Research in Sport Medicine and Technology
Year:2020 | Volume:9 | Issue:18 |Papers Count:6

Muscle atrophy is one of the consequences of aging and sports activities may prevent it. The aim of this study was to evaluate the effect of high intensity interval training on gene expression of Tweak and Fn14 in EDL muscle of aged C57bl/6 mice. For this purpose, 28 male C57bl/6 mice aged (n=14) and adult (n=14) were assigned in two groups of training (n=7) and control (n=7). After one-week familiarization, training groups participate in 4 weeks high intensity training program on treadmill, with an intensity of 85% of the maximum speed in the first week up to 95% of the maximum speed in the last week, in 2-minute intervals (6 in the first week to 10 in the last week) with 1 minute rest between intervals. 48 hours after the last training session, the mice were sacrificed. Then gene expressions of Tweak and Fn14 in EDL muscle were measured. The findings show that aging has significant effect on EDL muscle weight (P=0. 032). Also the results showed that with increasing age Tweak and Fn14 mRNA expression increased in the EDL muscle (P=0. 001 and P=0. 002 respectivly). On the other hand, training can reduce Tweak and Fn14 gene expression in both old and adult groups (P=0. 001). On the other hand, although training slightly increased EDL muscle weight in both adult (P=0. 117) and old (P=0. 321) groups, this value statistically was not significant. Thus, aging is associated with an increase in Tweak and Fn14 mRNA expression, which could possibly be involved in muscle weight changes associated with aging. Since that high intensity interval training decrease these mRNA expression, can might be utilized HIIT for maintenance aging and adult of muscle mass.

Genu varus is one of the malalignment of the lower limbs, the failure to correct it leads to secondary abnormalities in adulthood. The purpose of this study was to investigate the effects of a corrective exercise program on ground reaction forces, loading rates, impulses and free moment during stance phase of walking. 17 children with genu varus were volunteered to participate in this study (Age: 11. 71± 1. 68 years, Height: 1. 40± 0. 09 meter, Weight: 35. 14± 11. 47 Kg, and BMI: 17. 49± 3. 61Kg/M 2 ). Ground reaction forces were recorded with two Kisler force plates during pre and post-test. At the dominant limb, the amount of time to peak in the mediolateral ground reaction force component during heel contact decreased by of 61. 90% (P=0. 011). Also, the time to peak of the vertical ground reaction force component during mid-stance tend to increase significantly by 11. 47% during the post-test compared to the pre-test (P=0. 063). The values of peak ground reaction force components, loading rate, impulse and free moment did not show any significant differences between pre and post-test. The findings showed that the corrective exercise trainings used in the present study had the most effect on the time to peak components of the GRF, but there were no significant effects on the loading rate, impulses, and free moment components. The corrective exercises used in the present study have had the most effect on the time to peak of ground reaction forces and improve them. On the other hand, these exercises did not have any significant effect on the vertical loading rate, impact and free moment values.

Determining the best rest interval durations between resistance exercise sets for adaptation is very important. This study investigated the effect of different rest intervals duration between resistance exercise (RE) sets on the gene expression of CGRP and IGF-1. Forty two male Wistar rats were randomly divided in to 7 groups. The resistance exercise included one session of climbing on one meter ladder with 26 steps. Exercise included 4 sets of 5 repetitions with an overload of 150 percent of the rat's body weight and 30, 60, 90, 120, 150 and 180 seconds rest intervals. The qRT-PCR technique was used to evaluate the gene expression of CGRP and IGF-1. The gene expression of CGRP in soleus muscles following RE with rest intervals of 30 (P=0. 001), 60 (P=0. 001) and 90 seconds (P=0. 001) were significantly lower than 120, 150 and 180 seconds. However, there were no significant differences in the gene expression of IGF-1 among all groups (P=0. 12). Based on our results, it seems that these rest interval domains can be addressed as a cut point of gene expression for the strength and hypertrophy developing process at the cellular level.

The aim of this study was comparing professional futsal practice sessions with and without blood flow restriction on angiogenesis and angiostatin stimulation in active young men. Among physical education students, 12 volunteer selected and randomly divided into two groups of exercise with and without blood restriction. All of the subjects did the 3 vs. 3 professional futsal practice in 6 repetition of two minutes. One minute determined as resting time between the repetitions. In exercise group with blood restriction, a cuff on the thighs with pressure of 140 Mm Hg were applied. The blood samples were collected before and after the exercise sessions to determine the ratio and values of VEGF and endostatin concentration. Elisa method was used to measure the variables. To determine within and between group differences, Paired T test and Independent T test were used respectively at significance level of 0. 05. The results showed no significant differences for the measured variables between the groups. However, VEGF significantly decreased in the two groups after exercise session (P=0. 002). The ratio of VEGF to endostatin significantly increased in exercise with blood flow restriction group (P=0. 002), but not in the Exercise group (P=0. 006). Interestingly, the endostatin concentration increased significantly after the trial (BFR: P=0. 003, NONBFR: P=0. 005). Blood lactate was significantly higher in exercise group with blood restriction(P=0. 003). In conclusion, a professional futsal practice session can decrease blood level of VEGF and increase its endostatin.

The most commonly used empirical approach to address issues of attention constraint is evaluate the degree of interference in dual or multiple tasks. The purpose of this study was designing software to estimate the relative interference between multiple tasks and determine its validity in performance prediction of simultaneous multiple tasks. in order to assess the validity of software, 46 students with a driving certificate from East Tehran branch of Islamic Azad University were selected by available sampling method, the response time to the visual and auditory stimulus of participants during driving in different conditions was measured by using software and hardware installed on their cars, and then relative interference in the above mentioned conditions was estimated by using relative interference software. The result of pearson correlation analysis showed that there is a high, meaningful and direct correlation between the amount of estimated relative interference with the software and measured participants' response time in different driving conditions (r=0. 95, p≤ 0. 01). Therefore, the designed software can be used to predict the amount of interference between two or more simultaneous tasks.

hronic low back pain is one of the most common musculoskeletal problems. This disease, in addition to causing pain and disability affects the gait parameters in patients. The purpose of this study was to investigate the effect of aquatic exercises therapy on the severity of pain, disability and Spatiotemporal parameters and kinetic of gait in women with chronic low back pain. Twenty-four women with chronic low back pain (with a mean age of 26. 6 years) participated in this study. The exercise protocol was conducted in water for 8 weeks. The severity of pain and disability were measured by Quebec and Oswestry questionnaires respectively. gait parameters were evaluated using a foot pressure device. Aquatic exercises therapy significantly decreased pain and disability severity and significantly improved gait parameters in the experimental group (p≤ 0. 05). Fore there more, the significant difference between the variables in the posttest was obtained between experimental and control groups (p≤ 0. 05). No significant difference was observed between the pre-test and post-test comparisons in the control group (p≥ 0. 05). Regarding the reduction of pain and disability and improvement of gait parameters after eight weeks’ intervention in experimental group, the use of this protocol is recommended to improve patients with chronic low back pain as a new method.