Asian Journal of Sports Medicine
Volume:3 Issue: 4, Dec 2012

To date, little is known about the effects of a reduced level of jumping exercise regimens on bone turnover markers and mass. This study investigates the effects of different jumping exercise regimens with varying exercise loads on serum bone turnover markers and bone mass in female rats. A total of 144 female rats aged 12 weeks, were divided into 12 groups as follows: no exercise for 8 (8S) or 32 weeks (32S), or 8 weeks of standard training program (8STP) consisting of 200 jumps per week (200J/w), given at 40 jumps per day (40J/d) for 5 days per week (5d/w) (8STP24E), followed by 24 weeks of exercise at loads of either 10J/d or 20J/d or 40J/d, for either 5d/w, or 3d/w, or 1d/w. Serum osteocalcin, alkaline phosphatase, C-terminal telopeptide of type 1 collagen (1CTP) concentrations, and tibial fat free dry weight were measured. Tibial mass was significantly higher in 8STP than 8S. No changes were evident in serum markers of bone turnover parameters after 8STP. Significant increases in tibial mass were observed in rats that continued to exercise at workloads of 30J/w and above after 8STP. Serum alkaline phosphatase concentrations increase whereas serum 1CTP concentrations decrease in rats given workloads of 40J/w and above.

The purpose of this investigation was to assess the effects of listening to music during warm-up on short-term supramaximal performances during the 30-s Wingate test in highly trained athletes. Twelve young male athletes (20.6±1.8 yrs, 177±4.4 cm and 72.3±5.3 kg) underwent two Wingate tests in separate sessions with a recovery period of 48 h in-between, either after a 10 min of warm-up with (MWU) or without (NMWU) music. High tempo music (> 120 to 140bpm) was selected for the study. Heart rate (HR) and rate of perceived exertion (RPE) were recorded after the warm-up (for HR = average of warm-up) and immediately after the Wingate test. HR, RPE and the fatigue index during the Wingate test are not affected by the incorporation of music during warm-up. However, power output (Ppeak and Pmean) was significantly higher after MWU than NMWU (p < 0.05). The relative increases were 4.1 ± 3.6 and 4.0 ± 3.7 W·kg-1 for Ppeak and Pmean respectively. These findings demonstrated the beneficial effect of music during warm-up on short-term supramaximal performances. As it’s a legal method and an additional aid, music may be used during warm-up before performing activities requiring powerful lower limbs’ muscles contractions during short-term supramaximal exercises.

Prolonged physical exercise results in transient elevations of biochemical markers of muscular damage. This study examined the effect of short-term maximal exercise on these markers, homocysteine levels (Hcy), and total antioxidant status (TAS) in trained subjects. Eighteen male football players participated in this study. Blood samples were collected 5-min before and 3-min after a 30-s Wingate test. The results indicated that plasma biochemical markers of muscle injury increased significantly after the Wingate test (P<0.05). Moreover, significant increase of white blood Cells and their main subpopulations (i.e. monocytes, neutrophiles, and lymphocytes) (P<0.001) has been observed. Likewise, uric acid, total bilirubin, and TAS increased significantly after exercise (P<0.05). However, Hcy levels were unaffected by the Wingate test (for 3-min post-exercise measurement). Short-term maximal exercise (e.g. 30-s Wingate test) is of sufficient intensity and duration to increase markers of muscle damage, and TAS; but not Hcy levels. Increases in the selected enzymes probably come primarily from muscle damage, rather than liver damage. Moreover, increase of TAS confirms the Wingate test induced oxidative stress.

The aim of the present study was to investigate associations between skeletal muscle mass, body fat and training characteristics with running times in master athletes (age > 35 years) in half-marathon, marathon and ultra-marathon. We compared skeletal muscle mass, body fat and training characteristics in master half-marathoners (n=103), master marathoners (n=91) and master ultra-marathoners (n=155) and investigated associations between body composition and training characteristics with race times using bi- and multi-variate analyses. After multi-variate analysis, body fat was related to half-marathon (ß=0.9, P=0.0003), marathon (ß=2.2, P<0.0001), and ultra-marathon (ß=10.5, P<0.0001) race times. In master half-marathoners (ß=-4.3, P<0.0001) and master marathoners (ß=-11.9, P<0.0001), speed during training was related to race times. In master ultra-marathoners, however, weekly running kilometers (ß=-1.6, P<0.0001) were related to running times. To summarize, body fat and training characteristics, not skeletal muscle mass, were associated with running times in master half-marathoners, master marathoners, and master ultra-marathoners. Master half-marathoners and master marathoners rather rely on a high running speed during training whereas master ultra-marathoners rely on a high running volume during training. The common opinion that skeletal muscle mass affects running performance in master runners needs to be questioned.

To assess the anthropometric characteristics and dietary intake of the Greek national cross-country skiing team. Thirty-three athletes (10 females aged 20 ± 5 years; 23 males aged 20 ± 6 years old) participated in the study. All athletes were members of the Greek national ski team, and they had been selected to take part in the Winter Olympics, World Ski Championships, European Ski Championships or other international events, according to their performance. Body composition was estimated by bioelectrical impedance (BIA) and skinfold thickness. The athletes recorded their physical activity and dietary intake for 3 training days, and on a competition day. The female skiers had 14.2±1.9% body fat, the men 11.0±1.5% body fat. Female athletes consumed a diet of 1988±319 Kcal during training days and 2011±330 Kcal during competition days. Male athletes consumed 2255±790 Kcal and 2125±639 Kcal respectively. These values are below those recommended for highly active people. During the training period, carbohydrate, fat and protein contributed to 44.5±7.1%, 39.2±5.3% and 16.1±3.7% of the total energy intake (EI) respectively for the males, and to 52.8±5.6%, 33.0±3.7% and 14.3±2.5% of the EI of the women. Between training and competition days, men demonstrated an increased carbohydrate and reduced fat consumption when competing (P<0.001 for both). Women, on the other hand, consumed more carbohydrate and less protein during competition days (P<0.05 for both). Protein intake was within the recommended range for both males and females, but fat exceeded the recommended values and was consumed at the expense of carbohydrate. Vitamins B12, D, E and K, biotin, folate, Ca, Mg, K, I were inadequately consumed (below the RDA) by both women and men, while the women also exhibited inadequate intakes of iron and the men of manganese. The inadequate energy and nutrient intake in the Greek national cross-country ski team could put the athletes at risk of nutritional deficiencies, and possibly compromise their athletic performance.

The 1-repetition maximum (1-RM) test is the gold standard test for evaluating maximal dynamic strength of groups of muscles. However, safety of actual 1-RM testing is questionable in clinical situations such as type 2 diabetes (T2D), where an estimated 1-RM test is preferred. It is unclear if acceptable test retest reliability exists for estimated 1-RM test in middle aged T2D patients. This study examined the reliability of the estimated 1-RM strength test of untrained middle aged T2D subjects. Twenty five untrained diabetic males (n=19) and females (n=6) aged 40.7+0.4 years participated in the study. Participants undertook the first estimated 1-RM test for five exercises namely supine bench press, leg press, lateral pull, leg extension and seated biceps curls. A familiarisation session was provided three to five days before the first test. 1-RM was estimated for all participants by Brzycki 1-RM prediction equation. Another identical 1-RM estimation procedure occurred one week after first test. Intraclass correlation coefficients (ICC), paired t-test, standard error of measurement (SEM), Bland-Altman plots, and estimation of 95% CI were used to assess reliability. Test-retest reliability was excellent (ICC2,1=0.98-0.99) for all measurements with the highest for leg extension (ICC2,1=0.99). The SEM was lowest for lateral pull and leg extension exercises. Paired t-tests showed non-significant differences between the means of 2 sessions across three of five exercises. The study findings suggests that estimation of 1-RM is reliable for upper and lower body muscular strength measurement in untrained middle aged T2D patients.

Ankle sprain is one of the most common injuries among athletes and Instability and injury to this joint is responsible for almost long time lost from physical and recreational activity. Also it can impose high cost to sport teams. Prevention of this injury is an important concern of practice and rehabilitation. One way of reducing the possibility of ankle joint injury is using ankle orthosis. The present study aimed at inspecting the effects of two ankle orthoses on dynamic and semi-dynamic postural stability in athletes with chronic ankle instability. Twenty basketball players with CAI and fifteen non-injured athletes volunteered to participate in this study. Biodex Balance System was used to assess the participants’ postural stability in bilateral position at level 8 and level 2. Repeated measures analyses variance (ANOVA) was performed in order to examine the effects of ankle orthoses. Statistical significance level was determined at P< 0.05. statistical analyses revealed the significant effect of ankle supports on dynamic and semi-dynamic postural stability in the two groups and results indicated there wasn’t significant difference between groups. According to our results the orthoses improved both dynamic and semi-dynamic postural stability. Therefore orthoses can prevent of injury and its reoccurrence

The purpose of this study was to evaluate the effect of an eight-week progressive resistance training and vibration program on strength and ambulatory function in multiple sclerosis (MS) patients. Twenty-Four female MS patients with the following demographics: age 27-45 years, and expanded disability status scale (EDSS) 2-4, participated in this study. The subjects were randomly allocated to one of two groups. The exercise group (n=12) trained according to a progressive program, mainly consisting of resistance training and vibration, three times a week for eight weeks and compared with subjects in the control group (n=12) that received no intervention. Subjects completed one set of 5-12 reps at %50-70 maximal voluntary contraction (MVC). After 5-10 minutes rest, six postures on plate vibration were done. Isotonic MVC of knee extensors, abduction of the scapula and downward rotation of the scapular girdle muscle groups were predicted by using the Brzycki formula. Right leg balance (RLB), left leg balance (LLB), and walking speed (10-Meter Walk Test) were assessed before and after the training program. Descriptive statistics and Co-variance were used for analyzing data. After eight weeks of training the exercise group showed significant increase in MVC of Knee extensors (32.3%), Abduction of the scapula (24.7%) and Downward Rotation Scapular (39.1%) muscle groups, RLB (33.5%), LLB (9.5%), and decrease in 10-Meter Walk Test (10MWT) (9.3%), (P<0.05). The results of this study indicated this type of training can cause improvements in muscle strength and functional capacity in patients with multiple sclerosis.

This study was performed to determine the possible causes and mechanisms of fatalities among Iranian mountaineers during climbing. By contacting several sources, deceased mountaineers were identified. Data about the causes and mechanism of death was retrospectively obtained using a standard questionnaire for each case. A total of 29 deaths were identified from March 2006 to June 2010. Deceased subjects had a mean age of 39 years (SD: 12.8, Range: 20-67). Falling was the most common accident leading to death of outdoor enthusiasts (n=14, 48%). Asphyxia (n=6, 24%) was the most common cause of death among the subjects, followed by heart attack, internal bleeding, cerebral hemorrhage and hypothermia (17%, 17%, 17% and 10%, respectively). Our findings suggest that education of medical service providers of the climbing groups on facing victims in high altitude areas, where they have limited resources, can be particularly helpful. In addition, a national program to educate mountaineers might help to reduce fatalities.

Many factors such as lumbar instability and spinopelvic alignment are associated with low back pain. Our purpose was to analyze the pelvic incidence - one of spinopelvic alignment parameters- and spine instability correlations in patients with chronic low back pain. Fifty-two patients suffering from chronic low back pain entered this case control study. Lateral spine radiography was taken from patients. pelvic incidence and L3, L4 and L5‘s vertebral body width were measured for all patients, and lumbar instability was evaluated in 3 different levels: L5-S1, L4-L5 and L3-L4. Thirty-two patients having lumbar instability formed group A and 20 patients without lumbar spine instability allocated to group B. Average age, mean weight, height, body mass index and mean vertebral width of both groups did not differ meaningfully. Pelvic incidence‘s mean amounts set to 53.9 in group B and 57.7 in group A without any significant difference; but pelvic incidence was significantly lower in patients with lumbar instability of L5-S1 origin (P=0.01). Overall, pelvic incidence did not differ between two groups. However, separate evaluation of each level revealed lumbar instability of L5-S1 segment to be associated with lower pelvic incidence.

This study aimed to assess the rate of tobacco consumption among professional athletes in Iran and assessing their knowledge and attitude in this regard. A total of 738 athletes from 10 different types of sports were evaluated. Athletes were all members of the priority leagues. After obtaining consent from the Physical Education Organization and coordination with the related federations, athletes were asked to fill out the standard questionnaire. All understudy subjects were males. The mean age was 28.4±2.7 yrs. The mean age of initiation of sport in these subjects was reported to be 12.3±4.01 yrs. A total of 178 (24.6%) subjects had experienced cigarette smoking and 308 (42.3%) had experienced hookah smoking. Sixty four subjects (9%) were current smokers. The mean score of knowledge about hazards of smoking was 5.6±0.9 among those who had experienced smoking. This score was 7.9±0.5 among those with no smoking experience (P=0.04). Rate of smoking among professional athletes is lower than general population average. So participation in organized sports may be a protective factor against tobacco use in people. Percentage of smoker athletes was significantly higher in individual sports compared to team sports. Experiencing hookah smoking was significantly higher than cigarette smoking among athletes. Athletes had good knowledge about hazards of smoking and had a positive attitude in this respect. Further studies are needed to evaluate reasons of cigarette and hookah smoking among athletes.