Iranian Journal of Health And Physical Activity
Volume:1 Issue: 1, 2010

The goal of this investigation was to compare functional fitness factors following water and land exercise in elderly men. Thirty elderly men aged 63-70 were randomly selected and divided into two groups. Pre- and post-intervention tests of lower limb muscle''s strength, walking ability, lower limb flexibility, static and dynamic balance were conducted. Measures included 30-second chair stand, eight-feet time up and go, chair sit-and-reach test, the Sharpened Romberg Test, Functional Reach Test (FRT), Functional Reach Right (FRR) and Functional Reach Left (FRL) Tests. Next, both groups participated in a water or land exercise program. At pre-test there was no. significant difference between the two groups'' functional fitness factors (p<0.05); however, at post-test, the groups differed on their functional reach left test with the water exercise group showing better performance than the land exercise group (p<.0.05). There was also significant differences between pre- and post-test results of the water exercise group on all the tests (p<.0.05). The land exercise group showed significant differences from pre- to post-tests on muscle strength, walking ability, static balance with open and closed eyes, FRT, FRR, and FRL (p<.0.05). Although the results support the positive effects of water and land exercise on functional fitness factors for male elders, water exercise proved to be more beneficial than land exercise in improving the elders'' physical capability to maintain their body balance.

Self-confidence can be defined as the belief in one’s abilities to achieve success, and it often has been identified as a most important mental skill for success in sport by individuals engaging in competitive sports, including athletes and coaches. This study examined the relationship between sources of sport confidence and athletic performance in young Iranian elite wrestlers. The participants were 148 elite wrestlers of 17 to 20 year olds (M=18.60, SD=0.98) participating the country championship in 2009, who completed the Sources of Sport Confidence Questionnaire (SSCQ). Athletic performance of young wrestlers, which acquired their rank in the championship, was taken into account. The results showed a significant positive relationship between coaches’ leadership, mastery, environmental comfort, demonstration of ability, physical/mental preparation, physical self-presentation and athletic performance. The results of a stepwise regression analysis showed that coaches’ leadership was the strongest predictor of athletic performance. Our findings suggest that coaches’ behaviors may greatly influence athletes’ self-confidence and can be an important social factor that influences athletes’ cognition and behavior.

Muscle fiber conduction velocity (MFCV) decreases during sustained fatiguing contraction due to metabolic accumulation. Differences in morphological and architectural characteristics of muscle fibers within the vastus medialis muscle may result in non-uniform metabolites accumulation and as consequence non-uniform changes in fiber conduction velocity. The aim of this study was to assess muscle fiber conduction velocity at the level of single motor unit in different locations of the vastus medialis muscle during sustained contraction. Surface and intramuscular EMG signals were recorded from two locations of the right vastus medialis muscle of ten healthy men during 70s isometric contraction at 20% of the maximal force. The distal location of the vastus medialis muscle resulted in a larger value of conduction velocity (p < 0.05) and greater conduction velocity rate of reduction (p < 0.05) during sustained contraction compared with the proximal region. These results indicated a non-uniform change in electrophysiological membrane properties at different locations of the vastus medialis muscle during sustained contraction.

We tested the electromyography (EMG) activities of the oblique and longus parts of the vastus medialis and vastus lateralis muscles before, 24 and 48 h after eccentric exercise. Surface electromyographic signals were recorded from the oblique and longus parts of the VMO and VLO muscles of the right quadriceps muscle of 10 healthy men during sustained contraction of 50% MVC, before, 24 and 48h after eccentric exercise. The eccentric exercise was performed with a KinCom Isokinetic Dynamometer (Chattanooga, TN) and comprised four bouts of 25 maximum voluntary concentric/ eccentric knee extension contractions at a speed of 60 deg/s. Average rectified value (ARV) was estimated from the EMG signals for epochs of 1s, and were averaged over intervals of 10% of the time to task failure. Maximal voluntary force and time to task failure were reduced (p < 0.001) following eccentric exercise. ARV reduced over sustained contraction for both VMO and VLO muscles (p < 0.05). ARV rat of reduction over time for VMO was greater than VLO muscle (p < 0.05). The results indicate a greater effect of eccentric exercise on VMO than on VLO muscle.

The effects of physical activities such as jogging, running and bicycling on arteriosclerosis risk factors are well documented. However, the effect of moderate swimming exercise on arteriosclerosis risk factors and particularly oxidized low-density lipoprotein (OX-LDL) has received little attention. It was hypothesized that moderate swimming exercise reduces OX-LDL level and others arteriosclerosis risk factors in hypertensive postmenopausal women. Thirty-four hypertensive postmenopausal women were randomly divided into control and training groups. Swimming training was conducted four times per week for 30 min at 60-70% of maximum heart rate for eight weeks. Moderate swimming training resulted in a reduction in systolic blood pressure (p<0.05) and oxidized low-density lipoprotein (p<0.05). No changes were observed in vascular cell adhesion molecule (VCAM-1), diastolic blood pressure low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C). A positive correlation was also found between OX-LDL and systolic blood pressure (R =0.34, p<0.05) and LDL-C (r = 0.5, p<0.05). In conclusion, moderate swimming training may reduce systolic blood pressure and OX-LDL in hypertensive postmenopausal women.

Strengthening of the oblique portion of the vastus medialis muscle (VMO) by moderate isometric exercises, particularly at the early phase of rehabilitation program for acute knee injury is an important part of knee rehabilitation protocols. The goal of this study was to investigate whether moderate sustained isometric exercises at level of 20% and 30% MVC activate the oblique portion of the VMO to a significantly greater extent than longus part (VML) of this muscle. Nine healthy men with no history of knee injury were tested; Multi-channel surface EMG signals were recorded from vastus medialis oblique and vastus medialis longus of the right leg during 70-s isometric contractions at 10%, 20% and 30% of the maximal force using controlled laboratory study. Average Rectified Value (ARV) and Mean Power Frequency (MPF) computed from the surface EMG were significantly increased with contraction intensity for both VMO and VML muscles (P < 0.05). However, the rate of change over time in ARV and MPF were significantly greater for VMO than VML (P < 0.05). Moderate sustained isometric exercise at 20% and 30% MVC was effective in activating the medial stabilizer of the patella, and therefore, it may be used at the early phase of rehabilitation program to establish patella control as stable base for knee rehabilitation.

The aim of this study was to investigate the effects of two different methods of concurrent training on body composition, aerobic power and muscular endurance. The volunteers performed aerobic and resistance training as two different methods of concurrent distinct endurance-resistance (CDER) and concurrent parallel endurance-resistance (CPER) for 12 weeks. The control group performed no regular exercise during this period. Body fat significantly reduced in both CDER and CPER after 12 weeks of training, compared to the control group (p<0.05). During the post training session, pull-up and sit-up records in both CDER and CPER were significantly higher than in the pre-training session and in the CDER group was higher than that in the CPER group (p<0.05). Moreover, VO2max significantly increased after 12 weeks, during which time the CDER group showed a higher increase in VO2max as compared with the CPER group (p <0.05). These results indicated that concurrent distinct endurance-resistance is more effective in improving aerobic power, while concurrent parallel endurance-resistance may be useful for improving body composition and muscular endurance

Interleukin-6 (IL-6) is excreting by adiposities, which increases by overweight and obesity. Obesity-related inflammatory marker is a risk factor for diseases. It has been reported that diet-induced weight loss lowers IL-6 levels. The effect of exercise training and other therapies on IL-6 is still unclear. We examined the effects of two weight loss protocols on plasma concentration of IL-6 in a sample of overweight and obese healthy sedentary female college students (N = 30; BF =29.53±3.1%, and BMI = 29.04±2.22 kg/m2), who were randomly assigned into three experimental and one control groups. Experimental Group I experienced twelve-day researchers'' proposed diet (D); Experimental Group II experienced twelve-day researchers'' proposed diet along with twelve-day running training every other day mid consumption 250cc water beverage during per aerobic exercise period (AEDW), Experimental Group III experienced twelve-day researchers'' proposed diet along with twelve-day running training every other day and the consumption of 250cc 12% glucose beverage during each aerobic exercise (AEDG). The control group (C) remained sedentary with a normal diet. Total body weight in all three experimental groups was reduced (p<0.001). Also, IL-6 levels were significantly decreased, for both AEDW and AEDG groups (f = 22.962, p =0.022) in comparison with the control group, but significant decrease in resting levels of IL-6 in AEDW group was more than AEDG (p<0.001 vs. p<0.022). There was no significant change in the D and control group (f = 22.962, p= 0.781). After doing the exercise and enforcing diet protocols, AEDW and AEDG groups lost weight and showed a decrease in their resting IL-6 plasma concentration. These protocols are optional for decreasing resting plasma IL-6 levels and prevent prevalence disease as cardiovascular disease.

We examined leg length difference (LLD), varus and valgus knee and foot deformities in athletes with and without patellofemoral pain syndrome (PFPS). Twenty three healthy participants (seven women and 16 men) and 15 participants (three women and 12 men) with PFPS aged 20-30 participated in the study. Leg length difference, genu varum, genu valgum, foot pronation and flat foot were measured and the groups were compared. No significant differences were found in LLD, genu varum, genu valgum, foot pronation and flat foot between the two groups. Our findings suggest that abnormal biomechanics of lower limb do not increase the risk of PFPS.