Cell-free DNA release under psychosocial and physical stress conditions.

The understanding of mechanisms linking psychological stress to disease risk depend on reliable stress biomarkers. Circulating cell-free DNA (cfDNA) has emerged as a potential biomarker of cellular stress, aging, inflammatory processes, and cell death. Recent studies indicated that psychosocial stress and physical exercise might also influence its release. We compared the effects of acute psychosocial and physical exercise stress on cfDNA release by exposing 20 young, healthy men to both an acute psychosocial laboratory stressor and an acute physical exercise stressor. Venous blood and saliva samples were collected before and after stress exposure. Cell-free DNA was extracted from plasma and quantified by qPCR. Furthermore, cfDNA fragment length was analyzed and cfDNA methylation patterns were assayed across time. In addition, release of stress hormones and subjective stress responses were measured. Results showed a twofold increase of cfDNA after TSST and fivefold increase after exhaustive treadmill exercise, with an overabundance of shorter cfDNA fragments after physical exhaustion. Interestingly, cell-free mitochondrial DNA showed similar increase after both stress paradigms. Furthermore, cfDNA methylation signatures-used here as a marker for diverse cellular origin-were significantly different post stress tests. While DNA methylation decreased immediately after psychosocial stress, it increased after physical stress, suggesting different cellular sources of active DNA release. In summary, our results suggest stimulus and cell-specific regulation of cfDNA release. Whereas the functional role of stress-associated cfDNA release remains elusive, it might serve as a valuable biomarker in molecular stress research as a part of the psychophysiological stress response.

[Higher - Further - Faster]. / Höher - weiter - schneller.

The striated skeletal muscles consist of different myocytes that have different metabolic and contractile characteristics. They react in a specific way to difference training stimuli: adaptations as a result of endurance training trigger an increase in mitochondria and lead to an intensified oxidative metabolism. Adaptations as a result of strength training result in increased protein biosynthesis and hypertrophy of the skeletal myocytes. About 50 % of the adaptation associated with endurance training are due to genetic factors.The molecular mechanisms that underlie the training adaptations are currently the subject of intense research. They comprise complex interrelated systems with a series of key components. Understanding molecular switches and signalling pathways gives rise to the assumption that the combination of simultaneous strength training and endurance training is counterproductive. The combination of both these forms of training possible weakens the effect on muscle mass and muscle strength. Consequently the recommendation is to plan for enough of time intervals between strength training and endurance training.

Sports and brain morphology - a voxel-based morphometry study with endurance athletes and martial artists.

Physical exercises and motor skill learning have been shown to induce changes in regional brain morphology, this has been demonstrated for various activities and tasks. Also individuals with special skills show differences in regional brain morphology. This has been indicated for professional musicians, London taxi drivers, as well as for athletes like dancers, golfers and judokas. However little is known about whether sports with different metabolic profiles (aerobic vs. anaerobic) are associated with different patterns of altered brain morphology. In this cross-sectional study we investigated two groups of high-performance athletes, one group performing sports that are thought to be mainly aerobic, and one group performing sports known to have intermittent phases of anaerobic metabolism. Using high-resolution structural imaging and voxel-based morphometry (VBM), we investigated a group of 26 male athletes consisting of 13 martial artists and 13 endurance athletes as well as a group of non-exercising men (n=13). VBM analyses revealed higher gray matter (GM) volumes in the supplementary motor area/dorsal premotor cortex (BA 6) in both athlete groups as compared to the control group. In addition, endurance athletes showed significantly higher GM volume in the medial temporal lobe (MTL), specifically in the hippocampus and parahippocampal gyrus, which was not seen in the martial arts group. Our data suggest that high-performance sports are associated with changes in regional brain morphology in areas implicated in motor planning and motor learning. In addition high-level endurance sports seem to affect MTL structures, areas that have previously been shown to be modulated by aerobic exercise.

An exercise programme for community-dwelling, mobility-restricted and chronically ill older adults with structured support by the general practitioner's practice (HOMEfit). From feasibility to evaluation.

Programmes containing health-enhancing physical exercise should be evaluated using standards that are just as rigorous as those required for drug development. In contrast to new medicines, exercise programmes are highly complex. This has to be taken into account when designing the research plan. In order to illustrate the development process of a "complex intervention", we use the example of an exercise programme for community-dwelling, mobility-restricted and chronically ill older adults. Based on a framework for evaluation of complex interventions (Medical Research Council [MRC], UK), a research plan was set up containing the phases: development, feasibility, evaluation, implementation. The development phase resulted in the design of a home-based exercise programme in which the target group is approached and supported via their general practitioner and an exercise therapist. A feasibility study was performed. Three quantitative criteria for feasibility (adoption, safety, continuing participation) were statistically confirmed which permitted the decision to proceed with the research plan. So far, the MRC framework has proved to be valuable for the development of the new programme.

Exercise in cold air and hydrogen peroxide release in exhaled breath condensate.

Athletes have changes in the lung epithelial cells caused by inhalation of cold and dry air. The exhaled breath condensate contains a number of mediators from the respiratory system and H(2)O(2) is described as a marker of airways inflammation. The aim of this study was to determine the influence of exercise combined with cold air on the H(2)O(2) release in the exhaled breath. Twelve males (23.1 ± 1.5 years) were randomly assigned at 2 different days (1 day rest) to perform a 50 min run (75-80% of their max. heart rate) under normal (N) laboratory (18.1 ± 1.1°C) or cold (C) field condition (-15.2 ± 3.1°C). Before and immediately after each run, the EBC was collected under laboratory conditions and was analyzed amperometrically. Prior to the two runs, H(2)O(2) concentrations were 145.0 ± 31.0 (N) and 160.0 ± 49.1 nmol/L (C) and theoretical release was 70.3 ± 37.1 (N) and 82.6 ± 27.1 pmol/min (C) (p > 0.05). After each run, H(2)O(2) concentration increased significantly to 388.0 ± 22.8 nmol/L (N) and 622.1 ± 44.2 nmol/L (C) (p < 0.05), along with an increase in the theoretical release: 249.2 ± 35.7 pmol/min (N) and 400.9 ± 35.7 pmol/min (C) (p < 0.05). We conclude that release of H(2)O(2) into the EBC takes place under both resting conditions and after exercise. The concentration and release of H(2)O(2) increased after exercise in cold air compared to resting and laboratory conditions, which points to an increase in inflammatory and oxidative stress.

[Measurement of physical activity in older adults. Correlation between the PRISCUS-PAQ and accelerometry]. / Messung körperlicher Aktivität bei älteren Erwachsenen. Übereinstimmung zwischen PRISCUS-PAQ und Akzelerometrie.

BACKGROUND: The German questionnaire PRISCUS-PAQ was developed to measure actual physical activity of older adults in a telephone interview. PRISCUS-PAQ consists of ten main questions to assess the time spend in domestic activities (e.g., housework, gardening), sporting activities (e.g., riding a bicycle), and inactivity (e.g., sedentary activity, sleeping during the day) during the prior week. By assessing the number of days for each activity and the mean duration of performing this activity, a total score can be calculated. The total score corresponds to the energy consumption for 1 week. The aim of this study is to estimate the correlation of the PRISCUS-PAQ total score and accelerometry as an objective measurement method for the assessment of physical activity. MATERIAL AND METHODS: A total of 114 participants (58% women) with a mean age of 76 years participated in the study. PRISCUS-PAQ was initially analyzed descriptively. To assess the validity of PRISCUS-PAQ, the correlation (correlation coefficient of Spearman) was calculated between the total score of the questionnaire PRISCUS-PAQ and the 95% trimmed sum of an accelerometer with a measurement period of 1 week. RESULTS: The correlation coefficient for the association of the PRISCUS-PAQ total score and the 95% trimmed sum of the acceleration values was r = 0.28 (95% confidence interval 0.10­0.44). Activities of daily life like cleaning and other domestic activities highly contributed to the weekly energy consumption of the participants. CONCLUSION: The association between the PRISCUS-PAQ questionnaire and accelerometry measured physical activity is comparable to other validated and established international questionnaires. The PRISCUS-PAQ is the first German questionnaire that allows the measurement of physical activity of older adults in a telephone interview.

[Injuries of the musculoskeletal system in German elite rowers]. / Beschwerden des Bewegungsapparats bei deutschen Hochleistungsruderern.

BACKGROUND: Elite rowers on national and international level are exposed to considerable impact on the musculoskeletal system. The aim of this study was to give an overview of the training load and the injuries of the musculoskeletal system in German elite rowers during the Olympic year. METHODS: A sample of 29 female rowers aged 22.2 ± 3.1 years and 38 male rowers aged 22.3 ± 3.1 years of German national team has been interviewed about training contents and training volume as well as about musculoskeletal injuries (current and over the past 12 months). Furthermore the athletes were asked to declare the supposed reason for the injuries. RESULTS: Rowers trained on average 22.8 ± 5.3 hours in 16.0 ± 4.6 training sessions per week. The most frequently reported injuries during the 12-month period were at the lumbar spine/buttock (50.0 % of interviewees), followed by the shoulder girdle (33.9 %), the forearm/hand (32.2 %), the cervical spine (31.6 %) and the thoracic spine (28.1 %). The most frequently reported reason for injuries was "overuse" in all regions. CONCLUSIONS: This study confirms a high prevalence of musculoskeletal injuries in German elite rowers and supports the demand for adequate preventive measures.

[Back pain, pain therapy and satisfaction with therapy--analyses in a cohort of elderly primary health care patients (getABI)]. / Rückenschmerz, Schmerztherapie und Therapiezufriedenhei--Analyse einer Kohorte älterer Hausarztpatienten (getABI).

INTRODUCTION: Back pain can affect quality of life and independence of elderly people. The goal of this study was to determine the prevalence of back pain in a cohort of elderly primary health care patients, as well as to analyse pain therapy and level of satisfaction with therapy. METHODS: In a monitored prospective cohort study (German epidemiological trial on ankle brachial index, getABI), 6 880 unselected patients aged 65 years and above have been followed up by 344 representative primary care physicians in Germany since October 2001. In the 5-year follow-up, 2 120 patients (median age 76; 70-94 years; 53.7% women) were interviewed by telephone about location and intensity of pain during the past 3 months, about impairment due to pain, about pain therapy and satisfaction with therapy. RESULTS: Of the 2 095 patients who answered the questions on pain, 803 (38.3%) had suffered from pain of the upper and/or lower back within the past 3 months. The prevalence of back pain was higher in female than in male patients (45.0% vs. 30.6%; p<0.05). In about half of the men and half of the women with back pain, the back was also the main pain region. This subsample (n=409) with the back as main pain region (BMP) was analysed in more detail. The mean "von Korff intensity score" (scale 0-100) was 46.5±19.9, the mean "von Korff impairment score" (scale 0-100) was 23.6±23.0. Women reported a higher mean intensity of back pain than men (48.8±20.0 vs. 42.4±19.3; p<0.05) and complained about a higher pain-related impairment (26.2±23.5 vs. 19.2±21.5; p<0.05). Of all BMP patients, 253 (61.9%) visited a physician (at least once) during the past 3 months due to pain. The treatments most frequently applied (multiple answers permitted) were: oral medication (62.5%), injections (38.6%), and physiotherapy (35.9%). Patients (n=224) were asked to rate the therapy on a scale from 1 to 6 (1 being the highest grade). The mean rating was 3.1±1.4. 36.8% were not satisfied with pain relief. 61.4% wished for a considerable improvement of their pain therapy. CONCLUSION: The prevalence of back pain in elderly people is high and leads to functional limitations. As a consequence of the rather low mean satisfaction with pain therapy, future studies on back pain therapy should include an assessment of patient preferences and satisfaction with therapy. It remains questionable, if the current medical care for elderly people with back pain complies with the latest guidelines that demand for multimodal therapy.

Rapid determination of urinary di(2-ethylhexyl) phthalate metabolites based on liquid chromatography/tandem mass spectrometry as a marker for blood transfusion in sports drug testing.

Methods of blood doping such as autologous and homologous blood transfusion are one of the main challenging doping practices in competitive sport. Whereas homologous blood transfusion is detectable via minor blood antigens, the detection of autologous blood transfusion is still not feasible. A promising approach to indicate homologous or autologous blood transfusion is the quantification of increased urinary levels of di(2-ethylhexyl) phthalate (DEHP) metabolites found after blood transfusion. The commonly used plasticizer for flexible PVC products, such as blood bags, is DEHP which is known to diffuse into the stored blood. Therefore, a straight forward, rapid and reliable assay is presented for the quantification of the main metabolites mono(2-ethyl-5-oxohexyl) phthalate, mono(2-ethyl-5-hydroxyhexyl) phthalate and mono(2-ethylhexyl) phthalate that can easily be implemented into existing multi-target methods used for sports drug testing. Quantification of the DEHP metabolites was accomplished after enzymatic hydrolysis of urinary glucuronide conjugates and direct injection using isotope-dilution liquid chromatography/tandem mass spectrometry. The method was fully validated for quantitative purposes considering the parameters specificity, linearity (1-250 ng/mL), inter- (2.4%-4.3%) and intra-day precision (0.7%-6.1%), accuracy (85%-105%), limit of detection (0.2-0.3 ng/mL), limit of quantification (1 ng/mL), stability and ion suppression effects. Urinary DEHP metabolites were measured in a control group without special exposure to DEHP (n = 100), in hospitalized patients receiving blood transfusion (n = 10), and in athletes (n = 468) being subject of routine doping controls. The investigation demonstrates that significantly increased levels of secondary DEHP metabolites were found in urine samples of transfused patients, strongly indicating blood transfusion.

Prerequisites for a new health care model for elderly people with multimorbidity: the PRISCUS research consortium.

BACKGROUND: Multimorbidity, the concurrent manifestation or presence of multiple chronic conditions, poses huge challenges to affected patients, their relatives, physicians, and practitioners alike. The growing number of affected persons and the complexity of their needs places just as much of a burden on the health care system as does the plethora of often poorly coordinated interventions. The Chronic Care Model developed for different chronic diseases is suited for improving medical care. The PRISCUS research consortium was established to create the prerequisites for a new care model for multimorbid, elderly patients oriented along those lines. METHODS: The research consortium utilizes data gathered in a large-scale epidemiological study on peripheral arterial disease (getABI study) and from the Dortmund and Münster stroke registries, by extracting epidemiologic and health economic data, quality-of-life parameters, and data on the extent and quality of medication. Additional projects evaluate the implementation of a multidimensional geriatric assessment in primary care, the functional consequences of multimorbidity in stroke patients along with options for prevention and therapy afforded by physical activity. Systematic reviews of the literature are used to describe quality of life and patient preferences. Experts will work on an initial draft treatment standard for patients with multimorbidity and a list of potentially inappropriate medication for the elderly in Germany. CONCLUSION: The results of the PRISCUS research consortium will enable an epidemiologic characterization and description of consequences of multimorbidity, while illustrating new approaches towards prevention, diagnosis, and management of multimorbid patients. With this, some prerequisites for a new health care model for patients with multimorbidity comparable to the Chronic Care Model will be fulfilled.

[Prerequisites for a new health care model for elderly people with multiple morbidities: results and conclusions from 3 years of research in the PRISCUS consortium]. / Voraussetzungen für ein neues Versorgungsmodell für ältere Menschen mit Multimorbidität: Ergebnisse und Schlussfolgerungen aus 3-jähriger Forschung im PRISCUS-Verbund.

BACKGROUND: The concurrent presence or manifestation of multiple chronic conditions, i.e. multimorbidity, poses a challenge to affected patients and their relatives, physicians, and practitioners, and to the health care system in general. Aiming to improve medical care for different chronic diseases, the Chronic Care Model also appears to be suited for multimorbidity. The established research consortium PRISCUS is trying to create some of the prerequisites for a new care model for multimorbid, elderly patients oriented along the lines of the Chronic Care Model. METHODS AND RESULTS: Four out of seven subprojects of the research consortium provide an overview of some of their findings. Topics in a sports medicine subproject were the assessment of physical activity by means of a newly developed questionnaire and the development and feasibility testing of an exercise program for elderly people with chronic conditions and mobility impairment. Partners from family medicine implemented geriatric assessment in a primary care setting and evaluated its consequences. In a pharmacological subproject, potentially inappropriate medication as well as drug-drug interactions and dosing errors were addressed. The health economic subproject investigated quality of life impairment due to multiple chronic diseases and the effects of multimorbidity on costs. CONCLUSIONS: The results of the PRISCUS research consortium allow a better description of consequences of multimorbidity and illustrate at least some new approaches towards prevention, diagnosis, and treatment of patients suffering from multimorbidity. Ongoing projects will test the efficacy of a physical activity program and a new complex intervention to reduce potentially inappropriate medication in the elderly. With this, the research consortium will create some prerequisites for a new health care model for patients with multimorbidity comparable to the Chronic Care Model.

[Reliability of the PRISCUS-PAQ. Questionnaire to assess physical activity of persons aged 70 years and older]. / Reliabilität des PRISCUS-PAQ. Fragebogen zur Erfassung körperlicher Aktivität von Personen im Alter von 70 Jahren und älter.

A questionnaire (Q) to measure physical activity (PA) of persons ≥70 years for epidemiological research is lacking. The aim was to develop the PRISCUS-PAQ and test the reliability in community-dwelling people (≥70 years). Validated PA questionnaires were translated and adapted to design the PRISCUS-PAQ. Its test-retest reliability for 91 randomly selected people (36% men) aged 70-98 (76±5) years ranged from 0.47 (walking) to 0.82 (riding a bicycle). The overall activity score was 0.59 as determined by the intraclass correlation coefficient (ICC). Recording of general activities, e.g., housework (ICC=0.59), was in general less reliable than athletic activities, e.g., gymnastics (ICC=0.76). The PRISCUS-PAQ, which is a short instrument with acceptable reliability to collect the physical activity of the elderly in a telephone interview, will be used to collect data in a large cohort of older people in the German research consortium PRISCUS.

Measurements of lactate in exhaled breath condensate at rest and after maximal exercise in young and healthy subjects.

Arterial lactate concentrations, taken as indicators of physical fitness, in athletes as well as in patients with cardio-respiratory or metabolic diseases, are measured invasively from arterialized ear lobe blood. Currently developed micro enzyme detectors permit a non-invasive measurement of hypoxia-related metabolites such as lactate in exhaled breath condensate (EBC). The aim of our study is to prove whether this technology will replace the traditional measurement of lactate in arterialized blood. Therefore, we determined the functional relation between lactate release in EBC and lactate concentration in blood in young and healthy subjects at rest and after exhausting bicycle exercise. During resting conditions as well as after exhausting bicycle exercise, 100 L of exhaled air along with blood samples from the ear lobe was collected after stationary load conditions in 16 healthy subjects. EBC was obtained by cooling the expired air volume with an ECoScreen I (FILT GmbH, Berlin) condenser. The analysis was performed within 90 min using an ECoCheck ampere meter (FILT GmbH, Berlin). Lactate measurements were performed using a bi-enzyme sensor after lactate oxidase-induced oxidation of lactate to pyruvate and H2O2. The rates of lactate release via the exhaled air were calculated from the lactate concentration, the volume and the collection time of the EBC. The functional relation of lactate release in exhaled air and lactate concentration of arterial blood was computed. At rest, the mean lactate concentration in arterialized blood was 0.93 ± 0.30 mmol L(-1). At a resting ventilation of 11.5 ± 3.4 L min(-1), the collection time for 100 L of exhaled air, Ts, was 8.4 ± 2.9 min, and 1.68 ± 0.40 mL EBC was obtained. In EBC, the lactate concentration was 21.4 ± 7.7 µmol L(-1), and the rate of lactate release rate in collected EBC was 4.5 ± 1.7 nmol min(-1). After maximal exercise load (220 ± 20 W), the blood lactate concentration increased to 10.9 ± 1.8 mmol L(-1) and the ventilation increased to 111.6 ± 21.4 L min(-1). The EBC collection time decreased to 3.9 ± 1.9 min, and 1.20 ± 0.44 mL EBC were obtained in the recovery period after termination of exercise. The lactate concentration in EBC increased to 40.3 ± 23.0 µmol L(-1), and the lactate release in EBC increased to 13.6 ± 8.6 nmol min(-1) (p < 0.01). Assuming a volume of 4.3 mL water in 100 L of exhaled air (saturated with water at 37 °C), we calculated a lactate release at rest of 11.5 ± 4.3 nmol min(-1) and 48.6 ± 30.7 nmol min(-1) (p < 0.01) after exhausting exercise. Detectable releases of lactate in exhaled breath condensate were found already under resting conditions. During exhausting external load on a bicycle spiroergometer, an increase in the lactate concentration was found in arterialized blood along with an increased lactate release in EBC. The correlation between expiratory lactate release via EBC and lactate concentration in arterialized blood is studied in pursuing investigations.

Voxel-based morphometry reveals an association between aerobic capacity and grey matter density in the right anterior insula.

This study investigated the effects of aerobic capacity on brain structure and memory performance. A sample of 33 healthy young subjects completed (i) assessment of aerobic capacity based on blood-lactate concentration, (ii) structural magnetic resonance imaging (MRI) scanning and analysis of grey matter density using voxel-based morphometry (VBM) and (iii) a range of memory tests. Memory performance was not significantly associated with aerobic capacity. After adjusting for effects of age, gender and total intracranial volume, cortical grey matter density in the right anterior insula was strongly correlated with aerobic capacity. These findings are in line with studies implicating the insula in the cortical control of cardiovascular processes during both exercise and autonomic arousal. Interindividual differences in aerobic capacity are thus reflected in structural differences in brain regions involved in cardiovascular control, resembling structural changes associated with certain cognitive or motor skills.

Short intensive exercise increases the migratory activity of mesenchymal stem cells.

BACKGROUND: It is known that exercise increases the number of stem cells within the circulation; however, it has not been clear which cellular processes are responsible for this increase. To answer this question, we analysed the influence of athletes' blood sera on human mesenchymal stem cells (MSC). METHODS: Sera were taken before and after short intensive exercise. As cellular parameters of MSC proliferation, apoptosis and migratory activity were analysed. RESULTS: A change in stimulation of proliferation or apoptosis was not seen after exercise. In contrast, the migratory activity of MSC was significantly increased after exercise. To identify potential factors that could be responsible for this effect, we also analysed the semiquantitative serum concentration of 120 cytokines. Of these factors brain-derived neurotrophic factor, cutaneous T-cell-attracting chemokine, epidermal growth factor receptor, glucocorticoid-induced tumour necrosis factor receptor ligand, growth-regulated oncogene-alpha, interleukin (IL)1a, IL6, IL8, IL15, pulmonary and activation-regulated chemokine and soluble tumour necrosis factor receptor II showed a significant increase whereas migration inhibitory factor howed a decrease in concentration after exercise. CONCLUSIONS: IL6 is known to stimulate migration in MSC. It is recognised that contracting skeletal muscles synthesise and release IL6 into the systemic circulation in response to exercise. We therefore hypothesise that there is a direct relationship between exercise, IL6 release and stem cell recruitment.

Hydrogen peroxide release and acid-base status in exhaled breath condensate at rest and after maximal exercise in young, healthy subjects.

OBJECTIVE: Exhaled breath condensate (EBC) contains among a large number of mediators hydrogen peroxide (H2O2) as a marker of airway inflammation and oxidative stress. Similarly EBC pH also changes in respiratory diseases. It was the aim of our investigation to prove if hydrogen peroxide release and changes in pH of EBC changes with exercise. METHODS: EBC was collected from 100 litres exhaled air along with samples of arterialized blood of 16 healthy subjects (9 males, 7 females, age 23 +/- 1 years). EBC hydrogen peroxide was analyzed with EcoCheck amperometer (FILT, Berlin). The rate of H(2)O(2) release was calculated from the concentration and collection time. pH and PCO(2) in blood and in EBC were measured with the Radiometer blood gas analyzer, EBC was equilibrated with a gas mixture (5% CO(2) in O(2)). The bicarbonate concentration was calculated according to the law of mass action for CO(2) and HCO(3)(-) (pK = 6.1). RESULTS: H(2)O(2) concentration in EBC was 190 +/- 109 nmol/l, and H (2)O(2) release at rest was 31.0 +/- 18.3 pmol/min. At maximal exercise, the H(2)O(2) concentration in EBC increased to 250 +/- 120 nmol/l, and H(2)O(2) release significantly increased at maximal exercise to 84.4 +/- 39.9 pmol/min (P<0.01). At rest pH of the CO(2) equilibrated EBC was at 6.08 +/- 0.23 and the [HCO(3)(-)] was 1.03 +/- 0.40 mmol/l. At maximum exercise, pH 6.18 +/- 0.17 and [HCO(3)(-)] 1.23 +/- 0.30 mmol/l remained almost unaltered. CONCLUSIONS: The rate of H(2)O(2) release in EBC increased during exhausting exercise (external load: 300 Watt) by a factor of 2, whereas the pH and the bicarbonate concentration of the EBC, equilibrated with 5% CO(2) at 37 degrees C were not significantly altered. It has to be proven by further experiments whether there is a linear relationship between the rates of H(2)O(2) release in EBC in graded submaximal exercise.

Energy expenditure in ball games for wheelchair users.

PURPOSE: Wheelchair sports have become popular in Germany. This is important because of the difficulty experienced by wheelchair-dependent people in maintaining cardiovascular health and fitness by daily activities. Increasing energy expenditure (EE; kcal h(-1)) is one of the most effective ways of decreasing risk of cardiovascular disease. The purpose of this study was to evaluate the EE of individuals with spinal cord injury in ball games for wheelchair-dependent persons. METHODS: Fourteen tennis players (WT), 10 basketball players (WB) and 12 rugby players (WR) completed a basal metabolism evaluation and a training test to measure respiratory parameters. RESULTS: In the basal metabolism test EE in WT was 66.8+/-12.8 kcal h(-1), in WB 62.7+/-15.0 kcal h(-1) and in WR 63.5+/-12.9 kcal h(-1). During training EE in WT was 325.8+/-73.0 kcal h(-1), in WB 374.8+/-127.1 kcal h(-1) and in WR 248.5+/-69.4 kcal h(-1). The average EE of the whole group was: 316.4+/-89.6 kcal h(-1) with a corresponding heart rate of 118.5+/-23.1 b.p.m. and a lactate concentration of 2.09+/-0.7 mmol l(-1). Statistical analysis showed significantly lower values of EE, heart rate and oxygen uptake for the WR group in comparison to the other groups. CONCLUSION: The results indicate that the additional leisure time EE of persons participating in WB and WT is sufficient to maintain fitness. This level of EE is comparable to the recommendations of the ACSM for able-bodied persons, and therefore might be sufficient to prevent the development of cardiovascular diseases.

Performance diagnostics in handbiking during competition.

STUDY DESIGN: Case study in handbiking under competition conditions. OBJECTIVE: To investigate exercise-induced, metabolic, pulmonary, cardiovascular and energetic reactions of a paraplegic athlete during a city marathon. SETTING: City marathon Cologne, Germany. SUBJECT: We tested a 27-year-old male athlete from the German national team. The handicap of the athlete was a complete traumatic spinal cord injury ASIA/IMSOP Grade A at the level of the fourth thoratic vertebra (Th4). METHOD: In the competition, the athlete used his own race handbike whose crank system had been exchanged for a power measurement system with registering option. For measuring ventilatory gas parameters during exercise, a portable spirometric system was used. The athlete managed to finish the marathon race in 1:48:54 h. RESULTS: The mean oxygen uptake (VO2) during the marathon was 1580 ml/min, with a maximum value of 2535 ml/min. The mean heart frequency was 137 bpm with a maximum of 157 bpm. During the race the mean energy consumption was 463 kcal/h with a maximum of 758 kcal/h. Prior to the race, the blood lactate value was 2.9 mmol/l; after 10 km 4.4 mmol/l; after 20 km 2.9 mmol/l, and after 30 km 2.9 mmol/l. CONCLUSION: Competition-oriented handbikers should concentrate on exercise units of long duration at low intensities--like marathon runners or cyclists--in order to improve their aerobic performance capacity. However, it has to be pointed out that paraplegic athletes develop relatively high metabolic intensities in competition and that the variability of their physiological parameters is considerably high.

Correlation between BMI, leisure habits and motor abilities in childhood (CHILT-project).

INTRODUCTION: The prevalence of childhood obesity is increasing with its negative medical and psychosocial consequences. This paper examines the association between body mass index (BMI), motor abilities and leisure habits of 668 children within the CHILT (Children's Health InterventionaL Trial) project. METHOD: A total of 668 children (51.0% boys; 49.0% girls) and their parents were questioned on sport and leisure behaviour of the children. The anthropometric data were measured. Motor abilities were determined by a body gross motor development test for children (Köperkoordinationstest für Kinder; KTK) and a 6-min run. RESULTS: The children were 6.70 +/- 0.42 y old, 122.72 +/- 5.36 cm tall and weighed 24.47 +/- 4.59 kg, the average BMI was 16.17 +/- 2.27 kg/m2. KTK showed an average motor quotient (MQ) of 93.49 +/- 15.01, the 6-min run an average of 835.24 +/- 110.87 m. Both tests were inversely correlated with BMI (KTK and BMI r=-0.164 (P<0.001); 6-min run and BMI r=-0.201 (P<0.001)); the group of overweight/obese children showed poorer results than the normal/underweight ones, even after adjustment for gender and age (in each case P<0.001). Children with the greatest extent of exercise achieve the highest MQ (P=0.035). SUMMARY: Overweight/obesity is associated with a poorer body gross motor development and endurance performance. On the other hand, an active lifestyle is positively correlated with a better gross motor development in first-grade children. Therefore, to prevent the negative consequences of physical inactivity and overweight/obesity early intervention to support exercise and movement is recommended.

Evidence for an acute rise of intestinal calcium absorption in response to aerobic exercise.

BACKGROUND: The acute effects of physical activity on intestinal calcium (Ca) uptake and on bone metabolism are not known. AIM OF THE STUDY: To investigate the consequences of an acute aerobic exercise bout on fractional Ca absorption and on biomarkers of bone turnover. METHODS: With the use of a cross over design, eighteen male athletes, aged 25.2 (SE 0.6) years, either had to perform a 60 min run (70 % of maximal speed) or had to rest for 60 min. Intestinal Ca absorption (Fc(240)) was assessed by the use of a stable strontium test. Moreover, calciotropic hormones and serum C-Telopeptide (CTx), a biomarker of bone collagen degradation, and serum C-terminal propeptide of type I collagen (PICP), a marker of bone collagen formation, were measured prior (t(-60)) and 3 hours after (t(240)) exercise or rest. RESULTS: Fc(240) values were significantly enhanced in response to exercise compared to rest (16.2 +/- 0.7 % vs. 14.6 +/- 0.8 %; P < 0.05). PICP values were significantly lower in response to exercise compared to rest: -9.8 % (P < 0.05). Exercise did not influence serum levels of intact parathyroid hormone and calcitriol. Serum CTx levels decreased markedly between t(-60) and t(240) during both intervention periods (both P values < 0.001), the results being in line with the circadian rhythm of serum CTx. CONCLUSIONS: A moderate exercise bout can induce an acute rise in fractional Ca absorption. Moreover, even in endurance-trained young men a moderate exercise bout acutely decreases bone collagen formation, while the physiologic fluctuations of the bone resorption marker CTx remain unaffected.