Anaerobic threshold as a basic criterion of training recommendation can be estimated by various parameters. The purpose of this study was to investigate the relationship and the reproducibility of ventilatory, lactate-derived and catecholamine thresholds of an incremental treadmill exercise. Therefore, 11 male subjects underwent two incremental treadmill tests within 7 days. The lactate threshold (LT) was determined at the lowest value of the lactate-equivalent (ratio lactate/performance). The individual anaerobic threshold (IAT) was calculated at LT+1.5 mmol/L lactate. The ventilatory thresholds, using mass-spectrometry, were defined by the V-slope method (AT) and at the deflection point of end-tidal CO2 (ET-CO2) concentration (RCP). The thresholds of epinephrine (TE) and norepinephrine (TNE) were calculated in the manner of LT. The running velocities were highly reproducible at LT (test-retest correlation coefficient r=0.90), IAT (r=0.97), AT (r=0.88) and RCP (r=0.95). By contrast TE (r=0.49) and TNE (r=0.46) showed a poor reproducibility. TE and TNE occurred 5-11% below LT and AT with a low correlation to LT and AT. LT was found 4% below AT, both were correlated with r=0.70 (p<0.01, test 1) and r=0.95 (p<0.01, test 2). IAT occurred 7-8% above RCP, in both tests a close correlation was found between IAT and RCP of r=0.97 (p<0.01). In summary, the ventilatory and lactate-derived thresholds show a high and similar reproducibility, but the catecholamine threshold does not. In the present exercise protocol, there are systematic differences between the lactate-derived and ventilatory thresholds, in spite of a close relationship, and these must be taken into account in recommendations derived for training.

Many acute and chronic complaints in the shoulder joint are due to a reduced active stabilization capacity. Procedures to measure isokinetic strength are used to objectify the muscle deficits and imbalances of various muscle groups. In this study, standard values and reference ranges were determined for peak torque (PT), strength/velocity curve, and range of motion (ROM) at peak torque in the shoulder in 19 untrained women and 32 men. Differentiation was made by the individual degrees of freedom of the shoulder joint and the various types of work (concentric, isometric, eccentric). Moreover, the influence of height, body weight, and body mass index on isokinetic maximum strength development was investigated. It was found that it is necessary to distinguish between the various movements and types of work in development of peak torque. A decrease in maximum strength is observed in the sequence extension, adduction/flexion, abduction/internal rotation, external rotation. The maximum strength of men was determined to be higher than that in women. ROM shows a wide fluctuation and does not possess high validity. Height, as well as body weight and body mass index have only slight influence on the isokinetic maximum strength in the shoulder of untrained men and women.

Adequate reliability studies of knee flexion and extension are currently available for isokinetic measurements, but not for the shoulder joint. For this reason, this study examines the variability (%) in the determination of peak torque (PT) and the angle at peak torque (AP) in the test-retest procedure. Differentiation is made between the various types of work (concentric, isometric, eccentric) and the degrees of freedom in the shoulder joint (flexion/extension, abduction/adduction, external rotation/internal rotation). The results show a variability of PT for concentric measurements of 15.0%-19.0% for all degrees of freedom; for flexion/extension and abduction/adduction in isometric and eccentric work, the variability is 17.5%-25.3%. External and internal rotation show generally greater deviation (29.0%-35.3%), except in concentric work. The angle at peak torque can only be reproduced to a limited degree (25.1%-41.1% variability). It is concluded that lower reproducibility can be attained for the shoulder joint compared to the knee joint, depending on the degree of freedom and exercise form tested. It appears meaningful to cite only ranges for the angle at peak torque.

Buffering is a factor which influences performance in short and middle-term endurance by compensating exercise acidosis. The aim of the study was to establish whether respiration parameters are a relative measure of buffering capacity and to study the influence of buffering on specific performance parameters. Three groups (each of ten subjects) with defined degrees of adaptation [untrained (UT), aerobic-trained (AeT) and elite 400-m runners (AnT) with a best time of 48.47 +/- 0.98 s] were examined in an incremental multi-stage test on the treadmill. Breath-by-breath gas analysis was performed using mass spectrometry and computer routines. Serum lactate concentrations were determined at each exercise level until subjective exhaustion. A value for the relative functional buffering capacity (relFB) was calculated using exercise metabolic parameters. Running speed at the lactate threshold was used as the starting point of buffering. The start of respiratory compensation of acidosis (RCP) was taken as the endpoint of buffering. RCP was determined at the point of decrease in end-tidal CO2 content (CO2-ET). RelFB was given in percent of buffering to running speed at RCP. Group AnT attained the same maximum performance data (maximum running speed, maximum rate of O2 consumption) as group AeT. However, these values were attained in group AnT with a significantly higher relFB (AnT: 31.0 +/- 3.2% vs. AeT: 15.7 +/- 3.9%, P < 0.0001), while a higher lactate threshold indicated a greater oxidative capacity in AeT (AeT: 3.07 +/- 0.26 m.s-1 vs. AnT: 2.68 +/- 0.22 m.s-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Although isokinetic training is gaining in importance in prevention and rehabilitation, even for older patients, there is hardly any information available on the extent of cardiocirculatory stress. This study was aimed, therefore, at examining the cardiocirculatory reaction to various isokinetic forms of exercise in dependence on age. Sixty-four subjects between 22 and 60 years of age were assigned to four age groups and the maximum torque measured in concentric and eccentric exercises with various angle accelerations. Moreover, all subjects underwent 1-min concentric and eccentric endurance stress and an isometric test. The cardiocirculatory reaction as reflected in heart rate and blood pressure patterns was determined, as well as the plasma catecholamines adrenaline and noradrenaline measured. The eccentric maximum torque was significantly above the concentric maximum torque; there was a significant inverse relationship to age only in the concentric mode of exercise (r = -0.48; p < 0.01). The cardiocirculatory reaction in endurance stress and isometry, like the behavior of heart rate, blood pressure, and plasma catecholamines, was greatest in concentric exercise, although the maximum strength values were lower, followed by eccentric exercise and isometry. Exercise values such as those attained in maximum ergometric forms of exercise were not reached. It is concluded that no special precautionary measures are required in isokinetic forms of exercise.

Breath-hold divers employ glossopharyngeal insufflation (GI) in order to prevent the lungs from compressing at great depth and to increase intrapulmonary oxygen stores, thus increasing breath-hold time.The presented case study shows the physiological data and dynamic magnetic resonance imaging (dMRI) findings of acute hyperinflation, deliberately induced by GI, in a breath-hold diver and discusses the current state of knowledge regarding the associated hazards of this unique competitive sport.Static and dynamic lung volumes and expiratory flows were within the normal range, with vital capacity and peak expiratory flow being higher than the predicted values. Airway resistance and diffusing capacity of the lung for carbon monoxide were normal. Static compliance was normal and increased five-fold with hyperinflation. dMRI revealed a preserved shape of the thorax and diaphragm with hyperinflation. A herniation of the lung beneath the sternum and enlargement of the costodiaphragmatic angle were additional findings during the GI manoeuvre. After expiration, complete resolution to baseline was demonstrated.Hyperinflation can be physiological and even protective under abnormal physical conditions in the sense of acute adaptation to deep breath-hold diving. Dynamic magnetic resonance imaging is adequate for visualisation of the sequence of the glossopharyngeal insufflation manoeuvre and the complete reversibility of deliberate hyperinflation.

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Hypertrophic non-obstructive cardiomyopathy (HNCM) is one of the most frequent causes of sudden cardiac death in young athletes. Since the clinical findings in HNCM patients may be inconspicuous and the ECG changes found in endurance athletes may be similar to those of HNCM patients, echocardiography, as a non-invasive procedure, seems to take on an important role in differential diagnostics. To prove this hypothesis, conventional echocardiographic parameters were compared in three groups with confirmed diagnosis: Group I: HNCM (n = 9) without sports activity; Group II: HNCM (n = 9) with regular, intensive endurance training (3-5 hours/week). The diagnosis was invasively confirmed in both groups. Group III: healthy subjects (n = 9) with physiological hypertrophy and regular endurance training (3-6 hours/week). In the presence of HNCM, endurance sports activity appears to offset the reduction in the left ventricle and enlargement of the left atrium. The wall thickness of the septum and posterior wall do not differ in the two HNCM groups, but show a significant difference to the healthy athletes. The enddiastolic diameter, the absolute septum and posterior wall thickness and the ratio of septum+posterior wall/enddiastolic diameter can be taken as the most important differential diagnostic criterium in physiological hypertrophy, but not the ratio between septum/posterior wall. It is concluded that conventional echocardiographic examination can be considered a valuable non-invasive method for differentiating HNCM from athlete's heart, even in patients with HNCM who participate in endurance sports. However, a reliable diagnosis may not be possible in individual cases.