Asian Journal of Sports Medicine
Volume:5 Issue: 1, Mar 2014

There is a relationship between exercise and changes in immunity. So athletes are prone to different medical problems such as injuries and infections. Infection is an important medical problem which could be a reason for athletes’ absence from training. The relationship between physical activity and immune system, characteristics of different types of infections in athletes with emphasis on special clinical presentations or complications, time to return to physical activity and training and strategies to prevent development and transmission of infections in athletes or physically active people are the main topics of this review.

Lower limb skin-fold thicknesses have been differentially associated with sex in elite runners. Front thigh and medial calf skin-fold appear to be related to 1,500m and 10,000m time in men but 400m time in women. The aim of the present study was to compare anthropometric and training characteristics in recreational female and male half-marathoners. The association between both anthropometry and training characteristics and race time was investigated in 83 female and 147 male recreational half marathoners using bi- and multi-variate analyses. In men, body fat percentage (β=0.6), running speed during training (β=-3.7), and body mass index (β=1.9) were related to half-marathon race time after multi-variate analysis. After exclusion of body mass index, r2 decreased from 0.51 to 0.49, but body fat percentage (β=0.8) and running speed during training (β=-4.1) remained predictive. In women, body fat percentage (β=0.75) and speed during training (β=-6.5) were related to race time (r2=0.73). For women, the exclusion of body mass index had no consequence on the predictive variables for half-marathon race time. To summarize, in both female and male recreational half-marathoners, both body fat percentage and running speed during training sessions were related to half-marathon race times when corrected with co-variates after multi-variate regression analyses.

This study aimed to compare physiological responses and time-motion analysis between official and simulated karate combat. Ten high-level karatekas participated in this study, which included official and simulated karate combat. Karatekas used more upper-limb attack techniques during official combat compared to simulated ones (6±3 vs 3±1; P=0.05, respectively). For official and simulated karate matches, the numbers of high-intensity actions (i.e. offensive and defensive fighting activity) were 14±6 and 18±5, respectively (P>0.05), lasting from <1s to 5s each. Total fighting activity phase was lower during official compared to simulated matches (21.0±8.2s vs 30.4±9.9s, P<0.01, respectively). Effort (10.0±2.8s) to rest (11.9±2.7s) ratio (E:R) was 1:1 and high-intensity actions (1.6±0.3s) to rest (11.9±2.7s) ratio was higher than 1:7 during simulated combat. During official karate match, the activity and rest duration were 10.0±3.4s and 16.2±4.1s, respectively (E:R ratio 1:1.5), while high-intensity actions were 1.5±0.3s, resulting in an E:R ratio of 1:11. Blood lactate concentration was higher during official (11.14±1.82 mmol.l-1) compared to simulated karate combat (7.80±2.66 mmol.l-1) (P<0.05). Subjective perceived exertion differed significantly between official and simulated combat (14±2 vs. 12±2; P<0.05, respectively). The majority of karatekas’ perceived exertion was higher in the lower limb muscle groups irrespective of the karate combat condition. Official and simulated matches differ considerably, therefore coaches should create new strategies during training sessions to achieve the same effort and pause profile of competitive matches and/or that athletes should be submitted to frequent competitions to adapt themselves to the profile of this event.

The aim of this study was to compare the effect of resistance exercise with three different methods on integrated electromyography (IEMG) and metabolic responses in recreational athletes. Twenty four males (mean 23.59±0.87 years) were randomly assigned to three experimental groups. Participants performed knee extension exercises: Slow (SL: 3-3, 3s for each concentric and eccentric action with 50% of 1 RM), Normal (NH: 1-1, 1 s for each concentric and eccentric action 80% of 1 RM) and Traditional (TH: 2-4, 2s for concentric and 4s for eccentric action with 80% of 1 RM). Plasma lactate, glucose and triglyceride concentration and IEMG was measured before and immediately after performing four sets of resistance exercise. Each method significantly decreased IEMG (P<0.05), but there was no significant difference between groups. Lactate was increased following TH and NH more than SL method (P<0.05). Each method significantly increased plasma glucose (P<0.05). Work considering time under tension (workTUT) was higher (P<0.05) during TH method than the other methods and during SL it was higher than NH method (P<0.05). Volume load was higher (P<0.05) during NH than the other two methods and during TH it was higher than SL method (P<0.05). These results indicate that exercise intensity during the resistance exercise is important for the enhancement of lactate responses, but the slow resistance exercise method could induce acute neuromuscular response as much as high intensity methods. It seems that this method will be advantageous for those who want to increase acute neuromuscular changes with low exercise intensity and volume.

Air pollution has remained a major health concern in Kolkata. The present study was carried out to analyze the association between the levels of air pollutants and pulmonary function of youngster footballers living in two different air pollutant zones of Kolkata, West Bengal. Air pollution data of the two ambient air quality-monitoring stations located at Rabindrabharati and Victoria Memorial was collected for the period from January 2012 to March 2012. Study was conducted on two hundred and twenty boys of the age range 14-16 years living within 3km radius of the two monitoring stations. Sample consisted of 60 footballers (30 from Rabindrabharati and 30 from Victoria Memorial) and 160 sedentary boys (80 from Rabindrabharati and 80 from Victoria Memorial). They were investigated for their spirometric lung functions by the method and technique recommended by American Thoracic Society. Results were expressed as mean ± SD and independent samples T test was conducted to compare between two groups. Results revealed that particulate matter (PM10), oxides of sulfur (SO2) concentrations were significantly higher in Rabindrabharati zone, whereas no significant differences were noted in oxides of nitrogen (NO2) and carbon monoxide (CO) concentrations though values were higher at Rabindrabharati than Victoria Memorial. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), forced mid expiratory flow (FEF25-75%), maximum voluntary ventilation (MVV) were significantly lower both in footballers (P<0.05) and sedentary boys (P<0.01) of Rabindrabharati zone. Exposure to high air pollutant concentration might be associated with reduced pulmonary function in both sedentary and trained boys in spite of the fact that regular participation in training program may improve pulmonary function.

The aim of the present study was to examine the variation in physical activity of elite soccer players within successive prolonged periods of fixture congestion over 5 months of competition during the competitive season 2011-2012. Sixteen international players, classified into 6 positions (central defenders: CD; full-backs: FB; central defensive midfielders: CDM; wide midfielders: WM; central attacking midfielders: CAM; forwards: FW), were examined during the French First League, French Cup, and UEFA Champion’s League matches. The total distance covered at light (<12 km.h-1), sustained-cruising (>18-21 km.h-1), high (>21-23 km.h-1), very high (>23-25 km.h-1), sub-maximal (>25-27 km.h-1), and maximal (>27 km.h-1) intensity running (IR) were measured and analysed using a semi-automatic match analysis system (Amisco Pro™). No differences were observed between congested and non-congested periods (two vs. one match a week, respectively) for the total distance covered at all the speed thresholds over 18 km.h-1, with no variation in physical fitness over the 5 studied months. Specifically to the playing positions, regardless of the congestion periods, FB and WM covered more distance than CDM over 21km.h-1; FB, WM and FW covered similar distances for all running intensities; and CD and CDM covered shorter distance during non-congested compared to congested periods (P<0.05) at light-IR. The present study reveals that prolonged congested match fixture did not affect the high-intensity physical activity of top-class soccer players during official games during a 5 months fixture period.

L-glutamine is the most abundant amino acid found in human muscle and plays an important role in protein synthesis and can reduce the levels of inflammation biomarkers and creatine kinase (CK) after training sessions. Delayed onset muscle soreness (DOMS) develops after intense exercise and is associated with an inflammatory response. The purpose of this study was to investigate the effect of glutamine supplementation on surface electromyography activity of the vastus medialis muscle (VMM) and rectus femoris muscle (RFM) and levels of creatine kinase after an eccentric contraction. Seventeen healthy men (age: 22.35±2.27yr; body mass: 69.91± 9.78kg; height: 177.08±4.32cm) were randomly assigned to experimental (n=9) and control groups (n=8) in a double-blind manner. In both groups, subjects were given L-glutamine supplementation (0.1g.kg-1) or placebo three times a week for 4 weeks. Median frequency (MDF) and mean power frequency (MPF) for VMM and RFM muscles and also CK measurements were performed before, 24h and 48 h after a resistance training session. The resistance training included 6 sets of eccentric leg extensions to exhaustion with 75% of 1RM. There was no significant difference between groups for MDF or MPF in VMM and RFM. The difference of CK level between the groups was also not significant. The results of this study indicate that glutamine supple­mentation has no positive effect on muscle injury markers after a resistance training session.

To perform an exploratory characterization of repeated sprint sequences (RSS) and repeated acceleration sequences (RAS) in top level soccer referees. 7 field and 7 assistant referees were monitored during 2007 America''s Soccer Cup with GPS technology. Sprints of >18 km·h-1 and accelerations of >1.5 m·s-2 were considered as high intensity activities. RSS and RAS were defined as a minimum of 3 consecutive bouts interspersed with a maximum of 45 s. Field and assistant referees performed substantially more accelerations than sprints. Neither field nor assistant referees recorded any RSS. In contrast, total distance performing RAS amounted to ~37% and ~20% of the total distance covered by accelerations during the entire match for field and assistant referees, respectively. Only field referees exhibited fatigue-related reductions in RAS characteristics between halves. The results of the present study would appear to support the appropriateness of a repeated acceleration ability (RAA) concept, instead of the repeated sprint ability (RSA) concept, in soccer referees. Further studies should assess RAS in referees and athletes of different team sports for designing better training exercises and physiological testing.

Shoulder pain is one of the most common problems in ages older than 60 years of age. Rotator cuff pathology is the most common etiology of shoulder pain. Most of rotator cuff pathologies are treated conservatively in old ages and exercise therapy is not an accepted intervention for management of rotator cuff tear yet. The case was a man of 53 years age with shoulder pain who had total tear of supraspinatus tendon and biceps tendinitis in the right shoulder. He had regularly gone swimming, mountain climbing and running in the last 10 years. The case was managed by exercise therapy for 3 months and physical modalities for 20 sessions. Shoulder pain and his function and right shoulder range of motion increased after 3 months. Para clinical findings did not change after treatment, though. The improvements continued 15 months after the beginning of the treatment. Exercise therapy was very effective for improving pain and function in total tear of supraspinatus tendon and tendinitis of biceps.