in fasting state before and 24 hours after the last training session to determine inflammatory markers. Independent and paired t test indicated that weight and BMI of subjects did not change significantly after 12 weeks of activity (P> 0. 05). But some physical fitness factors (1-RM leg press، VO2 peak، 1-RM bench press) increased، and some anthropometric factors (WH and percentage of body fat) decreased significantly، after 12 weeks (P <0. 05). The Exercise group showed significant reductions in insulin resistance، leptin level and tumor necrosis factor-alpha (TNF-α) (P <0. 05). Pearson correlation coefficient showed a significant relationship between TNF-α with BMI، W / H، percentage of body fat and insulin (P <0. 05). Based on the results of this study، it was found that 12 weeks of resistance training can improve some physical fitness and anthropometric factors and also inflammatory markers in sedentary overweight young men.

The aim of this study was to compare and validate the selected methods for estimating fat percentage. For this purpose، 30 inactive female students of Shahid Rajaei University (Age=20. 93±1. 91; Height=164. 73±4. 57cm; Weight=56. 65±8. 02 Kg) were selected voluntarily. They were randomly placed in one of the four different conditions (Digital، Harpenden، Plastic Calipers and Electrical Bioimpedance) on 4 separate days، in a crossover design for estimating fat percentage. Measurements were performed from 3 points (the triceps، iliac and femoral). The Results of repeated-measures ANOVA and Bonferroni post hoc test indicated that there were significant difference between harpenden and plastic calipers (P=0. 045) and between digital and plastic calipers (P=0. 003). The results of Pearson correlation coefficient indicated that There was a high correlation between digital and harpenden calipers as well (R=0. 898، P= 0. 000). Also the most Regression coefficient was allocated to digital caliper (β=0. 817) and electrical bioimpedance (β=0. 244) respectively and plastic caliper had the lowest place (β=0. 14). It is worth noting that the overlap of predictive variable of harpenden caliper was R2 = 0. 839 According to these results، it is recommended to use harpenden caliper for estimating fat percentage first. If there is no access to this caliper، you can use digital caliper and electrical bioimpedance respectively. Moreover، plastic caliper must be used with caution.

During repetitive tasks (such as running، walking and tapping)، music can effect on body movement rhythm. The purpose of this study is investigated the effect of music meter and tempo on cycling speed. Therefore، seventeen female physical education students with 22. 33±1. 22 age، 57. 23±10. 30 weight، 22. 09±3. 5 body mass index and 160. 55±4. 6 height were selected and examined during four sessions (each session contain of two trials). At first session، participants cycled without listening to music. At second، third، and fourth sessions and during cycling، participants listened to music pieces with 3. 4، 6. 8 and 7. 8 meters. For each meter، two pieces with two different speeds (60 and 100 bpm) were created and played for participants. With SPSS software and repeat measurement ANOVA، collected data were analyzed (at P=0. 01 significant level). Data analysis indicated that music meter doesn’t have significant effect on cycling speed (P=1. 00). The results indicated that there isn’t significant different between without music condition and 60 bpm speed meters (P=0. 517) but between without music condition and 100 bpm speed meters these different is significant (P= 0. 001). Therefore، it seems that music pieces with different meters (similar pitch and isochronous) had similar effects on cycling speed and music can synchronies and control cycling speed.

The purpose of present study was to examine the effects of caffeine and ephedrine supplement and their combination on maximal strength and mucular endurance in male bodybuilders. 12 male bodybuilders (mean age: 24. 41±4. 42 years، height: 174. 83±3. 61 cm and weight: 75. 67±8. 05 kg) were selected voluntarily. The study design was crossover، in which the subjects were placed in 7 different conditions of control (Con)، Ephedrine ((E)، 0. 8 mg/kg); caffeine ((C)، 6 mg/kg)، a combination of E + C (0. 8 mg/kg + 6mg/kg)، placebo 1، placebo 2 and placebo 3 (sarch powder as capsul) with a period of one week between each conditions. In each session، subjects performed a one repetition maximum (1RM) test for maximum strength and a 70 % repetition untill exhaustion test for muscular endurance in bench press and leg press. The data was analyzed using the Kolmogrov – Smirnov، repeated measrues ANOVA and Tukey post – hoc tests، at significance level of P<0. 05. The results showed that ephedrine and caffeine supplement caused significant increase in lower body strength (P<0. 05) and upper body endurance (P<0. 05). Also، combination of caffeine and ephedrine supplement caused significant increase in lower body strength and endurance (P<0. 05). In addition، caffeine and ephedrine supplement did not have any significant effect on upper body strength and lower body endurance. Caffeine and ephedrine combination had no significant effect on upper body strength and endurance. It can be concluded that male bodybuilders should consume ephedrine (0. 8 mg/kg) or caffeine (6 mg/kg) supplements for improving upper body endurance، and the combination of caffeine and ephedrine supplements for improving lower body endurance. All the three supplements can be used to improve lower body strength.

Exercise Training has been shown to decrease chronic low- grade systemic inflammation in high- fat diet induced obesity. However، the mechanisms mediating its beneficial effects are not fully understood. Therefore، the aim of this study was to investigate the effects of a 12- week endurance training on IL-6، IL-10 and nesfatin -1 in obese male rats. Sixteen male wistar rats (2 months old) were fed a high fat diet for 8 weeks، reaching an average weight of 319 ± 30g. The animals were randomly divided into control (n=8) and 12-week endurance training (T، n=8) groups. Training group was given exercise on motor- driven treadmill at 25 to 30 m/min (0% grade)، 60 min/day، 5 days/week for 12 weeks، and both groups were given “ad libitum”. The Elisa method was used for laboratory analysis of Nesfatin-1، IL-6 and IL-10. The results revealed that the average weight of rats in T group was significantly lower than that of the control group (P=0. 001). A significant decrease was also observed in IL-6 T group (P=0. 04). Nesfatin – 1 plasma level increased in T group (P=0. 001). Despite the fact that IL-10 was lower in T group، the difference was not significant. The results of present study showed that long- term endurance training led to an increase in the anti- inflammatory nesfatin -1، and nesfatin- 1 probably plays a role in energy balance، that is independent of the changes of IL-10 and IL-6 in plasma level.