Biomedical subjects

H-H Dickhuth

Publications and source records attributed to H-H Dickhuth.

9 recordsLinked to original sources

PubMed2005

[Sports medicine in Germany].

Sports medicine covers many different aspects, ranging from clinical specialties, such as internal medicine, orthopedics or pediatrics to physiology and sports sciences. The requirements for sports medicine evolve mainly from exercise physiology (elite, leisure and health oriented physical activity), orthopedics and traumatology as well as from preventive and rehabilitative issues. In the new German curriculum, sports medicine is defined as a subspecialty. Historically, sports medicine in Germany has a federal structure with a governing body (Deutsche Gesellschaft für Sportmedizin und Prävention). Due to these facts, University Departments of Sports Medicine (which vary greatly in size and performance) are either attached to Medical or non-Medical Faculties, such as Sports Sciences. In medical schools, sports medicine can be selected as an elective subject. However, the main part of teaching sports medicine is covered by Sports Science Faculties. In an international context, the strength of German sports medicine is its clinical orientation and close cooperation with the sport itself, especially high-performance sports. In the future, like in the Anglo- American countries, sports medicine in Germany will play a major role in health prevention and rehabilitation.

Exercise Therapy↗

PubMed2005

Freiburg Intervention Trial for Obese Children (FITOC): results of a clinical observation study.

BACKGROUND: The Freiburg Intervention Trial for Obese Children (FITOC) is an interdisciplinary, outpatient program for obese children consisting of regular physical exercise and comprehensive dietary and behavioral education. Parental involvement is required. The study is designed as a longitudinal, nonrandomized clinical observation study. An 8-month intensive phase preceded a follow-up phase of 1 y or longer. METHODS: Data were collected from 31 groups comprising 496 children (267 girls, 229 boys), with an average age of 10.5 y. Body height and weight, fasting total-cholesterol (CH), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C) and physical performance were measured initially and after 8.5 months. A group of n = 35 obese children (16 girls, 19 boys) who did not take part in this intervention program served as controls. RESULTS: After the intensive intervention phase, body mass index (BMI, kg/m2) as well as BMI deviation scores (BMI-SDS) decreased in both sexes (P<0.001). In the controls, BMI increased (P<0.001) and BMI-SDS remained constant. Whereas CH was only significantly lower (P<0.01) in boys after 8.5 months, LDL-C decreased significantly in both sexes. HDL-C tended to increase in both sexes (not significant). The controls showed no significant changes in CH, LDL-C and HDL-C. The fitness levels (W/kg body weight) improved in the intervention group (P<0.001), but not in the control group. CONCLUSIONS: The results indicate that obese children can be successfully treated in such an intervention program. BMI-SDS and risk factors decreased and physical performance improved. To maintain therapeutical success, we highly recommended that these children enroll in community-based exercise programs in order to help them maintain a more active lifestyle after the follow-up phase.

Body Mass Index↗

PubMed2005

Determining anaerobic capacity using treadmill ergometry.

The determination of anaerobic capacity (AC) using treadmill ergometry is problematic from a methodological, as well as a technical standpoint. In this study, a procedure from Monod and Scherrer was modified to examine whether realistic magnitudes of AC could be determined using three subject groups with different levels of anaerobic training. The subject groups consisted of 10 untrained (UT), 10 aerobic-trained runners (AeT), and 10 anaerobic-trained 400-meter sprinters (AnT). In two separate test series, first the VO2max was determined and second the so-called individual anaerobic threshold (IAT) was used to determine the aerobic power for all subjects. Then all subjects completed a series of sprints with increasing speeds above the VO2max, from which the work output from each test was calculated. Through linear regression, the point of intersection of the regression line with the y-axis was defined as global AC. The results show typically higher VO2max and IAT for AeT (62.2 ml x kg(-1) x min(-1), 14.7 km x h(-1)) compared to UT (53.2 ml x kg(-1) x min(-1); 11.2 km x h(-1)) and AnT (56.7 ml x kg(-1) x min(-1); 11.8 km x h(-1)). AC was significantly higher in AnT (4.1 +/- 0.58 kJ) compared to AeT (1.8 +/- 0.65 kJ) and UT (3.2 +/- 0.68 kJ). The determined absolute values of AC are considerably lower than of comparable examinations using bicycle ergometry. One reason for such an underestimation of AC could be that the horizontal work done during exercise on a treadmill was not taken into enough consideration. Another explanation is that the magnitude of the calculated AC values shows a dependency on the duration of each sprint test. In addition, the critical velocity for all subjects was found to be higher than for IAT, which consequently leads to an underestimation of AC. Moreover, the absolute level of the AC values appears to depend on the endurance of the comparison groups. It can then be concluded that the applied procedure allows for a differentiation amongst a variously trained collective, but does not allow a correct absolute determination of the AC.

Adult↗

PubMed2004

Antioxidant intervention does not affect the response of plasma erythropoietin to short-term normobaric hypoxia in humans.

Recent research has demonstrated that reactive oxygen species (ROS) participate in intracellular signaling processes initiated during hypoxia. We investigated the role of ROS in the response of plasma erythropoietin (Epo) to short-term normobaric hypoxia in humans. Twelve male subjects were exposed twice to 4 h of normobaric hypoxia (H; inspired oxygen fraction 12.5%) with a period of 6 wk between both experiments (H1 and H2). With the use of a randomized placebo-controlled crossover design, the subjects received orally a combination of the antioxidants all-rac-alpha-tocopherol (800 mg/day for 3 wk) and alpha-lipoic acid (600 mg/day for 2 wk) or placebo before H1 and H2, respectively. Three weeks before H1, the subjects underwent one control experiment in normoxia (N; inspired oxygen fraction 20.9%) without any treatment. Serum alpha-tocopherol was significantly higher after treatment with antioxidants compared with placebo. Capillary Po(2) declined during H without significant differences between antioxidants and placebo. Plasma peroxide levels were lower under antioxidant treatment but not affected by hypoxia. The response of Epo to H did not show significant differences between antioxidant [maximum increase (means, 95% confidence interval): +121%, +66 to +176%] and placebo conditions (+108%, +68 to +149%). Similarly, hypoxia-induced increase of Epo corrected for diurnal variations, as revealed during N, did not differ between antioxidants and placebo. Individual variability of Epo in response to H was not related to the individual degree of hypoxemia during H. Our results do not support the assumption that ROS play a major modulating role in the response of Epo to short-term normobaric hypoxia in humans.

Antioxidants↗

PubMed2003

Impact of elevated ambient temperatures on the acute immune response to intensive endurance exercise.

To date, there has been little research examining how elevated ambient temperatures exert an additional effect on the acute immune response to endurance exercise. Seven endurance-trained, non-heat-acclimated men [mean (95% confidence interval): 29.7 (25.9-33.5) years, .VO(2max) 66.3 (61.3-71.3) ml.kg(-1).min(-1)] performed two 60-min treadmill runs (75% .VO(2max)) in two different environments (EX1: 18 degrees C/50% room temperature/relative humidity and EX2: 28 degrees C/50% room temperature/relative humidity) with a 7-day interval between the runs. Blood samples were drawn at rest and 0, 0.5, 3, 24, and 48 h after exercise. Compared to EX1, exercise-induced increases in core temperature, sweating rate, heart rate, plasma norepinephrine, cortisol, human growth hormone, and neutrophil and monocyte counts were significantly (5% level) more pronounced after EX2. In contrast, responses of plasma epinephrine, myeloperoxidase, interleukin (IL)-6 as well as lymphocyte counts were similar in EX1 and EX2. Plasma concentrations of IL-8 and C-reactive protein were affected by neither exercise nor by additional heat exposure. Our results suggest that the additional impact of elevated ambient temperatures on stress responses to endurance exercise in trained subjects seems to affect primarily the cardiocirculatory and hormonal systems, and resulting changes in neutrophil and monocyte cell-trafficking. In contrast, heat stress does not seem to exert large additional effects on the acute immune response to endurance exercise as performed in the present study.

Acute-Phase Reaction↗

PubMed2003

Heart-rate recommendations: transfer between running and cycling exercise?

With the expanding use of portable heart rate (HR) monitors in endurance sports, HR is increasingly used as a marker for exercise intensity. Hereby, HR at the so-called individual anaerobic threshold (IAT) is one possible reference point. However, once determined, it is often attempted to apply HR recommendations from one type of ergometry to different kinds of exercises. We examined whether HR at IAT and at 4 mmol x l -1 blood lactate is predictable from cycling to running and vice versa. Data of 371 subjects (304 male, 67 female) were analyzed. All subjects underwent an incremental test on a treadmill (TR, starting speed 6 or 8 km x h -1, increments 2 km x h -1 every 3 min) and on a bicycle ergometer (BE, start at 50 Watt, increments 25 or 50 Watt every 3 min). IAT was determined at a net increase of lactate concentration of 1 - 5 mmol x l -1 above lactate concentration at lactate threshold for running (as in: Med Sci Sports Exerc 1998, 30 (10); 1552 - 1557) and 1.0 mmol x l -1 for cycling. A maximum time span of three weeks was allowed between the tests. We found that heart rate at IAT or at 4 mmol x l -1 blood lactate did not correlate between cycling and running. A sports specific test seems to be a prerequisite for reliable heart rate recommendations.

Adult↗

PubMed2002

Basal expression of leukocyte iNOS-mRNA is attenuated in moderately endurance-trained subjects.

Nitric oxide (NO) is generated in immunocompetent cells by inducible NO-synthase (iNOS), and plays an important role in host defense. However, when produced in large amounts, NO can also exert damaging effects, a scenario that is observed during several inflammatory processes. In the study presented here, we investigated the impact of moderate endurance training (running volume: mean 53.1 km x week(-1), 95% confidence interval 41.2-65.1 km week(-1)) on the leukocyte expression of iNOS mRNA. Semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis was used to examine iNOS mRNA expression in total leukocyte samples from 12 male trained subjects (TR) and a control group of 12 untrained men (UT) at rest. Relative iNOS mRNA levels (iNOS/beta-actin) were higher in UT (0.88, 0.73-1.03) when compared with TR (0.34, 0.09-0.58, P<0.001). iNOS mRNA was not detectable in 5 of the 12 TR subjects. These initial results show that the basal expression of iNOS mRNA is downregulated by moderate endurance training. Further research should clarify whether regular training also affects the responsiveness of leukocyte iNOS gene expression to stimulatory signals. It would be of interest to establish whether moderate training can exert a suppressive and therefore therapeutic effect on the elevated levels of expression of iNOS observed in, for example, several inflammatory disorders.

Adult↗

PubMed2002

Exercise-induced, persistent and generalized muscle cramps. A case report.

We are reporting on a 46-year-old man who has suffered of muscle cramps for 4 years, occurring immediately after jogging and playing tennis and lasting for 7-8 hours. Repeated neurological, orthopedic, internal medical and endocrinological examinations showed no pathological findings. Physiotherapy, supplementation of fluids and electrolytes had no effect, nor did medication therapy with muscle relaxants. During spiroergometry without medication, there was an overproportional increase of heart rate and respiratory rate with delayed pCO2 increase after exercise with otherwise normal blood gas levels. This reaction was considerably reduced during spiroergometry under beta-blockade (metoprolol 100 mg); at the same time, the muscle cramps could no longer be induced. Both excessive respiratory regulation and direct hyperadrenergic stimulation should be discussed as the primary cause of the muscle cramps. According to recent findings, b-blockers with intrinsic sympathocomimetic activity should be avoided in therapy.

Adrenergic beta-Antagonists↗

PubMed2002

Combating drug use in competitive sports. An analysis from the athletes' perspective.

BACKGROUND: Doping has developed into a widespread problem in competitive and high-performance sports due to increasing professionalism in, and commercialization of sports. In contrast, governments and sports organizations have limited financial resources to support all competitive sports. Therefore, further improvement of anti-doping measures can only be achieved through the inclusion and active participation of the athletes themselves. METHODS: In this study, 101 German athletes who are subject to national and international anti-doping tests were asked if doping in sports should be combatted, and which anti-doping measures appeared effective from an athlete's perspective. RESULTS: Ninety-eight point zero two per cent of those questioned felt that measures should be taken against doping in sports. Improved methods of detection and more information on the health risks were favored, as opposed to more severe punishments. In addition, more than two thirds of the athletes supported the introduction of an anti-doping law. The desire for more frequent drug testing was also expressed, despite the distinct invasion of the athletes' privacy. CONCLUSIONS: An anti-doping law, as requested by the athletes, should include measures for educating the public about the health risks involved with doping. In addition, such a law would also make it possible to develop suitable methods of detection.

Adolescent↗