negar kooroshfard

Despite the widespread use of cryotherapy in sports, there is no specific evidence of its impact on muscle activation, especially following fatigue-induced exercises. This study aimed to assess the impact of cryotherapy alone and after plyometric exercises on knee muscle activation during the drop jump task.

A total of 35 active female subjects (mean±SD age of 22.74±2.10 years, mean body mass index [BMI] of 20.02±2.55 kg/m2) participated in this quasi-experimental study with a pretest-Post-test design. There were three experimental groups (20-minute cryotherapy, plyometric, and plyometric-cryotherapy) and a control group. Electromyography (EMG) amplitudes of knee muscle activation (rectus femoris [RF], biceps femoris [BF], tibialis anterior [TA], medial gastrocnemius [MG]) were measured and compared in three phases of the drop-jump task (one feedforward preactivation and two feedback eccentric and concentric phases). Skin temperature was recorded before and after cooling intervention as well. For comparisons, repeated measure analysis of variance (ANOVA) was used at a significant level of 0.05.

The results showed that the skin temperature decreased significantly after cryotherapy and was maintained for 20 minutes. No significant changes were observed in the EMG of knee muscles in the feedforward and concentric phase of the drop jump task in any groups (P>0.05). However, RF activation decreased following cryotherapy immediately and after 20 minutes as an eccentric phase (P=0.01) and had a significant difference from the control group (P=0.01); besides, EMG activation decreased in cryotherapy, plyometric, and plyometric-cryotherapy groups immediately (P=0.01). However, no significant differences were seen between them and the control group (P>0.05).

According to the present results, cryotherapy alone and after fatigue-induced plyometric training had a minor effect on the knee muscle activation during a functional jumping movement, but the impact of these changes on knee biomechanics is insignificant; hence, further studies are essential for a better conclusion.

Since limited studies have examined the simultaneous use of creatine and sodium bicarbonate supplements in team sports, the aim of this study was to evaluate creatine and sodium bicarbonate supplementation on anaerobic performance, fatigue index and futsal special performance test (FSPT (in elite futsal players.

32 futsal players (age of 22.23± 0 0.23 years) were selected objectively and randomly divided into four creatine, sodium bicarbonate, combined and placebo groups. FSPT and RAST anaerobicity test was performed .intervention During 7 days of supplementation, the creatine group received 20 grams of creatine daily, the sodium-bicarbonate group 0.3 mg / kg, the combined group (20 grams of creatine and 0.3 mg / kg sodium bicarbonate) and the control group 20 grams of starch, in four servings.

showed that the peak of anaerobic power of creatine and combination groups was significantly higher than the placebo group. There was no significant difference in the fatigue index of the groups. There is a significant difference between the time of FSPT of each creatine and combination groups with the placebo and sodium bicarbonate groups and between the creatine and combination groups in the post-test

Creatine supplementation, unlike sodium bicarbonate, improves the anaerobic and functional parameters of futsal players. Also, the simultaneous use of creatine and sodium bicarbonate, by enhancing the synergistic effect, gives a more positive response to the anaerobic and functional indices of futsal players

This investigation aimed to compare the effect of neuromuscular, strength, and combined training on dynamic balance and sports performance, including power, sprint, and agility in female basketball players.

In this semi-experimental study, 42 female professional basketball players (age: 19-25 years) were assigned to three groups of Neuromuscular (NM), Strength (ST), and Combined training (CM), and one control group. The Multivariate Analysis of the Variance (MANOVA) was used to compare between-groups data. Dynamic balance and performance measurements (vertical jump, agility, and sprint) of athletes were assessed before and after six weeks of intervention by Star Excursion Balance Test (SEBT), Sargent vertical jump device, Shuttle Run device, and sprint 27-meter test. 

Results of the MANOVA showed all between-group differences for dynamic balance, sprint, and agility were only significant between the control group and NM, ST, and CM groups (P≤0.05). In addition, the CM group was significantly different compared to the NM and ST groups (P≤0.05). Balance and high jump within-group differences showed a significant increase in the NM, ST, and CM groups in the high jump variable (P≤0.05). For sprint and agility, within-group results showed a significant decrease in the NM, ST, and CM groups (P≤0.05). Besides, the larger effect size was seen in the combined group for all variables.

It seems that neuromuscular, strength, and combined training is similarly effective in improving the balance and functional performance of female basketball athletes and there is not a significant difference between them.

Osteopontin is a novel adipose tissue derived cytokine correlating with obesity and its related metabolic diseases such as insulin resistance and type II diabetes. The purpose of this study was to investigate effect of high intensity interval training (HIIT) on serum levels of Osteopontin, insulin and fasting glucose and insulin resistance index (HOMA-IR) in young sedentary overweight and obese women.

Twenty overweight and obese women randomly divided into two groups including experimental (mean age 32.5 ± 4.14 years, body mass index 33.18 ± 6.12 Kg/m2) and control (mean age 35.45 ± 2.33 years, body mass index 31.58 ± 1.65 Kg/m2). Subjects in experimental group participated in eight weeks of HIIT (one minute of running interval at intensity of 90 percent of maximal heart rate and one minutes of rest interval of running at intensity of 50-60 percent of maximal heart rate, 10 sets per session, 20 minutes per session, three times per week). Blood factors and body composition indices were assessed before and after training protocol. Statistical analysis was done by Covariance, paired t-test and Pearson correlation at significant level of P < 0.05.

According to paired t-test, HIIT resulted in significant decrease in serum levels of osteopontin (P = 0.0001) and weight (P = 0.0001), body mass index (P = 0.0001) and body fat percent (P = 0.0001) in post-test compared to pre-test. However, Covariance showed that only changes in levels of insulin (P = 0.039), weight (P = 0.001), body mass index (P = 0.005) and body fat percent (P = 0.0001) were significantly different between training and control groups. Moreover, there were negative correlation between changes in osteopontin level and changes in body mass index (P = 0.0001) and body fat percent (P = 0.044).

High intensity interval training (HIIT) decreased osteopontin level and improved body composition and metabolic status, and therefore, can be suggested as a therapeutic procedure in obese and overweight young women.

Myostatin and follistatin proteins are key proteins in the regulation of muscle tissue. Sarcopenia can lead to disruption of cellular mechanisms and the activity of these proteins. Therefore, the aim of the present study was to investigate the effect of high intensity interval training (HIIT) on muscle tissue content of myostatin and follistatin proteins in elderly rats.

In this experimental study, twelve female 20-month-old Sprague Dawley rats with an average weight of 250±30 g were selected and randomly divided into 2 groups: HIIT (n=6) and control (n=6). The HIIT program was performed 3 days a week for 8 weeks. The training protocol was 85-90% VO2max for high intensity intervals and 45-50% VO2max for low intensity intervals. Proteins content was measured by Western blotting laboratory method. Independent samples t-test was used to analyze the data.

After eight weeks of HIIT, there was no significant change in myostatin protein content in the training and control groups (P=0.49). In contrast, follistatin protein content (P=0.01) showed a significant difference (Increase).

Considering that eight weeks of HIIT could not significantly change the protein content of myostatin, but it increased the protein content of follistatin which could lead to muscle hypertrophy in elderly rats. However, HIIT as an exercise intervention for the elderly is still unknown and a lot of research on the types, duration, intensity, repetition and recovery time of HIIT is required.

Beetroot juice has been shown to increase endurance and high-intensity training performance. In addition, after consuming beetroot juice supplementation, the performance of periodic exercise in recreational (non-professional) athletes also improves. Therefore, we assessed the impact of a period of BR consumption on the performance of amateur trained soccer players following high-intensity intermittent exercise. The popularity of exercise nutrition is growing exponentially among athletes to boost their athletic performance. As a result, upon the improvement of contraction / relaxation, the generation of power and strength enhances the short-term intermittent running. Nitric oxide (NO) is a signaling molecule that is capable of improving vascular function, mitochondrial respiration, glucose homeostasis, and skeletal muscle contractions. However, the consumption of nitrate-rich vegetables (NO3-), such as lettuce, spinach, and beetroot (BR) have been identified as an alternative source and precursor of NO. The consumption of NO3- and increase of NO production decrease oxidative stress in skeletal muscle, handle calcium, and increase contractile force and production capacity in type II muscle fibers, increase time to fatigue, and improve the exercise performance. BR is rich in foods such as sugar, phenolic compounds, and ascorbic acid. BR is a rich source of NO3- commonly consumed because it possesses high contents of betacyanin and polyphenol and it produces more NO  molecules than NO salts. The ergogenic effects of NO3-rich sources were first reported in metabolic adaptations following endurance training. Athletes in team or individual sports aim to increase performance in high-intensity interval training. High-intensity exercise results in a transition from low- to high-intensity and changes in metabolic conditions. In recent years, nitrate supplementation has been shown to have a significant effect on anaerobic exercise and high-intensity interval exercise. The effect of nitrate-rich BR juice support the improvement of the performance of high-intensity intermittent exercise in team sports; however, the length of the intake period and the time interval of nitrate-rich supplementation prior to the performance of the experiment are not completely clear. Based on these findings, we hypothesized that supplementation of BR in amateur trained soccer players could improve physiological and functional parameters. Therefore, we assessed the impact of a period of BR consumption on the performance of amateur trained soccer players following high-intensity intermittent exercise.

Forty-two male soccer players competing in the 2nd Iranian amateur league with the mean age of 20.50±0.58, weight of 67.14±2.35, body fat percent of 11.63±1.44, and body mass index of 21.34±0.48 voluntarily participated in the study. First off, all participants were informed about the nature of experimental procedures, including potential risks and benefits and then, received written informed consent. The experimental protocols were approved by the Ethical Committee of Shiraz University, Iran, according to Helsinki DeclarationGuidelines. Participants were asked not to take any sport or medical supplements, or any ergogenic aids during the 4-week experiment period. The current study was randomized, placebo-controlled, cross-over, and double-blind that investigated the effect of BR supplementation on high-intensity intermittent exercise performance in soccer players. High- intensity intermittent running performance was assessed by the Yo-Yo IR1 test and Wingate test in two days. All subjects ingested beetroot juice nitrate- rich (2×70 ml/day; BR) or placebo (PLA) for six-days with seven-days of wash-out between trialsParticipants arrived at the facility 2.5 h after ingesting the last bolus of the supplement (8:30 A.M.). The heart rate was continuously monitored throughout the experiment (Polar Beat, Polar Electro, Kempele, Finland). The experimental protocols were carried out at the same time in every day. Subjects were asked to arrive to the laboratory 90 min before the experiment. They were also requested to be fully hydrated, and consume their least meal at least 3 h before the initiation of the exercise test. Besides, they had to avoid strenuous exercise 36 h before the experimental trials. Before the Yo-Yo test, warm-up was performed for each participant. The Yo-Yo test was carried out on running lanes with a width of 2 m and length of 20 m. The examination consisted of repeated 2 × 20 m runs that progressively increased the speed which was controlled by the audio bleeps from an audio system. Each 20 m running was interspersed by 5 m behind the finishing line marked the running distance that is 10-s active recovery period. Immediately after the termination of the Yo-Yo test, Subjective rating of perceived exertion was carried out in accordance with the Borgchr('39')s scale ranging from 6–20. Wingate test used for determine of power output and fatigue index. The heart rate and VO2max were measured continuously throughout the Yo-Yo test, and nitrate/nitrite plasma levels were collected prior and post of the six- days nitrate supplementation. Data are expressed as the means and standard deviation (mean ± SD). All statistical analyses were carried out by the SPSS software (version 19.0; IBM Corp, Armonk, NY, USA). The Shapiro-Wilk test , Independent t-test and Pearson correlation coefficients were used. The level of statistical significance was set at p< 0.05.

Compared to PLA, six- days BR supplementation increased mean power (483.91±23.60 vs. 468.77±23.39, p<0.05) and low power (373.31±22.03 vs. 340.41±22.40, p<0.05) and also reduced fatigue index (37.66±5.66 vs. 45.27±7.94; p<0.05). High-intensity intermittent running performance (p= 0.034), VO2max (p= 0.043), nitrate and nitrite plasma levels (P<0.001) were significantly improved in subjects in the BR compared with the PLA.

According to the results of the present study, it seems that 6 days of beet juice supplementation can improve the aerobic and anaerobic performance of trained football players.The main finding of this study is that a 6-day period of BR supplementation led to a marked improvement in the performance of high-intensity intermittent exercise in soccer players. Such an improvement includes a decrease in the heart rate during high-intensity intermittent running tests, as well as an increase in VO2max. We investigated the impact of a 6-day period of BR supplementation on nitrate/nitrite concentrations and performance during the speed and Yo-Yo tests in soccer players. After 6 days BR supplementation, the plasma levels of nitrate/ nitrite, peak power, mean power, low power, and performance in the Yo-Yo test were significantly increased. Also, the heart rate and fatigue index were significantly decreased in the BR compared with the PLA.

This study aimed to  investigate the effect of two weeks of vitamin D3 supplementation on some indices of Delayed Onset of Muscle Soreness (DOMS) after  eccentric exercise.

Method and Materials:

 In this semi experimental study, 20 nonathletic male collegiate students (19.75±1.29 years) participated in the study voluntarily and were divided randomly into two groups of experimental (n=11) and placebo (n=9). The experimental group consumed vitamin D3 (Cholecalciferol) containing 50000 IU while the placebo group took apparently similar capsules containing starch like, two capsules for two weeks. To induce DOMS, participants performed a step protocol that included four sets (5 minutes for each set), with a 1-minute of rest interval between each set using a 46 cm-step. Range of Motion (ROM) of low extremity joints and circumferences, and Visual Analog Scale (VAS were measured before, immediately after (Time 0), and 24 hours (Time 1) and 48 hours (Time 2) after eccentric exercises.

This study showed that thigh Thigh circumference increased following eccentric exercise in the placebo group, while it did not change significantly in the experimental group (p>0.05). There was no significant difference between the two study groups regarding other variables (P>0.05). Vitamin D3 supplementation with the dosage and duration used in the present study reduced the limited symptoms of DOMS. Future studies of longer duration or higher dosage of vitamin D supplementation are recommended.  

According to the finding of this study, vitamin D3 supplementation could not reduce the limited symptoms significantly. However, future studies are suggested to evaluate the effect of higher dose or longer duration of vitamin D supplementation on DOMS.

The purpose of this study is evaluation of the acute effects of high and low dosages of β-alanine on functional measures during 1km cycling time trial on female athletes. For this purpose, 30 female athletes from Shiraz participated in this study. They were randomly divided in two groups: high dosage with an average age of 24±3.047 and an average weight of 58.60±7.576; the second group was the low dosage group with average age of 23.60±3.439 and an average weight of 61.93±5.311. In the first week, Subjects ingested a placebo (orange juice) and in the second week, subjects of the low dosage group ingested 0.03 grams of β-alanine per kg of their bodyweight; While the participants in the high dosage group took 0.1 grams of β-alanine per kg. 1km cycling time trial test was conducted. Performance Time, RPE and Recovery Heart Rate was measured at rest, immediately, 4 minutes and also 10 minutes after cycling, with Performance Time obviously being measured just after. Data were analyzed using a mixed ANOVA. The results showed that RPE significantly decreased in both groups but the difference between groups was not significant. Performance Time of cycling 1 km improved in both groups that in high dosage group was significant but in low dosage group was not. Also Recovery Heart Rate measures were significantly decreased in both groups and the difference between the groups was significant . β-alanine even with a low dose can decrease heart rate and RPE But only high dosage can improve performance.

This study was aimed to compare the effect of practice with high, low, and increasing interference on accuracy and mental representation of basketball free throw. For this purpose, 30 novice participants were randomly divided into random, blocked, and increasing groups. The participants practiced the basketball free throw from different distances (3/96, 4/57, and 5.18 meter) for three consecutive days-three blocks each day and each block included 30 trials- according to the given grouping and practice order. Three days after the last training session retention and transfer tests were performed. Results showed that the increasing group had higher accuracy than the other two groups. The results during the transfer test were similar to the retention test. The results for the mental representation measure showed that the increasing group had a more structured mental representation that two other groups and this mental representation were more similar to the mental representation of the skilled participants. These results were interpreted according to the efficient processing of the information and also according to the challenge point framework

Possessing ideal dynamic balance in athletes is of crucial importance in order to improve the movement and to prevent injuries during exercises; therefore, the aim of the present  study was to assess the effect of lower limb corrective exercise along with gluteal muscle activation in  dynamic balance while treadmill running.

In the present quasi experimental design study, a total of 25 healthy active women with convenient sampling method participated in two groups of control (12 cases with average age of 21.2±2.8) and experimental (13 cases with average age of 20.5±2.5). In the experimental group, corrective exercise was performed in eight sessions during two weeks and pre and post balance test were administered for the two groups using Star Excursion Balance Test (SEBT) in three anterior, posteromedial, and posterolateral directions. Statistical analyses were performed using pair t test for within group comparison and independent t test for between group comparisons with the significance level set at 0.05.

The results showed that the two groups had no significant differences in balance indicator for different directions on pretest (P˃0.05) and within group comparisons in experimental group illustrated significant differences in anterior (P =0.008) and posterolateral directions (P = 0.011), while in posteromedial direction no significant differences were found (P˃0.05).

The results of the presented study demonstrated that this corrective exercise has probably been able to improve dynamic balance in anterior and posterolateral directions of SEBT in healthy active women possibly through having impact on gluteal muscles function, thus to this could be considerable in terms of injury preventing approaches and can be used in conditioning programs.

Correct kinematics is an effective factor to reduce musculoskeletal problems. The aim of this study was to compare muscle activity during single-leg squat (SLS) in a group with dynamic knee malalignment (DKMG) and normal cases. 23 active females (mean age of 21.86±2) participated in this comparative study. Lower limb Muscle activity (RMS), pelvic drop angle (PDA), trunk side bend (TSB) and knee valgus (KV) was recorded during SLS. Independent t test was used to compare variables and significance level was 0.05. The results showed no significant differences in PD (P=0.86) and TSB (P=0.25), but KV was greater in DKMG than the control group (P=0.00). Although %MVC of all muscles was greater in DKMG than the control group, only rectus femoris (P=0.04) and gluteus maximus (P=0.05) showed significant differences. Also, a weak correlation between KV with TSB (r=0.33) and rectus femoris activity (r= -0.37) was observed. Findings showed that DKMG had more muscle activity especially in rectus femoris and gluteus maximus which showed the important role of these muscles in controlling lower limb alignment during functional movements. Also, dynamic knee malalignment may deviate trunk towards weight bearing leg for substitution during SLS.

Proprioception, or joint position sense, probably plays an important role in joint function. A number of studies have shown that proper joint position sense can decrease the risk of injuries in sports. It is not very clear how patellofemoral pain syndrome (PFPS) can affect athletes joint position sense (JPS). Regarding the importance of proper joint position sense for movement performance and injury prevention in athletes, the aim of this study was to evaluate knee JPS in athletes with PFPS and compare it with asymptomatic individuals under non-weight bearing (sitting) conditions.
The study design was comparative in which 15 patients and 15 healthy athletes participated. JPS was evaluated by active and passive replication of knee angles for 30, 45 and 60° of knee flexion target angle while visual cues were eliminated. Each test was repeated three times. By subtracting the test angle from the replicated angle, the absolute error was calculated as a dependent variable. T-statistical test was used to compare data between two groups and P value of 0.05 was considered as the level of statistical significance.
No significant difference (P According to results, both groups had the same JPS ability, it seems PFPS does not affect the knee JPS at least in athlete cases. It would be possible that deficiency of JPS compensated for the physical activity or on the other hand, maybe pain intensity was not high enough to interfere with JPS accuracy. According to our results, PFPS doesn’t reduce IPS but further investigation is needed to disclose if other factors such as skill level, intensity of pain or joint pathology are effective on JPS accuracy or not.

Hand is one of the most important parts of the human body and is used in different action such as griping. Performing muscle activity for a long period of time leads to muscle fatigue. Thus, massaging can be used to decrease fatigue. There are a limited number of investigations that assess the effects of massage on fatigue and there is no agreement among the results of available studies. Therefore, this study was conducted to investigate the effect of effleurage massage on griping strength and endurance in fatigued, healthy, young women.
In the present study, 49 students of the School of Rehabilitation Sciences of Shiraz University, Iran, and of 18 to 30 years of age participated. The participants were selected randomly. Data were collected through maximal voluntary contraction and endurance time tests. The effect of massage and relaxation on these variables was evaluated in 2 separate sessions. Data on maximal voluntary contraction and endurance time were analyzed using paired t-test and Wilcoxon test, respectively, in SPSS software.
Grip strength reduced with fatigue and effleurage massage significantly increased grip strength in the experimental group compared to the control group (P Effleurage massage improved grip strength after muscle fatigue, but had no effect on grip endurance.

The aim of this study was assessing the effect of feedback correcting exercise in front of mirror during running on frontal plane knee and pelvic kinematic and electromyography activity of some lower extremity muscles in single leg squat (SLS). This study was quasi experimental. 23 active female subjects participated in two experimental and control groups with mean age (21.86± 2.43) years. experimental group contains subjects with knee valgus and pelvic drop angle more than a mean plus one standard deviation of the population in functional SLS. Muscular activity (RMS) of gluteus maximus, Gluteus medius, rectus femoris, vastus medialis, vastus lateralis, biceps femoris and semitendinosus, angle of knee valgus and pelvic drop were register in end of SLS Pre and post of 8 training sessions. Comparing Variable has done with independent t statistical test between 2 groups and pair sample t test within each groups with significant level of 0.05. Statistical analysis Before training showed no significant differences in pelvic drop between two groups (p≥0.05), but knee valgus angle was significantly more than control group (p≤0.05). In spit that most muscle activities (% MVC) except biceps femoris (p≤0.05), were greater in experimental group, no significant difference (p≥0.05) has seen in two groups. Comparing pre and post test has showed no significant difference in knee valgus of experimental group, however it decreased around 2 degrees and although %MVC decreased in all muscles, just rectuse femoris has shown significant difference (p≤0.05). No significant difference has seen in control group in all variables (p≥0.05). Results Findings showed poor neuromuscular control in experimental group which improved to some extent after training because lower muscle activity and energy consumption in specific movement with similar kinematic indicate improvement of motor control or cause learning. It seems mirror corrective exercise is responsible of learning by activating mirror neurons. Also decreasing muscular activity in movements cause decreasing fatigue, so possibility of injury may decrease, regarding the relation between fatigue and most injuries. Although there is some evidence that this training may cause positive changes in knee valgus and lower limb neuromuscular activity but more researches are needed to reach certain results.