Non-athletic Individuals Research Articles

Possible criteria for obesity based on insulin resistance in Japanese college athletes

The purpose of this study was to search for possible criteria for obesity in Japanese college student athletes by examining insulin resistance. The subjects were 219 male college students (mean age 20.4 ± 1.3 years), including 119 athletes who belonged to a university sports team and 100 non-athletic individuals who did not. Fasting blood glucose, hemoglobin A1c (HbA1c), fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) levels were examined in relationship to body mass index (BMI) and waist circumference (WC). Although none of the subjects had diabetes mellitus, 15 (5 athletes (4.2%) and 10 non-athletes (10.0%)) had insulin resistance with HOMA-IR ≥2.5. HOMA-IR was significantly higher in athletes with BMI ≥27.0 kg/m(2) and non-athletes with BMI ≥25.0 kg/m(2) than in subjects with BMI <25.0 kg/m(2). A similar pattern was seen for WC ≥90 cm in athletes and ≥85 cm in non-athletes. Nearly all athletes with increased insulin resistance had BMI ≥27.0 kg/m(2) and WC ≥90 cm. Among non-athletes, nine of the 10 subjects with insulin resistance had BMI ≥25.0 kg/m(2) and WC ≥85 cm. According to these criteria, the sensitivity and specificity were nearly 100% and 93% for athletes, and 90% and 70% for non-athletes, respectively. Japanese college athletes may be at risk for increased insulin resistance when BMI exceeds 27.0 kg/m(2) and WC exceeds 90 cm.

Asthma in elite athletes

Asthma is frequently found among elite athletes performing endurance sports such as swimming, rowing and cross-country skiing. Although these athletes often report symptoms while exercising, they seldom have symptoms at rest. Moreover, compared with nonathletic asthmatic individuals, elite athletes have been shown to have a different distribution of airway inflammation and unequal response to bronchial provocative test. Elite athletes display signs of exercise-induced symptoms, for example, nonasthmatic inspiratory wheeze, vocal cord dysfunction and cardiac arrhythmias, which could limit their physical capacity. Elite athletes should undergo comprehensive assessment to confirm an asthma diagnosis and determine its degree of severity. Treatment should be as for any other asthmatic individual, including the use of β2-agonist, inhaled steroid as well as leukotriene-antagonist. It should, however, be noted that daily use of β-agonists could expose elite athletes to the risk of developing tolerance towards these drugs. Use of β2-agonist should be replaced with daily inhaled corticosteroid treatment, the most important treatment of exercise-induced asthma. All physicians treating asthma should be aware of the doping aspects. Systemic β2-agonist intake is strictly prohibited, whereas inhaled treatment is allowed in therapeutic doses when asthma is documented and dispensation has been granted when needed.

One year cardiac follow up of young world cup football team compared to nonathletes

Sudden cardiac death among professional young athletes has become a significant concern mainly attributed to structural heart changes and ECG abnormalities. We aimed primarily to compare echocardiographic and electrocardiographic changes in young professional athletes versus a control group of sedentary lifestyled nonathletic individuals of the same age group. Secondly, we aimed to follow up echocardiographic and electrocardiographic changes in young professional athletes after one year. We conducted the study from May 2008 to May 2009 by clinical examination, transthoraxic echocardiography and 12 lead ECG. Our study group was the national football team candidates for the youth world cup occurring in Cairo 2009. This study group was compared to a control group of randomly picked nonathletic third year medical students after exclusion of anyone with a known medical illness. The study group was classified into Athletes I representing athletes at the beginning of the study and Athletes II representing athletes after one year follow up. The Study group comprised 34 males, mean age 18.82 ± 1.56 years while the Control group comprised 28 males, age mean 19.64 ± 2.31 years. There was not a significant difference between the two groups regarding number, age, height or weight ( P > 0.05). Clinical parameters showed significantly lower Systolic Blood Pressure SBP (athletes 117.79 ± 6.536, control 126.43 ± 17.043, P = 0.008) and Heart Rate HR (athletes 68.88 ± 5.044, control 77.43 ± 6.033, P = 0.001). ECG parameters showed a significantly longer RR interval (athletes 0.88 ± 0.065, control 0.76 ± 0.078, P = 0.001), while Corrected QTc interval was not significantly different (athletes 0.41 ± 0.029, control 0.42 ± 0.022, P > 0.05). Echo parameters showed a significant increase in Ejection fraction EF (athletes 60.94 ± 3.084 vs control 54.14 ± 13.063, P = 0.005) and Left atrial dimension LA (athletes 3.28 ± 0.392 vs control 2.58 ± 1.321, P = 0.005). On the other hand Septal wall in diastole SWD, Right ventricle dimension RV, Left ventricular end systolic dimension LVESD, Left Ventricular End Diastolic Dimension LVEDD, Aortic Root AO, and Posterior wall in diastole PWD were not significantly different ( P > 0.05). QTc became significantly longer (athletes 0.43 ± 0.028 vs control 0.42 ± 0.022, P = 0.05). SWD was significantly thicker (athletes 1.21 ± 0.23 vs control 1.07 ± 0.17, P = 0.04). SBP, HR remained significantly lower and RR, EF, LA remained significantly greater ( P < 0.05), while RV, LVESD, LVEDD, AO, PWD remained not significantly different both at the beginning and also after 1 year ( P > 0.05). ECG parameters showed a significant increase in QTc (0.41 ± 0.029 vs 0.43 ± 0.028, P = 0.005) and RR interval (0.81 ± 0.167 vs 0.88 ± 0.065, P = 0.046). Echo parameters showed a significant increase in SWD (1.21 ± 0.232 vs 0.93 ± 0.124, P < 0.001), LA (3.62 ± 0.423 vs 3.28 ± 0.392, P = 0.001), RV (2.37 ± 0.565 vs 2.09 ± 0.234, P = 0.011), PWD (1.00 ± 0.200 vs 0.90 ± 0.200, P = 0.008), and a significant decrease in LVESD (3.19 ± 0.679 vs 3.48 ± 0.190, P = 0.016). Other parameters were not statistically significant ( P > 0.05). Professional football playing in young males results in significant changes compared to their control of sedentary nonathletic medical students of similar age. Clinical parameters showed a significant decrease in systolic blood pressure SBP and heart rate HR, ECG parameters showed significant increase in RR interval and QTc interval, and Echocardiographic parameters showed a significant increase in Left atrium diameter LA, Septal wall in diastole SWD, and ejection fraction EF. One year of professional football playing in young males causes a continuing significant increase in ECG parameters QTc, RR interval, and echocardiographic parameters SWD, LA, Right ventricle dimension RV, Posterior wall in diastole PWD and decrease in Left ventricular end systolic diameter LVESD compared to themselves one year earlier. The international concern of Sudden cardiac death among professional young athletes may be attributed to Structural heart changes and ECG abnormalities acquired with professional training.

Is there an interaction between BDKRB2−9/+9 and GNB3 C825T polymorphisms and elite athletic performance?

The -9 deletion allele in the BDKRB2 -9/+9 polymorphism was associated previously with improved endurance performance. We compared the frequency distribution of the BDKRB2 -9/+9 (rs5810761) polymorphism between athletes (n=155) of sports with different demands (endurance runners; n=74 vs sprinters; n=81) as well as between athletes of different competitive levels (elite level; n=46 vs national level; n=109). These results were compared with those of 240 non-athletic healthy individuals. We also tested the influence of the interaction between the BDKRB2 -9/+9 and the GNB3 C825T (rs5443) genotypes in relation to endurance performance. Genotype distribution and allele frequencies were found to be similar in the endurance athlete, sprinter, and control groups (P=0.83 for genotype distribution and P=0.9 for allele frequencies). Similarly, no statistical differences were found between the subgroups of elite-level endurance athletes and national-level endurance athletes, or between elite-level and national-level sprinters (P>0.09 for all comparisons). There was no interaction between BDKRB2 -9/+9 and GNB3 C825T polymorphisms in relation to endurance performance (P=0.16 for interaction effect). In conclusion, the BDKRB2 +9/-9 polymorphism is not associated with endurance performance, at least among Israeli athletes, and the GNB3TT+BDKRB2 -9/-9 "optimal genotype" is not associated with endurance performance.

113 Cardiocascular screening for sinister cardiac disorders in non-athletic young individuals using a mobile cardiac screening unit

<h3>Objectives</h3> The vast majority of sudden cardiac deaths (SCD) in young individuals occur in the absence of antecedent symptoms. Most deaths are due to hereditary or congenital cardiac abnormalities which can be diagnosed during life and therapeutic interventions are available to minimise the risk of SCD. In most Western countries screening of competitive athletes is supported by numerous sporting governing bodies. However, in the non-athletic population screening is confined only to those individuals with cardiovascular symptoms in the context of a family history of premature cardiac disease. Based on this strategy, most non-athletic individuals at risk of SCD would not be identified. In this study we assessed the impact of screening on the health service. <h3>Methods</h3> Over a 3-month period 2671 subjects (mean age 18.8 years; range 14–35 years) were screened with a health questionnaire (HQ), and 12-lead electrocardiography (ECG). Screening was performed using a mobile trailer equipped with ECG and echocardiography machines and manned by cardiac physiologists and a cardiologist. The HQ related to symptoms suggestive of cardiovascular disease and a family history of premature SCD. ECGs were analysed by skilled cardiologists in accordance with the ESC sports cardiology consensus. Individuals with abnormalities on the HQ and/or ECG were investigated further with echocardiography performed on site. Individuals warranting further investigation even after this were referred for 24 h Holter monitoring and exercise stress testing. <h3>Results</h3> Of the total 2671 individuals screened, 2415 (90.4%) had an entirely normal ECG with the remaining 256 (9.6%) requiring on site echocardiography. A further 163 individuals (6.1%) were reassured following echocardiography. Thus a total of 96.5% of all individuals screened were able to leave the mobile cardiac screening unit reassured that no cardiac disorder could be identified in one visit. Only 93 individuals (3.5%) required further investigation after ECG and echocardiography. Preliminary screening identified 16 individuals (0.59%) with cardiac disorders which could prove potentially fatal in five individuals (0.19%) (Brugada ECG pattern: n=2; Wolff-Parkinson-White: n=1; hypertrophic cardiomyopathy: n=1; right ventricular outflow tract ventricular tachycardia (RVOT-VT): n=1). <h3>Conclusions</h3> Extrapolation of this data suggests large scale screening of non-athletic individuals (even in an expert setting) would be associated with a significant number of individuals (3.5%) requiring further investigation even after ECG and echocardiography. However, a huge proportion of individuals screened (96.5%) can be reassured in one visit. This is of particular relevance when considering that these individuals subsequently do not require primary and/or secondary care review.

114 The prevalence of ECG abnormalities in young non-athletic individuals raises concerns regarding implementation of a nationwide screening program:

<h3>Objectives</h3> Pre-participation screening of competitive athletes, combining 12-lead ECG with a health questionnaire and physical examination, has been demonstrated to reduce the incidence of sudden cardiac death (SCD) over a long term follow up period. Paradoxically, the vast majority of SCD occur in the non-athletic population and in the absence of antecedent symptoms. In the UK, screening for sinister cardiac disorders is confined only to those individuals with symptoms, or in the context of a family history of premature cardiac disease. In this study we analysed the prevalence of ECG abnormalities in young non-athletic individuals. <h3>Methods</h3> Between April 2006 and November 2009, 2619 subjects (mean age 18.3 years; range 14–35; 80% male) were investigated with a health questionnaire and 12-lead ECG. The questionnaire related to symptoms suggestive of cardiovascular disease and a family history of premature cardiovascular disease and/or SCD. The 12-lead ECGs were analysed for specific abnormalities as described in the European Society of Cardiology sports cardiology consensus. Specific criteria for an abnormal ECG analysed include P wave abnormalities suggesting left or right atrial enlargement; QRS abnormalities suggesting left ventricular hypertrophy, interventricular conduction delay and frontal plane axis deviation; and ST segment depression and T wave flattening or inversion. <h3>Results</h3> Of the 2619 individuals investigated a total of 505 (19.3%) individuals demonstrated one or more abnormalities on the 12-lead ECG. The abnormal findings are summarised in the table below: <h3>Conclusions</h3> These results demonstrate that there is a high prevalence of ECG abnormalities when applying the ESC sports cardiology consensus criteria to young non-athletic individuals. Many of these abnormalities are non-specific in isolation and warrant further investigations to be carried out. This has significant implications on the feasibility and cost-effectiveness of a national cardiovascular screening programme for sinister cardiac disease.

Canadian Society for Exercise Physiology position stand: The use of instability to train the core in athletic and nonathletic conditioning

The use of instability devices and exercises to train the core musculature is an essential feature of many training centres and programs. It was the intent of this position stand to provide recommendations regarding the role of instability in resistance training programs designed to train the core musculature. The core is defined as the axial skeleton and all soft tissues with a proximal attachment originating on the axial skeleton, regardless of whether the soft tissue terminates on the axial or appendicular skeleton. Core stability can be achieved with a combination of muscle activation and intra-abdominal pressure. Abdominal bracing has been shown to be more effective than abdominal hollowing in optimizing spinal stability. When similar exercises are performed, core and limb muscle activation are reported to be higher under unstable conditions than under stable conditions. However, core muscle activation that is similar to or higher than that achieved in unstable conditions can also be achieved with ground-based free-weight exercises, such as Olympic lifts, squats, and dead lifts. Since the addition of unstable bases to resistance exercises can decrease force, power, velocity, and range of motion, they are not recommended as the primary training mode for athletic conditioning. However, the high muscle activation with the use of lower loads associated with instability resistance training suggests they can play an important role within a periodized training schedule, in rehabilitation programs, and for nonathletic individuals who prefer not to use ground-based free weights to achieve musculoskeletal health benefits.

Espondilólise e espondilolistese em ginastas jovens

OBJECTIVE: To determine the incidence of spondylolysis and spondylolisthesis in young, female gymnasts, and to correlate these with lumbar pain, history of trauma and training load. METHOD: A total of 18 would-be Olympic gymnasts, aged 8-17, with an average age of 11.3, were voluntarily evaluated. The Gymnasts were asked to complete a questionnaire about their sports activities, and were submitted to a clinical examination and lumbar spine radiography. RESULTS: The radiographies were analyzed by experienced specialists in surgery of the vertebral column, who found a 5.56% incidence of spondylolysis and no cases of spondylolisthesis. CONCLUSION: The incidence of radiographic alterations identified remained close to those reported in the literature for non-athletic individuals, and the lumbalgia indicated by the athletes showed no direct relation with spondylolysis and spondylolisthesis.

SPONDYLOLYSIS AND SPONDYLOLISTHESIS IN YOUNG GYMNASTS

Objective: To determine the incidence of spondylolysis and spondylolisthesis among female gymnasts, and to correlate these with lumbar pain, history of trauma and training load. Method: Eighteen competitive-level Olympic-style gymnasts aged 8-17 years, with an average age of 11.3 years, were evaluated on a voluntary basis. The gymnasts answered a questionnaire about their sports activities and underwent a clinical examination and lumbar spine radiography. Results: The radiographs were analyzed by orthopedists specializing in surgery of the vertebral column. The prevalence of spondylolysis was 5.56%, while no cases of spondylolisthesis were found. Conclusion: The incidence of the radiographic abnormalities identified was similar to what has been reported in the literature for non-athletic individuals, and the lumbalgia reported by these athletes did not show any direct relationship with spondylolysis and spondylolisthesis.

Interaction between SNPs in the NRF2 gene and elite endurance performance

Nuclear respiratory factor 2 (NRF2), a member of the Cap-N-Collar family of transcription factors, plays an important role in the mitochondrial biogenesis, and variants of NRF2 gene have been associated with endurance performance. The aims of the present study were 1) to compare NRF2 A/C (rs12594956) and NRF2 C/T (rs8031031) genotype and allele frequencies between athletes of sports with different demands (endurance vs. sprinters) as well as between competitive levels (elite level vs. national level) and 2) to analyze the interaction of these two polymorphisms and its influence on the level of endurance performance. One hundred and fifty-five track and field athletes (74 endurance athletes and 81 sprinters) and 240 nonathletic healthy individuals participated in this study. Endurance athletes presented a higher frequency of the AA (rs12594956) and CT (rs8031031) genotypes than sprinters and the control group, as well as higher A and T alleles, respectively. These differences did not appear between the sprinters and control subjects. The odds ratio for harboring the "optimal genotype" (NRF2 AA+ NRF2 CT) was 4.53 (95% confidence interval 1.23-16.6) in the whole cohort of endurance athletes and 6.55 (95% confidence interval 1.12-38.25) in elite-level endurance athletes, compared with control subjects and both levels of sprinters. In conclusion, our data indicate that the NRF2 A/C and NRF2 C/T single nucleotide polymorphisms (SNPs) are associated, separately and in combination, with elite endurance athletes, which supports the notion that these specific gene variants might belong to a growing group of SNPs that are associated with endurance performance.

Heavy-intensity aerobic exercise affects the isokinetic torque and functional but not conventional hamstrings:quadriceps ratios

Running exercises are frequently related to muscular injuries, which may be a result of muscular imbalance. The present study aimed to verify the effects of heavy-intensity continuous running exercise on the functional and conventional hamstrings:quadriceps ratios, and also in the knee flexors and extensors EMG activity in active non-athletic individuals. Sixteen active males performed maximal isokinetic concentric and eccentric knee flexions and extensions at 60° s −1 and 180° s −1. In another session, the same procedure was conducted after a continuous running exercise at 95% onset of blood lactate accumulation. Torque and electromyographic ratios were calculated from peak torque and integrated electromyographic activity (knee flexor and extensors). Creatine kinase was measured before and 24 h after running exercise. Eccentric torque (knee flexion and extension) decreased significantly after running only at 180° s −1 ( p < 0.05). No differences were found for the conventional torque ratios ( p > 0.05), however, the functional torque ratios at 180° s −1 decreased significantly after running ( p < 0.05). No effects on the electromyographic activity and electromyographic ratios were found ( p > 0.05). Creatine kinase increased slightly 24 h after running ( p < 0.05). Heavy-intensity continuous running exercise decreased knee flexor and extensor eccentric torque, and functional torque ratios under fast velocities (180° s −1), probably as result of peripheral fatigue.

Differences On Resting Energy Expenditure And Respiratory Quotient After Two Submaximal Exercises In Young Athletes

Physical activity has been recognized as an important factor for maintenance of body mass. Many studies have shown that both acute and chronic exercise produce increases on resting energy expenditure and fat oxidation. Intensity and duration of exercise are essential and have been extensively studied for preventing obesity purposes, but their relationship has not been clearly determined since the exercise required to promote this changes is unlikely to be performed by non-athletic individuals. PURPOSE: To determine the differences on resting energy expenditure and respiratory quotient after two 30-min-treadmill walking, at 60% and at 70% of maximal oxygen uptake, in young race walker athletes. METHODS: Nine male athletes 15 to 20 years of age, from a new talent race walking group, were measured by weight, height, body mass index (BMI) and percentage of body fat (%BF) by anthropometry. Maximal Oxygen uptake (VO2max) was obtained by an exercise stress testing before to perform two 30-min-treadmill exercises, at 60% and at 70% of VO2max, which were randomly accomplished 3 to 5 days apart. Resting energy expenditure (REE) and respiratory quotient (RQ) were measured by indirect calorimetry before and after each submaximal workload. Descriptive statistics and paired t test at a p<0.05 significance level were used. RESULTS: Athletes were 17.8 ± 2.3 years old, had 21.6 ± 1.6 Kg/m2 of BMI, 9.2 ± 2.0 %BF and 60.6 ± 6.4 mL.kg−1.min−1 of VO2max. REE was higher after both workload intensities than before (1490 ± 205 vs 1837 ± 187 Kcal/day and 1437 ± 163 vs 1888 ± 265 Kcal/day, pre and post 60% and 70% of VO2max exercises respectively, p<0.01). No differences were seen between the two 30-min-treadmill walking where the increases represented the 24.4% and 31.3%, respectively. RQ was 13% lower after both exercises than before (0.91 ± 0.08 vs 0.79 ± 0.07 and 0.90 ± 0.10 vs 0.78 ± 0.06 pre and post 60% and 70% intensities respectively, p<0.01). CONCLUSIONS: A short session of aerobic exercise at 60% or 70% of VO2max increases REE in young athletes regardless their different intensities. They showed similar higher fat oxidation after both submaximal workouts. Acknowledgements: This research was supported by CONACyT Government of Mexico, grant 9702009.

Avaliação ultra-sonográfica da articulação do ombro em nadadores de nível competitivo

OBJETIVO: Avaliar o ombro de nadadores em nível competitivo, sintomáticos ou não, e quantificar a incidência de lesões do manguito rotador nesses atletas. MATERIAIS E MÉTODOS: Foram estudados, por meio de exame ultra-sonográfico, ambos os ombros de 11 nadadores de nível competitivo (categoria master), sendo oito homens e três mulheres, com idade variando de 28 a 52 anos, tanto sintomáticos quanto assintomáticos, para determinação de alterações e correlação com quadro clínico. Os exames foram realizados avaliando-se os tendões que compõem o manguito rotador em pelo menos dois planos ortogonais distintos, assim como as estruturas não-tendíneas que fazem parte da articulação do ombro. As alterações tendíneas foram classificadas como tendinose, prováveis roturas intra-substanciais e roturas parciais. As lesões não-tendíneas foram classificadas como presentes ou ausentes. Além do exame, foram consideradas, na análise dos resultados, a presença ou ausência de sintomas e a idade dos pacientes. RESULTADOS: A prevalência geral de indivíduos sintomáticos foi de 63,6% (sete atletas). Neste grupo encontravam-se 75% das bursites e 100% das roturas tendíneas parciais. Entre as alterações tendíneas isoladas, o tendão mais freqüentemente acometido foi o supra-espinal, tendo alteração de seu padrão ecográfico em 36,36%. A tendinose foi o achado mais prevalente, estando presente em pelo menos um dos tendões em 50% dos ombros estudados. A incidência de roturas parciais foi semelhante à observada na população geral, sendo de 13%, estando estas, sempre que presentes, na faixa etária acima de 40 anos. CONCLUSÃO: Nadadores não parecem ter maior incidência de roturas ou degenerações tendíneas quando comparados com indivíduos da população geral. A idade dos indivíduos, sendo estes praticantes ou não de atividades que exijam sobrecarga desta articulação, é o fator com maior determinância em relação às lesões do manguito rotador.

Effects of prolonged running performed at the intensity corresponding to the onset of blood lactate accumulation, on maximum isokinetic strength in active non-athletic individuals

Objective: The objective of this study was to analyze the effects of prolonged continuous running performed at the intensity corresponding to the onset of blood lactate accumulation (OBLA), on the peak torque of the knee extensors, analyzed in relation to different types of contraction and movement velocities in active individuals. Method: Eight men (23.4 ± 2.1 years; 75.8 ± 8.7 kg; 171.1 ± 4.5 cm) participated in this study. First, the subjects performed an incremental test until volitional exhaustion to determine the velocity corresponding to OBLA. Then, the subjects returned to the laboratory on two occasions, separated by at least seven days, to perform five maximal isokinetic contractions of the knee extensors at two angular velocities (60 and 180°.s -1 ) under eccentric and concentric conditions. Eccentric peak torque (EPT) and Concentric peak torque (CPT) were measured at each velocity. One session was performed after a standardized warm-up period (5 min at 50% VO 2 max). The other session was performed after continuous running at OBLA until volitional exhaustion. These sessions were conducted in random order. Results: There was a significant reduction in CPT only at 60°.s -1 (259.0 ± 46.4 and 244.0 ± 41.4 N.m). However, the reduction in EPT was significant at 60°.s -1 (337.3 ± 43.2 and 321.7 ± 60.0 N.m) and 180°.s -1 (346.1 ± 38.0 and 319.7 ± 43.6 N.m). The relative strength losses after the running exercise were significant different between contraction types only at 180°.s -1 . Conclusion: We can conclude that, in active individuals, the reduction in peak torque after prolonged continuous running at OBLA may be dependent on the type of contraction and angular velocity.

Effects of exercise intensity and duration on the excess post-exercise oxygen consumption

Recovery from a bout of exercise is associated with an elevation in metabolism referred to as the excess post-exercise oxygen consumption (EPOC). A number of investigators in the first half of the last century reported prolonged EPOC durations and that the EPOC was a major component of the thermic effect of activity. It was therefore thought that the EPOC was a major contributor to total daily energy expenditure and hence the maintenance of body mass. Investigations conducted over the last two or three decades have improved the experimental protocols used in the pioneering studies and therefore have more accurately characterized the EPOC. Evidence has accumulated to suggest an exponential relationship between exercise intensity and the magnitude of the EPOC for specific exercise durations. Furthermore, work at exercise intensities ≥50 – 60% [Vdot]O2max stimulate a linear increase in EPOC as exercise duration increases. The existence of these relationships with resistance exercise at this stage remains unclear because of the limited number of studies and problems with quantification of work intensity for this type of exercise. Although the more recent studies do not support the extended EPOC durations reported by some of the pioneering investigators, it is now apparent that a prolonged EPOC (3 – 24 h) may result from an appropriate exercise stimulus (submaximal: ≥50 min at ≥70% [Vdot]O2max; supramaximal: ≥6 min at ≥105% [Vdot]O2max). However, even those studies incorporating exercise stimuli resulting in prolonged EPOC durations have identified that the EPOC comprises only 6 – 15% of the net total oxygen cost of the exercise. But this figure may need to be increased when studies utilizing intermittent work bouts are designed to allow the determination of rest interval EPOCs, which should logically contribute to the EPOC determined following the cessation of the last work bout. Notwithstanding the aforementioned, the earlier research optimism regarding an important role for the EPOC in weight loss is generally unfounded. This is further reinforced by acknowledging that the exercise stimuli required to promote a prolonged EPOC are unlikely to be tolerated by non-athletic individuals. The role of exercise in the maintenance of body mass is therefore predominantly mediated via the cumulative effect of the energy expenditure during the actual exercise.

Comparação entre protocolos diretos e indiretos de avaliação da aptidão aeróbia em indivíduos fisicamente ativos

O limiar anaeróbio individual (IAT), o limiar glicêmico individual (IGT), a velocidade associada ao VO2max (Vmax), a velocidade média em corrida de 3.000m (Vm3km) e a velocidade crítica (VC) têm sido utilizados na avaliação aeróbia e prescrição de exercício para atletas-corredores. No entanto, estudos comparando estes parâmetros e sua possível aplicação para indivíduos não atletas ainda não foram realizados. Os objetivos do presente estudo foram comparar e estabelecer as relações entre IAT, IGT, Vmax, Vm3km e VC em indivíduos fisicamente ativos não atletas. Onze indivíduos fisicamente ativos e saudáveis (20,7 ± 1,8 anos; 74,2 ± 14,5kg; 48,9 ± 5,8mlO2.kg.min-1) realizaram randomicamente os seguintes testes de corrida em dias distintos: 1) determinação da Vm3km a partir do desempenho em corrida de 3.000m; 2) desempenho em corrida de 500m e 3) teste incremental em esteira ergométrica para determinação do IAT, IGT, VO2max e Vmax. A VC foi determinada por regressão linear (relação distância-tempo) a partir dos testes de 3km e 500m. Não foram verificadas diferenças entre as velocidades do IAT e IGT (184,8 ± 27,7 e 182,8 ± 27,9m.min-1; P &gt; 0,05), e entre Vmax e Vm3km (211,1 ± 30 e 213,4 ± 32,2m.min-1; P &gt; 0,05). Apesar da alta correlação entre as variáveis estudadas, a VC (199,8 ± 30,4m.min-1) superestimou o IAT e o IGT (P &lt; 0,001). Concluímos que a Vm3km pode ser utilizada como referência de Vmax e que a VC identificada em pista pode ser útil para avaliar a aptidão aeróbia e identificar domínios de intensidade de exercício para indivíduos jovens fisicamente ativos, mas não como referência de limiar anaeróbio.

Blood Lipid Peroxides and Muscle Damage Increased following Intensive Resistance Training of Female Weightlifters

The aim of this study was to examine changes in muscle cell injury and antioxidant capacity of weightlifters following a 1-week intensive resistance-training regimen. Thirty-six female subjects participated in this study, and their ages ranged from 18 to 25 years. The sample group included 19 elite weightlifters with more than 3 years of weightlifting training experience, while the control group comprised 17 non-athletic individuals. Compared with non-athletes, weightlifters had significantly lower glutathione peroxidase activity and plasma vitamin C concentrations. Weightlifters also had significantly higher malondialdehyde + 4-hydroxy 2-(E)-nonenal (MDA+4-HNE) and thiobarbituric acid-reactive substance (TBARS) levels and creatine kinase (CK) activity. For weightlifters, the plasma vitamin E level and the activity of superoxide dismutase (SOD) decreased, and CK activity increased significantly (P < 0.05) after a 1-week intensive resistance-training regimen. Both the TBARS levels and CK activity returned to values of pre-intensive training after a 2-day rest. The MDA+4-HNE level strongly correlated with CK activity in weightlifters (P < 0.05). In conclusion, both long-term exercise training and 1 week of intensive resistance training resulted in increased oxidative stress and cell injury in female weightlifters. Furthermore, proper rest after intensive training was found to be important for recovery.

Infección fúngica en pies de jugadores de fútbol y en no atletas

This study was conducted to evaluate the occurrence of mycoses affecting the feet of soccer players and to compare this results with those in non-athlete individuals of the same age and sex. Initial evaluation consisted of a dermatological examination of the foot in 22 Chinese athletes, 83 Brazilian athletes and 24 Brazilian non-athletes. Scales of plantar skin, interdigital and subungual areas of the foot were collected for mycological examination (direct and culture). Nail clippings were obtained for histopathologic analysis. Tinea pedis was diagnosed more frequently among the non-athlete individuals. None of the Chinese athletes had tinea pedis alone. However, in this group onychomycosis was frequently higher when compared to the other groups. The fungal microbiota comprised Trichophyton rubrum (40%), Trichophyton mentagrophytes (36.4%) and Candida spp (20%). Candida spp was isolated only from Brazilian athletes. Results obtained with KOH wet mounts agreed with the results obtained in culture and with histopathologic examinations (50.5% vs 40.9%). The frequency of tinea pedis among soccer players was lower than the other groups in this study, possibly due to health education and professional feet care.

Effects of exercise on lipid metabolism and musculoskeletal fitness in female athletes.

This study investigated the effects of intense training on lipid metabolism, bone metabolism and bone mineral density (BMD) in female athletes. Sixty-six female subjects participated in this study, age ranging from 18 to 55 years. The sample group included thirty-six athletic subjects and the control group comprised thirty non-athletic individuals. Five athletes competed with national level (5/36) and nine non-athletic subjects (9/30) were postmenopausal women. The assessment items included body composition, radius BMD, calcaneus BMD, lung function, muscular endurance, renal and liver function, bone marker assay and hormone status. All data were analysed, using SPSS 10.0 software, and were presented as mean rank statistical difference, using the Kurskal-Wallis (K-W) test. After that the non-parameter statistics were used. Either K value or P value below 0.05 was considered significant. Urine deoxypyridinoline/creatinine (Dpd/Cre) levels increased significantly (5.93+/-2.31 vs 6.85+/-1.43, K<0.01), sit-reach (29.30+/-9.48 cm vs 41.31+/-9.43 cm, K<0.001, P<0.001), 1 minute sit-ups with bended knees (1 min sit-ups) (17.60+/-9.34 count vs 30.00+/-10.38 count, K<0.001, P<0.001), and vertical jump (25.27+/-6.63 cm vs 34.69+/-7.99 cm, K<0.001, P<0.001) improved significantly in the athletes group. The athletes group also had a significantly increased level of estriol (E(3)) (0.14+/-0.13 pg/mL vs 0.07+/-0.04 pg/mL, K<0.01, P<0.01), radius BMD (1.37+/-0.49 gm/cm(2) vs 1.19+/-0.40 gm/cm(2), K<0.05) and calcaneus BMD (0.57+/-0.17 gm/cm(2) vs -0.20+/-0.17 gm/cm(2), K<0.01, P<0.05) compared with those of the controls. The high density lipoprotein (HDL) (65.00+/-14.02 mg/dL vs 52.26+/-4.84 mg/dL, K<0.05, P<0.05) was significantly lower in postmenopausal inactive athletes (5/36) than premenopausal active athletes (31/36). On the other hand, low-density lipoprotein (LDL) (98.35+/-23.84 mg/dL vs 131.00+/-21.63 mg/dL, K<0.05, P<0.01), cholesterol (CHO) (164.03+/-27.01 mg/dL vs 193.00+/-23.48 mg/dL, K<0.05, P<0.05), triglyceride (TG) (63.00+/-26.39 mg/dL vs 147.00+/- 87.21 mg/dL, K<0.01), body fat % (BF%) (28.16+/-4.90% vs 34.84+/-4.44%, K<0.05, P<0.001) and body mass index (BMI) (21.98+/-2.98 kg/m(2) vs 26.42+/-5.01 kg/m(2), K<0.05, P<0.001) were significantly higher in postmenopausal inactive athletes (5/36) than premenopausal active athletes (31/36). TG (90.22+/-39.82 mg/dL vs 147.00+/-87.21 mg/dL), CHO (186.44+/-24.90 mg/dL vs 193.00+/-23.48 mg/dL) were higher, but the HDL was significantly lower (62.18+/-10.68 mg/dL vs 52.26+/-4.84 mg/dL, P<0.05) in postmenopausal athletes (5/36) group than in postmenopausal control group (9/30). Postmenopausal athletes (5/36) who no longer took competing exercises had reduced levels of physical activity, faced increased risk of cardiovascular disease compared to active athletes (31/36) and the postmenopausal controls (9/30). We may thus concluded that long term exercise effectively improves musculoskeletal fitness and prevents BMD loss in female athletes.

Avaliação isocinética em atletas paraolímpicos

O equilíbrio dos parâmetros de força muscular nas articulações é de grande relevância, tanto no aspecto clínico como para o desempenho atlético. Informações sobre os valores desses parâmetros em atletas olímpicos e principalmente nos paraolímpicos são raras. Neste trabalho apresentamos os resultados da avaliação muscular isocinética (Cybex 6000) realizada na equipe brasileira que participou dos Jogos Paraolímpicos de Sidney 2000. Foram avaliados os músculos flexores e extensores dos joelhos de 11 jogadores de futebol (paralisia cerebral, idade 24,6 ± 4,8 anos; peso 67 ± 5,5kg; altura 177,7 ± 3,8cm) e 12 de basquetebol (deficientes mentais, idade 24,7 ± 4,4 anos; peso 76,6 ± 13,4kg; altura 184,4 ± 10cm), e os músculos rotadores internos e rotadores externos de ombros de seis judocas (deficientes visuais, idade 29,8 ± 5,6 anos; peso 87 ± 21,6kg; altura 171,5 ± 6,9cm). Os jogadores de futebol apresentaram relação de equilíbrio muscular entre flexores e extensores de joelhos dentro dos parâmetros de normalidade apesar da fraqueza muscular imposta pela paralisia cerebral. Nos judocas o equilíbrio muscular entre rotadores externos e rotadores internos mostrou-se dentro dos limites de normalidade. A principal característica dos jogadores de basquetebol foi o valor de pico de torque próximo do esperado para indivíduos hígidos não atletas. Os valores numéricos estão apresentados no texto para serem usados como referência para profissionais da área.