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T Horstmann

Publications and source records attributed to T Horstmann.

30 records · Page 2Linked to original sources
PubMed1998

Predicting competition performance in long-distance running by means of a treadmill test.

PURPOSE: The purpose of this study was to examine the power of 16 parameters beside the individual anaerobic threshold (IAT) in predicting performance in various competition distances. METHODS: This study examined 427 competitive runners to test the prediction probability of the IAT and other parameters for various running distances. All runners (339 men, 88 women; ages, 32.5 +/- 10.14 yr; training, 7.1 +/- 5.53 yr; training distance, 77.9 +/- 35.63 km.wk-1) performed an increment test on the treadmill (starting speed, 6 or 8 km.h-1; increments, 2 km.h-1; increment duration, 3 min to exhaustion). The heart rate (HR) and the lactate concentrations in hemolyzed whole blood were measured at rest and at the end of each exercise level. The IAT was defined as the running speed at a net increase in lactate concentration 1.5 mmol.L-1 above the lactate concentration at LT. RESULTS: Significant correlations (r = 0.88-0.93) with the mean competition speed were found for the competition distances and could be increased using stepwise multiple regression (r = 0.953-0.968) with a set of additional parameters from the training history, anthropometric data, or the performance diagnostics. CONCLUSIONS: The running speed at a defined net lactate increase thus produces an increasing prediction accuracy with increasing distance. A parallel curve of the identity straight lines with the straight lines of regression indicates the independence of at least a second independent performance determining factor.

Adult↗
PubMed1998

Effects of intensive endurance exercise on DNA damage in leucocytes.

OBJECTIVE: It has been shown that highly intensive anaerobic exercise induces DNA damage in leucocytes (LEU). The present study was designed to investigate whether intensive endurance exercise is capable of inducing comparable effects. EXPERIMENTAL DESIGN: A prospective study. PARTICIPANTS: Twelve men (aged 27.3 +/- 4.1 years) who undertook a regular training of different extent (running volume 45 +/- 25 km.week-1) volunteered in the study. INTERVENTIONS: The subjects competed in a half marathon (HM) of 21.1 km, 93.0 +/- 10.4 min. MEASUREMENTS: Blood was taken at rest, 1 and 24 hrs after HM for determination of creatine kinase, neutrophil (PMN), lymphocyte and monocyte counts. DNA damage in LEU at rest and 24 hrs after HM was quantified using the single cell gel-electrophoresis (SCG) assay. RESULTS: PMN increased from 2.81 +/- 0.69 to 13.13 +/- 2.91 1 hrs after HM (p < 0.01) and returned to 3.26 +/- 0.47 10(9) cells.l-1 by 24 hr recovery. DNA migration (image length, IL) reflecting the extent of DNA damage was elevated significantly in 10 of 12 subjects one day after HM. IL rose from 32.7 +/- 2.2 to 40.7 +/- 3.9 microns (p < 0.01). Correlation analysis revealed a relationship between DNA migration 24 hrs after HM and PMN count 1 hr post-exercise (r = 0.67, p < 0.05). CONCLUSIONS: The results confirm the hypothesis that DNA damage in LEU occurs after intensive endurance exercise. We suppose our observation of exercise-induced DNA damage in LEU is affected by reactive oxygen species which are released from PMN. It is quite unclear whether DNA damage in LEU is causal involved in exercise-induced modifications of the immune system.

Adult↗
PubMed1997

Effects of contract-relax stretching training on muscle performance in athletes.

The effects of an 8-week unilateral contract-relax (CR) stretching training program (passive stretch after isometric contraction) on muscular performance were investigated in a group of 16 athletes. The flexibility, maximum torque and angular position as well as contraction work in movements of the knee joint were determined before training and after 4 and 8 weeks of training. The torque measurements were performed under isokinetic conditions, eccentrically at angular velocities of 60 degrees x s(-1) and 120 degrees x s(-1), isometrically at five different joint positions, and concentrically at angular velocities of 60, 120, 180 and 240 degrees x s(-1) using an isokinetic dynamometer. A surface electromyogram (EMG) of the thigh muscles (quadriceps and hamstrings) was recorded simultaneously. As compared to untrained control limbs, significant improvements in active and passive flexibility (up to 6.3 degrees in range of motion), maximum torque (up to 21.6%) and work (up to 12.9%) were observed, and these were especially pronounced under eccentric load conditions. A comparison between integrated EMG recordings during eccentric and concentric loads, as well as the interpretation of the training-induced changes in the EMG, suggest that muscular activity under eccentric loads may be impaired by mental processes.

Adaptation, Physiological↗
PubMed1994

Normal values of isokinetic maximum strength, the strength/velocity curve, and the angle at peak torque of all degrees of freedom in the shoulder.

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.

Adult↗
PubMed1994

Reproducibility of isokinetic peak torque and angle at peak torque in the shoulder joint.

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.

Adult↗
PubMed1994

The cardiocirculatory reaction to isokinetic exercises in dependence on the form of exercise and age.

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.

Adult↗
PubMed1994

Isokinetic force-velocity curves in patients following implantation of an individual total hip prosthesis.

There are only a few studies which could support conclusions concerning the strength of the muscles surrounding the hip joint and especially concerning the strength relationships following implantation of endoprostheses. The aim of this study was to examine the post-operative course of strength deficits in this musculature compared to clinical parameters. Fifty-eight patients between 30 and 67 years of age, in whom individual total hip prostheses were implanted, were clinically examined prior, 9 weeks and 6 months after surgery. Moreover, the maximum isometric strengths of abductors, flexors, and rotator muscles as well as maximum isokinetic strengths of the extensors and flexor musculature at 60 degrees/s and 120 degrees/s were measured. The flexor and extensor musculature already showed a clear increase in maximum strength after 9 weeks and 6 months. By contrast, the isometric strengths of the rotators increased only slightly, the abductor strength decreased after 9 weeks to below the preoperative baseline level and attained this level again only after 6 months. The clinical parameters Trendelenburg sign, limping, and walking capacity were clearly improved after 6 months, but no correlation to the abductor strength could be demonstrated. It is concluded that limp-free gait can be attained even without maximum strength increase in the abductors, which are important for fluid gait, at least for short distances. The importance of regular training of the rotator and abductor musculature in coxarthrosis is emphasized to delay limitation of movement and decreased strength in the sense of a capsule pattern.

Adult↗
PubMed1989

The long-term involution of physiological cardiomegaly and cardiac hypertrophy.

The long-term involution of physiological cardiomegaly and cardiac hypertrophy. Med. Sci. Sports Exerc., Vol. 21, No. 3, pp. 244-249, 1989. Forty-five former athletes in endurance disciplines, primarily Olympic medalists and World Cup, European Cup, and German champions, for whom results of an exercise ECG and radiological heart volume measurement were available from their active competitive phase, were examined. The study protocol included clinical examination, laboratory controls, resting and exercise ECG, determination of cardiac volume, and one- and two-dimensional echocardiographic examination. Of the 45 former athletes contacted, 38 appeared for examination. Of these, four presented with heart disease (two with infarction, one with aortic stenosis, and one with arrhythmia). The remaining 34 were divided into groups of still active (more than 300 kcal.wk-1) and inactive (less than 300 kcal.wk-1) athletes. The interval between the first and second examination averaged 23 yr. The active former athletes showed a weight increase of 5.2% (P less than 0.01) and a reduction of 14% in ergometric performance (P less than 0.02). The inactive group had a marked weight increase of 17.4% (P less than 0.001); the ergometric performance was lowered by 20% (P less than 0.001). The absolute heart size had decreased in the active group by 6.1% (NS) and the relative heart size by 10.7% (P less than 0.005); the corresponding values in the inactive group were 4.5% (NS) and 18% (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗
PubMed1983

[Juvenile diabetes mellitus with optic atrophy and labyrinthine deafness. An autosomal-recessive inherited syndrome].

A now 12 year old boy developed diabetes mellitus when he was 7 years old. From 9 years on he developed progressive optic atrophy and deafness. Type I diabetes mellitus, together with progressive optic atrophy and several other symptoms like deafness, diabetes insipidus and ectasy of urinary tract are known for more than 40 years as autosomal-recessively inherited conditions. Therefore, in case of diabetes mellitus combined with optic atrophy it is necessary to search for further symptoms, developing during the course of the disease. Genetic counselling to the families is mandatory.

Child↗
PubMedDate not supplied

[Strength of muscles surrounding the hip joint and gait in patients following implantation of a cementless hip endoprosthesis].

There are only a few studies which could support conclusions concerning the strength of the muscles surrounding the hip joint and especially concerning the strength relationships following implantation of endoprotheses. The aim of this study was to examine the pre- and postoperative course of strength deficits in this musculature compared to clinical parameters and the uninvolved side. Fifty-eight patients between 30 and 67 years of age, in whom individual total hip protheses were implanted were clinically examined prior, 9 weeks and 6 months after surgery. Moreover, the maximum isometric strength of abductors, flexors, and rotator muscles as well as maximum isokinetic strength of the extensors and flexor musculature at 60% and 120%/s were measured. The flexor and extensor musculature already showed a clear increase in maximum strength after 9 weeks and 6 months (90-124%). By contrast, the isometric strengths of the rotators increased only slightly, the abductor strength decreased after 6 weeks to below the preoperative baseline level and attained this level again only after 6 months. The clinical parameters Trendelenburg sign, limping and walking capacity were clearly improved after 6 months, but no correlation to the abductor strength could be demonstrated. It is concluded that limp-free gait can be attained even without maximum strength increase in the abductors, which are important for fluid gait, at least for short distances. The importance of regular training of the rotator and abductor musculature in coxarthrosis is emphasized to delay limitation of movement and decreased strength in the sense of capsule pattern.

Adult↗