[Current Guidelines to Prevent Obesity in Childhood and Adolescence]. / Aktuelle Empfehlungen zur Prävention der Adipositas im Kindes- und Jugendalter.

BACKGROUND: Current guidelines for the prevention of obesity in childhood and adolescence are presented. METHODS: A literature search was performed in Medline via PubMed, and appropriate studies were analysed. RESULTS: Programs to prevent childhood obesity were to date mainly school-based. Effects were limited to date. Analyses tailored to different age groups show that prevention programs have the best effects in younger children (< 12 years). Evidence based recommendations for preschool- and early school age imply the need for interventions addressing parents and teachers alike. During adolescence, school-based interventions were most effective when adolescents were directly addressed. To date, obesity prevention programs have mainly focused on behavior oriented prevention. Recommendations for condition oriented prevention have been suggested by the German Alliance of Non-communicable Diseases and include one hour of physical activity at school, promotion of healthy food choices by taxing unhealthy foods, mandatory quality standards for meals at kindergarten and schools as well as a ban on unhealthy food advertisement addressing children. CONCLUSION: Behavior oriented prevention programs showed hardly any or only limited effects in the long term. Certain risk groups for the development of obesity are not reached effectively by available programs. Due to the heterogeneity of available studies, universally valid conclusions cannot be drawn. The combination with condition oriented prevention, which has to counteract on an obesogenic environment, is crucial for sustainable success of future obesity prevention programs.

"Obese equals lazy?" analysis of the association between weight status and physical activity in children.

INTRODUCTION: Literature provides evidence that overweight children are more sedentary. To verify this generalized statement behavior patterns of overweight and nonoverweight children needs to be understood. Therefore, we investigated the distribution of sedentary and activity levels in a quantitative and qualitative way. METHODS: Data was collected from 37 randomly selected nonoverweight and 55 overweight children. They were 8 to 11 years of age. Height and weight were measured and weight status was characterized by BMI (BMI-percentile, BMI-SDS). Daily PA (physical activity) was measured by direct accelerometry. Spare time and screen time entertainment were obtained by questionnaires. RESULTS: The amount of time spent "passive" was significantly higher in overweight children, while nonoverweight children were more "active." The multiple regression model shows a significant association between weight status (BMI-SDS) and activity parameters. Additionally, screen time entertainment was significantly related to BMI-SDS. CONCLUSION: The results support the statement that overweight children are less active than nonoverweight children. The high amount of PA seems to be an important factor to prevent overweight in children given that PA shows the highest correlation to weight status. Quantitative and qualitative measurements are needed for further analysis.

Hypogonadism and anemia in an athlete.

We report the case of a highly trained endurance athlete (22-year-old) who developed anemia (Hb 9.5 mg/dl) over a period of 6 months. Iron deficient or haemolytic anemia, as well as chronic loss of blood, were excluded. Further, laboratory analyses revealed that this athlete exhibited very low levels of testosterone due to a partial hypogonadotropic hypogonadism. Following testosterone supplementation, red blood cell indices improved. Although hypogonadotropic hypogonadism is well known to be associated with reduced hematopoesis, it rarely causes anemia in athletes. This should be considered as a possible cause for anemia. Extreme training, unbalanced nutrition or the combination of both, have been shown to be causally involved in the development of secondary hypogonadotropic hypogonadism.

[Pulmonary embolism as a cause of a reduced performance capacity of endurance trained men - report of 2 cases]. / Lungenembolie als Ursache einer Leistungsminderung bei Ausdauersportlern - 2 Kasuistiken.

HISTORY AND ADMISSION FINDINGS: Two trained long-distance runners, aged 53 and 58 years, respectively, presented (independently) at our outpatient department because of an acute reduction in physical performance after considerable exertion. Neither had specific clinical symptoms, particularly no dyspnea. INVESTIGATIONS: Neither patient had abnormal findings on physical examination, such as signs for deep venous thrombosis. The electrocardiogram and echocardiography were normal. Exercise tests revealed a significant limitation in physical performance and, in one patient, a reduction in arterial blood oxygen and elevated d-dimers as the only abnormal laboratory test result. DIAGNOSIS, TREATMENT AND COURSE: The diagnosis of pulmonary embolism was made by computed tomography, which showed the typical changes. In both patients venous phlebography revealed deep vein thrombosis and signs of post-thrombotic changes. Laboratory tests were unremarkable, with normal blood coagulation and no factor II mutations. Anticoagulants were administered to each patient and they slowly resumed their training program. At a subsequent examination physical performance had improved, but there was still a reduction in arterial oxygen during exercise. CONCLUSION: Even endurance-trained sportspersons without thrombophilic risk factors may develop deep vein thrombosis. Even when there are no symptoms, pulmonary embolism should always be included in the differential diagnosis of a sudden and significant reduction in physical performance.

[Physical activity in pregnancy and in breast-feeding period in obese mothers]. / Bewegung in Schwangerschaft und Stillperiode bei mütterlichem Ubergewicht.

BACKGROUND: Regular physical activity is an important component of a health pregnancy. Being physically active during pregnancy often creates uncertainty and leads to numerous questions: How much and which kind of sports is possible? In pregnant woman a lot of physiological changes are taking place in haemodynamics, in the respiratory system, in the muculoskeletal system, in the glucose metabolism, and in further endocrinological feedback systems besides the psyche and bring about changes in fitness and physical performance. DISCUSSION: There is evidence that the most active women show the lowest prevalence for gestational diabetes (GDM) and, moreover a lower incidence for obesity and diabetes in both mother and child. Physically active women rarely develop not only GDM but also pre-eclampsia. The protective effect of physical activity can be explained by an enhanced placental growth and vascularity, by decreased oxidative stress, reduced inflammation and an adaption of the disease-related endothelial dysfunction. Maternal obesity increases the frequencies of infertility and miscarriage. Weight loss programmes with nutritional advice and activity counsellings represent a cost-effective infertility treatment. Moreover the possibility of health problems during pregnancy are limited thereby. A high degree of fitness before pregnancy and regular physical activity before conception can prevent the excessive weight gain during pregnancy and influence the weight at the very best. CONCLUSIONS: Considering common recommendations for training, as well as careful measures and contraindications, a moderate individual training to maintain physical and psychic fitness is desirable. Many kinds of sports like jogging, nordic walking, swimming and cycling, for example, can be carried out in a pregnancy without any risks and furthermore promote the health of the future mother and child.

The psychosocial situation of obese children: Psychological factors and quality of life.

The psychosocial situation of obese children at the beginning of the Freiburg Intervention Trial for Obese Children (FITOC) program influences the course and outcome of intervention therapy. At the beginning of FITOC, mothers of 30 children (12 ♂ age 10.5 ± 1.4, 18 ♀; 10.2 ± 1.3) rated the psychopathological symptoms using the Child Behavior Checklist (CBCL) and the quality of life of their children (Inventar zur Erfassung der Lebensqualität [ILK]). 46.6% of mothers rated their children to be disturbed (normal population group, 2% disturbed). There was no correlation between the body mass index of the child and the CBCL score. On the ILK, the obese children themselves selected "good" while the mother's view of their childrens' quality of life varied around "poor". The stress on the mother increased with the degree of the child's obesity and number of critical life events (p = 0.030). The CBCL and the ILK at the beginning of treatment serve as a good screening instrument for psychopathology and distress in children with obesity.

Motor abilities and aerobic fitness of obese children.

Obesity is considered to be epidemic worldwide. Stopping further progression interdisciplinary, outpatient intervention therapy programs for obese children have become increasingly important. FITOC (Freiburg Intervention Trial for Obese Children) consists of a combination of organized sports, behavioral therapy and nutritional advice. The effectiveness of the therapy is determined on the basis of anthropometrical and physical performance data. The purpose of this report is to give a differentiated view of the motor abilities of obese children and to describe changes in the course of the therapy program FITOC. Data were collected on n = 49 obese children (BMI > 97th percentile) aged 8 - 12 in a pretest at the beginning and posttest at the end of the intensive phase of the therapy. These data were compared with an age-matched German reference group. Besides the General Sports-Motor Test (Allgemeiner Sportmotorischer Test [AST]), the BMI-SDS values, the body fat mass (FM %) and the aerobic capacity (Watt/kg body weight) were recorded. In the pretest, the running exercise results and the aerobic capacity checked ranged significantly below the values of the reference group. The performance in the coordinative tests of the AST was differentiated. The medicine-ball toss was significantly above average of the reference group. In the posttest, the BMI-SDS values and the body fat mass (% FM) decreased (p < 0.001) and the aerobic capacity improved (p < 0.001). Performance in all motor abilities tests improved and the difference between the strength of the obese children and the strength of the reference group decreased. This study demonstrates that in obese children weight-bearing activities are below average but not all motor abilities.

External iliac artery occlusion in a young female cyclist.

After 8 years of high performance training in mountain biking, a top female athlete, aged 23, first complained of diffuse, exercise-induced pain in both thighs. Over a period of the next 4 years, a slight but continuous reduction in her performance was observed, despite having maintained her training regime during the first 2 years. Gradually, pain increased, at last occurring even when she climbed a few stairs. This led to a clinical, echo-Doppler, MR-angiographic and DS-angiographic examination, which showed a complete occlusion of the right iliac external artery with good collateralisation. The left external iliac artery evidenced only small intravascular lesions. Surgical treatment (endarterectomy plus patch angioplasty) eliminated the pain completely. Except for a lipoprotein (a) of 114 mg/dL, no other significant risk factors were found. The influence of a genetic (heterocygotic) low APC-ratio of 1.6 and free protein S of 53% is unclear. This is a typical case of a delayed diagnosis in an athlete. A complete occlusion of an external iliac artery is extremely seldom in young in female athletes. With no indication of a general atherosclerotic or inflammatory process nor congenital abnormalities, an exercise-induced, chronic traumatisation may have caused this pathological condition.

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.

[Freiburg intervention program for ambulatory therapy of obesity in childhood (FITOC)]. / Freiburger Interventionsprogramm zur ambulanten Therapie der Adipositas im Kindesalter (FITOC).

In this study we first try to answer the question, whether it is possible to make a successful treatment for obese children in an interdisciplinary program. Second it is asked whether a transfer of this program to further regions in Germany leads to comparable results. In FITOC children from the age of 8-11 years and over the 97. BMI-percentile are integrated in this program. The goals weight management, increased physical fitness and improvement of the cardiac risk profile are checked by weight, height, fasting blood serum, a standardized cycle ergometry and a medical measurement at the beginning, after treatment and at all check-ups. The recorded medical data show clearly that the intervention leads to a significant improvement in almost all checked parts. The successful treatment can be recorded after 8 months, likewise after 2.5 years as a long-term result. The further cornerstones of FITOC nutrition and psychology are not subject of this publication. In future the psychological part in FITOC will be evaluated by standardized inventories. The group from Düren has a success in therapy according to the definition of the program. Thereby it is shown that FITOC is extendable, if teams are trained intensively and the conditions are comparable. FITOC is able to treat obese children successfully over a long period of time. In consideration of the rising prevalence of obesity in childhood and the limited financial resources in health care this outpatient interdisciplinary program is an effective choice of treatment.

[The Freiburg Intervention Trial for Obesity in Chidren (FITOC)]. / Freiburger Interventionsprogramm zur ambulanten Therapie der Adipositas im Kindesalter (FITOC).

Freiburg Intervention Trial for Obese Children (FITOC) is an interdisciplinary treatment program for obese children, which is established in Freiburg since 1987. Obese children at the age of 8-11 are treated in an eight months intensive period and a follow-up period of 4 months or more. Since 1990 data from 283 children coming out of 15 treatment groups (about 2 groups per year) were collected and analyzed. The program consists of regular physical training (3 times a week), comprehensive nutrition and behaviour training (overall 7 parents evenings each 4 to 6 weeks and 7 cookery courses for the kids in the same time scale). The parents evenings are filled with theoretical and practical information about nutrition as well as background information about the psychological and physiological problems in obese children. In the first examination and the regular control examinations anthropometric, biochemical and exercise physiology data are investigated. In addition, questionnaires for nutrition and behaviour are analysed on a regular basis. At each examination, depending on the progress in therapy, a new orientation with adapted goals will be discussed with the child and the parents. For the growing children a moderate reduction or long term stabilisation of weight will lead to success. Teaching goal for the children in the intensive period is to control themselves and, depending on their specific situation, to establish individual recommendations on a long term basis. The sports program should lead to an increase in self-esteem and a raise in daily energy expenditure. The team includes a physician, a nutritionist, a psychologist and a sports teacher. From 1997 the program was spread to institutions in the surroundings of Freiburg. Training for the external teams is provided for in continuous seminars. Teaching material includes a manual, forms and transparencies. The major goal is to secure quality by continuous training and close interaction between the institutions. Till now the program is performed by a couple of multiplication groups in different regions of Germany. First data analysis has shown that the out-patient program is transferable and comparable results are reachable after a standardized training course for the included therapists. The plan for 2000 and 2001 is to increase the number of centers involved to a total of 20 all over Germany.

[Sports in the heart rehabilitation group--experiences with ambulatory rehabilitation at home]. / Sport in der Herzgruppe--Erfahrungen zur ambulanten kardialen Rehabilitation am Wohnort.

Regular physical exercise has shown to be beneficial for patients with cardiovascular disease. Therefore cardiac rehabilitation in Germany is continued for years after hospital discharge in outpatient cardiac exercise groups which meet twice a week under the guidance of a physician and a sports instructor. Before participation cardiac patients have to be examined including exercise tests and echocardiography for assessment of contraindications for exercise therapy as well as individual exercise capacity. Patients are assigned to two groups with different levels of exercise intensity according to their symptom-free work-capacity (cutoff level 1 W/kg). During exercise sessions sports-specific forms of exercise such as stretching, aerobic exercise or ball games are accompanied by psychosocial elements such as stress management. This global approach is intended to improve cardiovascular risk factors, cardiac function, and work capacity as well as to stabilize the patient psychologically in order to accelerate social integration. Recently these groups have opened towards patients after cardiac transplantation or with severe heart failure. Therefore, cardiac exercise groups play a central role in cardiac rehabilitation long after the acute cardiac event.

Sports and nutrition--an out-patient program for adipose children (long-term experience).

Sports activity (3 times per week), nutritional changes and modification of behavior are the basic tenets of an outpatient program run for 9- to 12-year-old adipose children since 1987. The following goals are to be attained: increase in physical performance capacity and body awareness, long-lasting change in eating habits, weight loss to under 20% overweight compared to the age-normal (height/normal weight), and understanding of the permanence of body weight problems. Individual nutritional consultation is offered in addition to the initial examination consisting of physical examination, skin fat-fold measurement, blood chemical parameters, spiroergometry and a detailed consultation with parents and children. The eating habits of the children are recorded in a dietary history (3-day dietary protocol, questionnaire) and discussed in individual meetings with the parents and children. Moreover, the nutritional program includes regular nutritional consultations and parents' meetings every month. Cooking instructions for children and parents provide practical knowledge of food preparation to preserve nutrients in an energy-reduced, tasty diet, as well as theoretical basics of nutrition. The control examinations show individual weight loss or stability and improvement in blood lipid parameters. Awareness and controlled nutritional habits were learned especially by the children of parents who, for their part, tried to tailor their nutrition to be better balanced, more nutritional and more need-oriented. Children who maintain the learned nutritional habits after completion of the outpatient program, and who remain active in sports, show long-lasting constant weight. Prevention must begin in childhood. Intensive nutritional support combined with an appropriate sports program should be offered as a preventive measure.

[Physical activity and eating behavior: strategies for improving the serum lipid profile of children and adolescents]. / Körperliche Aktivität und Essverhalten: Strategien zur Verbesserung des Serumlipidprofils bei Kindern und Jugendlichen.

Coronary risk factors such as obesity, dyslipoproteinaemia and low physical fitness are often prevalent in childhood. In contrast, regular physical activity and healthy nutrition have been shown to be effective in primary and secondary prevention of coronary artery disease. An increment in physical activity with concomitant weight loss has a profound influence on peripheral lipoprotein metabolism and has shown to improve the atherogenic lipoprotein profile. As risk factors often track from childhood into adulthood it seems inevitable to prevent or diminish risk factors as early as possible. Therefore, intervention programmes for prevention of coronary artery disease have to be conducted in childhood. Experience from an own intervention programme of obese children has shown that the combination of intensive dietary and physical education improves physical fitness, body composition as well as lipid metabolism. Whether short-term benefits will continue into adulthood and reduce coronary artery disease in midlife will have to be shown. Nonetheless, it seems out of question that children showing risk factors such as obesity or hypercholesterolaemia will benefit from early intervention programmes when changing dietary and exercise behaviours.

[Sports and nutrition--an ambulatory care program for obese children (long-term experiences)]. / Sport und Ernährung--ein ambulantes Programm für adipöse Kinder (Langzeiterfahrungen).

Sports activity (three times per week), dietary changes and modification of behavior are the basic tenets of an outpatient program run for 9- to 12-year-old adipose children since 1987. The following goals are to be attained: increase in physical performance capacity and body awareness, long-lasting change in eating habits, weight loss to less than 20% overweight compared to the age-normal, and understanding of the permanence of body weight problems. Individual dietary consultation is offered in addition to the initial examination consisting of physical examination, skin fat-fold measurement, blood chemical parameters, spiroergometry and a detailed discussion with parents and children. The eating habits of the children are recorded in a dietary history (three-day dietary protocol, questionnaire) and discussed in individual consultations with the parents and children. Moreover, the nutritional program includes regular nutritional consultations and parents' meetings every month. Cooking instructions provide practical knowledge of food preparation to preserve nutrients in an energy-reduced, tasty diet, as well as theoretical basics of nutrition. The control examinations show improvement in body-weight related performance capacity and laboratory parameters (lipid metabolism) as well as individual weight loss or stability (reference weight). Aware and controlled nutritional habits were learned especially by the children of parents who, for their part, tried to tailor their diets to be better balanced, whole-some and more need-oriented. Overall the nutritional composition improved with less energy intake. The intake of complex carbohydrates increased especially through consumption of ballast-rich müsli, as well as whole wheat bread, vegetables and fruits.(ABSTRACT TRUNCATED AT 250 WORDS)

Maximal steady state blood lactate levels in 11-year-old boys.

To evaluate whether anaerobic threshold criteria evaluated in adults are pertinent to children, ten boys with a mean age of 11.2 years were investigated during treadmill running. Maximal running velocity was determined at stepwise increasing load, with determination of blood lactate following exercise. On the following days four runs each lasting 16 min were performed at a constant speed starting with a speed corresponding to about 70% of the maximal speed and increasing it during the next run in order to determine maximal steady state levels of blood lactate. Blood lactate was measured at the end of every 4 min period. From this date the anaerobic threshold was calculated. The correlation between anaerobic threshold values and maximal steady state levels of blood lactate was poor, however, a steady state of blood lactate was present at 4.6 mmol/l, whereas the mean anaerobic threshold value was determined at 2.6 mmol/l. In view of our results, the anaerobic threshold during increasing work does not correspond to the true anaerobic threshold, which can be assumed to occur at much higher lactate values. The meaning of the term anaerobic threshold is therefore to be questioned.

[Sports and diet--an ambulatory program for obese children]. / Sport und Diät--ein ambulantes Programm für übergewichtige Kinder.

In an out-patient programme, 18 obese children aged 9-13 years were attended to for 1 year. The project consisted of an exercise programme performed 3 times per week, dietary restriction to 1200 kcal/d and psychological approach. The aim, besides weight reduction and acquisition of a healthy individual nutrition habit, was to improve physical performance and to increase self-confidence. All children improved physical and coordinative capacity and staying power and showed considerably more self-confidence. Weight reduction to a level below 20% overweight was achieved in the group of 12-13 years of age, whereas younger children showed minor weight loss. In the early period of treatment, HDL-cholesterol generally decreased but increased within 4-5 months exceeding pretreatment levels. No vitamin deficiencies occurred.

[Prevention and therapy of obesity with diet and sports, an ambulatory therapy program for overweight children]. / Prävention und Therapie von Adipositas durch Diät und Sport, ein ambulantes Therapieprogramm für übergewichtige Kinder.

Dietary restriction together with ongoing power-orientated training provide best results in the therapy and prevention of obesity. Diet can reduce the resting metabolic rate by up to 20% within 14 days. Physical activity stimulates the resting metabolic rate and counteracts this energy saving effect, but is especially important for maintaining a steady state after weight reduction. Exercise reduces the risk factors accompanying obesity by favorable adaptation of the sympathoadrenergic system to physical activity. This can be seen in the effects on heart rate, stroke volume, blood pressure, as well as glycogenolytic and lipolytic activities. Body fat especially in the abdominal area, which is particularly connected with atherogenic risk, is diminished. Weight reduction is accompanied by a decrease of the cardioprotective cholesterol fraction. Diets high in unsaturated fatty acids combined with a staying power training have a synergistic effect: they reduce a decrease of HDL. It is difficult to demonstrate risk factors connected with overweight children. However, from the preventive medicine point of view it is advisable to start with therapeutic measures during childhood. In an out-patient pilot project we surveyed 18 obese children aged 9 to 13 years. The therapy plan consisted of dietary restriction (1200 kcal/d), an exercise program performed 3 times a week, and psychological assistance. All children of 12 to 13 years arrived at an overweight level less than 20%, the younger ones displayed a lower weight reduction effect. All 18 improved their aerobic capacity. In the 1st months of treatment, HDL-cholesterol decreased slightly, but increased above pre-treatment level, later on. We did not see any vitamin deficiencies during the therapeutic regimen.

[Plasma catecholamines, metabolic substrates, aerobic and anaerobic capacity during exercise in supine and sitting position (author's transl)]. / Einfluss der Ergometerarbeit im Liegen und Sitzen auf Plasmacatecholamine, metabolische Substrate sowie Sauerstoffaufnahme und Herzfrequenz.

The influence of a graduated bicycle ergometric test in supine and sitting position on the work capacity, the plasma catecholamines, the carbohydrate (glucose and lactate) and lipid metabolism (free fatty acids and glycerol) and the heart rate and oxygen intake was examined in six healthy subjects. The work capacity is approx. 30% higher in sitting position. In supine position, adrenaline and nor-adrenaline are lower at rest, at all submaximum levels and during maximum ergometric exercise. Glucose, free fatty acids and glycerol show no differences dependent on the body position at the same submaximum levels, only the lactate level is approx. 30% higher (200 Watt) in supine position. During maximum graduated exercise in sitting position the glucose level is 10% higher than in supine position, the free fatty acids show no difference; the lactate level is approx. 37% higher, the glycerol level approx. 40% than in supine position. The heart rate and the oxygen intake don't show any position dependent differences at rest and at the same submaximum levels. During maximum ergometric exercise they are 15% (heart rate) and about 30% (oxygen intake) higher than in supine position, corresponding to a higher exercise level.

[The influence of graduated treadmill exercise on plasma catecholamines, aerobic and anaerobic capacity in boys and adults]. / Einfluss einer stufenweisen Laufbandergometrie bei Kindern und Erwachsenen auf die Plasmacatecholamime, die aerobe und anaerobe kapazität.

Adrenaline, noradrenaline, lactate and glucose levels in the blood, together with the heart rate and oxygen intake were examined in eight boys (12.8 +/- 0.8 years) and seven adults (27.8 +/- 2.9 years) during a graduated treadmill exercise. At rest, noradrenaline is higher in the adults, while adrenaline, lactate, glucose, heart rate and relative oxygen intake show no differences between the groups. At the same exercise levels, adrenaline (+ 90-180%), noradrenaline (+ 28-77%) and the heart rate are higher in boys, corresponding to a higher relative exercise load, and glucose, lactate and the relative oxygen intake show no differences. During maximum treadmill exercise adrenaline, glucose and the relative oxygen intake show no differences between the groups, whereas the noradrenaline (-30%) and lactate levels (-25%) are lower and the heart rate is 4% higher in the boys. There is an identical increase in lactate and catecholamine levels (r = 0.92 and 0.87) with a lower correlation with high intensity "anaerobic" physical exercise, which shows no age dependent difference until about the age of 40. The maximum catecholamine (adrenaline and noradrenaline) and lactate concentration is 25% lower in the boys; an indication of reduced maximum sympathetic activity and reduced maximum anaerobic capacity is seen. The constant relationship between adrenaline and noradrenaline during physical work (r=0.90 and 0.85), also with a lower correlation at high intensive physical exercise, changes from 1 : 3.5 (boys) to 1 : 5.5 (adults) (p less than 0.001), based on higher noradrenaline levels in the adults at rest, at submaximum exercise levels and during maximum ergometric work; these changes are seen to be the cause of an age dependent negative chronotropic effect.