Endurance and resistance training in patients with acute leukemia undergoing induction chemotherapy-a randomized pilot study.

PURPOSE: Acute leukemia (AL) and its initial treatment can impair physical functioning and capacity significantly. Exercise as a countermeasure has been investigated in few studies confirming its feasibility and safety during intensive induction chemotherapy, but the relative effects of diverse exercise programs have not been analyzed. Therefore, we aimed to investigate independent effects of endurance and resistance training on physical capacity and quality of life (QOL). METHODS: Twenty-nine adult AL patients were randomly allocated to an endurance (EG), resistance (RG), or control (CG) group. The intervention took place during induction chemotherapy with three exercise sessions per week for 30-45 min each. Endurance capacity at individual anaerobic threshold, maximum knee extension and flexion strength, standardized phase angle (SPA), and QOL were measured at baseline prior to induction chemotherapy and before discharge. RESULTS: Endurance capacity changed in neither the EG, RG, or CG (P = 0.104); descriptively, the EG (- 0.05 W/kg) and RG (- 0.04 W/kg) exhibited a smaller decrease than CG (- 0.22 W/kg). We noted a significant difference in knee extension strength (P = 0.002); RG improved their maximum strength (+ 0.14 Nm/kg), while the EG's (- 0.13 Nm/kg) and CG's (- 0.19 Nm/kg) was significantly reduced. QOL and SPA revealed no change after the intervention. CONCLUSIONS: We conclude that resistance training is a key component when exercising during induction chemotherapy: it improved maximum strength, but also influenced endurance capacity even during intensive treatment. Considering the prognostic value of physical function, we strongly propose integrating exercise, especially resistance-based training, already during induction chemotherapy to preserve AL patients' physical capacity and functional status.

Prognostic value of Achilles tendon Doppler sonography in asymptomatic runners.

INTRODUCTION: Midportion Achilles tendinopathy (MPT) is a common problem in running athletes. Nevertheless, its etiology is not fully understood, and no valid prognostic criterion to predict the development of MPT could be identified to date. The purpose of the present study, therefore, was to evaluate whether power Doppler ultrasonography (PDU) is a suitable method to identify a predisposition to MPT in yet asymptomatic runners. METHODS: At 23 major running events, 634 asymptomatic long-distance runners were tested for Achilles tendon thickness, vascularization, and structural abnormalities using a high-resolution PDU device (Toshiba Aplio SSA-770A/80, 12 MHz). In addition, their medical history and anthropometric data were documented. All subjects were contacted 6 and 12 months later and asked about any new symptoms. The collected anamnestic, anthropometric, and ultrasonographic data were subjected to regression analysis to determine their predictive value concerning the manifestation of midportion Achilles tendon complaints (P < 0.05). RESULTS: The highest odds ratio (OR) for manifestation of MPT within 1 yr was found for intratendinous blood flow ("neovascularization," OR = 6.9, P < 0.001). An increased risk was also identified for subjects with a positive history of Achilles tendon complaints (OR = 3.8, P < 0.001). A third relevant parameter, just above the level of significance, was a spindle-shaped thickening of the tendon on PDU (Wald χ2 = 3.42). CONCLUSIONS: PDU detection of intratendinous microvessels in the Achilles tendons of healthy runners seems to be a prognostically relevant factor concerning the manifestation of symptomatic MPT. This finding lays the foundation for an early identification of a predisposition to MPT as well as prophylactic intervention in as yet asymptomatic runners.

Soy protein based supplementation supports metabolic effects of resistance training in previously untrained middle aged males.

OBJECTIVE: To determine changes in body composition, physical performance, metabolic and hormonal parameters induced by lifestyle counselling, resistance training and resistance training with soy protein based supplemention in middle aged males. DESIGN: Randomised controlled study consisting of resistance training without (RT-G) or with (RTS-G) a soy protein based supplement and a control group with lifestyle education only (LE-G). SUBJECTS: Forty healthy middle aged men (50-65 years, BMI 25-29.9 kg/m2). MEASUREMENTS: Changes in body weight (BW) and waist circumference (WC) were measured and body composition (BC), fat mass (FM), lean body mass (LBM) were measured by skin fold anthropometry at baseline and after 12 weeks of intervention. In addition, changes in physical fitness, metabolic and hormonal parameters (lipids, glucose, fructosamines, insulin, insulin-like growth factor-1, Leptin, human growth hormone, dehydroepiandrosterone, testosterone, hs-CRP, Il-6) were evaluated. RESULTS: Thirty-five participants completed the 12 week study. No significant changes in BW were noted although RM and WC dropped and LBM increased after training, particularly in the RTS group (FM 22.6 ± 5.5 kg to 21.2 ± 4.7 kg; LBM 68.5 ± 7.2 kg to 70.1 ± 7.4; p < 0.01). Subjects in the RTS group experienced more pronounced improvements in the strength measurements than the RT group. After the training intervention there were significant changes in hormonal and metabolic parameters as well as in glycemic control, particularly in the RTS group. CONCLUSIONS: Our data suggest that resistance training, particularly in combination with a soy protein based supplement improves body composition and metabolic function in middle aged untrained and moderately overweight males.

[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.

Effect of a supplement rich in alkaline minerals on acid-base balance in humans.

BACKGROUND: Western diets are considered acidogenic due to the high dietary acid load and a low intake of base-forming dietary minerals such as potassium, magnesium or calcium. In the present study we investigated the effect of a multimineral supplement (MMS) rich in alkaline minerals on acute and chronic regulation of acid-base balance with the pH of blood, urine and saliva as potential surrogate markers. METHODS: Parameters were measured (i) without MMS intake, (ii) in the three consecutive hours following ingestion (blood and urinary pH) and (iii) during one week with or without MMS intake (self-monitored using pH measurement strips). RESULTS: 25 (15 female; 10 male) subjects (age 44 +/- 14 y; BMI 23.9 +/- 1.9 kg/m2) were enrolled in the investigation. Following acute administration of the MMS in the morning, blood ph (1 and 2 h after ingestion) rose from 7.40 to 7.41; p < 0.05, and also urinary pH 3 h after ingestion (5.94 to 6.57; p < 0.05) increased significantly. Following longer-term supplementation, both the increase in urinary pH in the morning and in the evening occurred within 1 day. Compared to pH values without the MMS, average pH in urine was 11% higher in the morning and 5% higher in the evening. Analyses of food records showed that the increase in urinary pH was not related to dietary change. CONCLUSION: Our results suggest that the ingestion of a multimineral supplement is associated with both a significant increase in blood and urinary pH. The health related consequences of this supplementation remain to be determined.

Hemoglobin mass after 21 days of conventional altitude training at 1816 m.

The underlying mechanisms of altitude training are still a matter of controversial discussion but erythropoietic adaptations with an increase of total haemoglobin mass (tHb) have been shown in several studies, partly depending on an adequate hypoxic dose. The aim of this retrospective study was to investigate if a 3 weeks sojourn at moderate altitude (1816 m) with conventional training sessions (live and train at moderate altitude), especially under real and uncontrolled conditions, results in an increased tHb. tHb was measured in seven male cyclists competing at elite level (German national cycling team, U23 category) prior to the ascent to altitude and immediately after descent to sea-level. The athletes completed a 21 days altitude training camp living at 1816 m and training at 1800-2400 m during the competitive season. No significant difference was found in tHb after the altitude sojourn (prior 927+/-109g vs. 951+/-113g post, 95% CI -13-61g). Additionally, the analysis of red cell volume, plasma volume and blood volume or haemoglobin concentration [Hb] as well as haematocrit (Hct) did not reveal any significant changes. The data supports the theory that an adequate hypoxic dose is required for adaptations of the erythropoietic system with an increase of tHb and a threshold of approximately 2100-2500 m has to be exceeded.

Recovery of hemoglobin mass after blood donation.

BACKGROUND: Blood donation plays an important role in every health care system. Measurement of hemoglobin (Hb) concentration or hematocrit to assess hematologic recovery after donation may not adequately reflect the true amount of blood as they are affected by plasma volume fluctuations. Instead, total Hb mass (tHb) is the variable of choice and can be determined in routine clinical practice. Therefore, the purpose was to investigate the recovery of tHb after standard blood donation. STUDY DESIGN AND METHODS: The optimized CO rebreathing method was used for evaluation of tHb before and after 1-unit (erythrocyte concentrate) standard blood donation in 29 male volunteers (30 +/- 10 years, 181 +/- 7 cm, 76.6 +/- 11.2 kg). Subsequently, tHb measurements were performed in regular intervals until one of two termination criteria was met. RESULTS: After donation of approximately 550 mL of whole blood, the lost amount of tHb of 75 +/- 15 g (8.8 +/- 1.9%) was recovered after a mean of 36 +/- 11 days (range, 20-59 days). CONCLUSIONS: The results of this study confirm the minimal, recommended donation intervals (56 days for men) as adequate when, for the first time, judged upon by tHb as a direct marker of hematologic recovery.

Unusual cause of exercise-induced ventricular fibrillation in a well-trained adult endurance athlete: a case report.

INTRODUCTION: The diseases responsible for sudden deaths in athletes differ considerably with regard to age. In young athletes, congenital malformations of the heart and/or vascular system cause the majority of deaths and can only be detected noninvasively by complex diagnostics. In contrast, in older athletes who die suddenly, atherosclerotic disease of the coronary arteries is mostly found. Reports of congenital coronary anomalies as a cause of sudden death in older athletes are rare. CASE PRESENTATION: A 48-year-old man who was a well-trained, long-distance runner collapsed at the finish of a half marathon because of a myocardial infarction with ventricular fibrillation. Coronary angiography showed an anomalous origin of the right coronary artery from the left sinus of Valsalva with minimal wall alterations. Multislice computed tomography of the coronary arteries confirmed these findings. Cardiomagnetic resonance imaging demonstrated a mild hypokinesia of the basal right- and left-ventricular posterior wall. An electrophysiological study showed an inducible temporary polymorphic ventricular tachycardia and an inducible ventricular fibrillation. The athlete was subsequently treated by acetylsalicylic acid 100 mg (0-1-0), bisoprolol 2.5 mg (1-0-0) and atorvastatin 10 mg (0-0-1) and was instructed to keep his training intensity under the 'individual anaerobic threshold'. Intense and long-lasting exercise under extreme environmental conditions, particularly heat, should also be avoided. CONCLUSION: This case report presents a coronary anomaly as the most likely reason for an exercise-induced myocardial infarction with ventricular fibrillation in a well-trained 48-year-old endurance athlete. Therefore, coronary anomalies have also to be considered as a possible cause of cardiac problems in older athletes.

Influence of physiologic cardiac hypertrophy on the prevalence of heart valve regurgitation.

OBJECTIVE: Chronic dynamic exercise leads to regulative and structural adaptations of the heart (athlete's heart). To what extent the enlargement and physiologic hypertrophy of the heart lead to changes in the function of the valves, particularly regurgitation, is not yet clear. The aim of this study was to examine the regurgitation levels of different states of "athlete's heart." METHODS: Our study population consisted of 5124 healthy subjects (4046 male and 1078 female, 18-60 years), regularly exercising 1 to 20 h/wk. Subjects were divided into 3 groups depending on their relative heart volumes (RHVs): (1) very enlarged heart group (VEHG; male, n = 1251; female, n = 201), with RHVs of greater than 14 (male) and 13 (female) mL/kg; (2) mildly enlarged heart group (MEHG; male, n = 702; female, n = 224), with RHVs of 12 to 14 (male) and 11 to 13 (female) mL/kg; and (3) control subjects (CS; male, n = 2093; female, n = 653), with RHVs of less than 12 (male) and 11 (female) mL/kg. RESULTS: According to US Food and Drug Administration criteria for valve regurgitation, it could be shown by Doppler sonography that as physiologic enlargement and hypertrophy increased significantly, the frequency and severity of aortic valve regurgitation (mean +/- SD: VEHG, 0.04 +/- 0.09; MEHG, 0.09 +/- 0.10; CS, 0.10 +/- 0.11; P < .05) and high mitral regurgitation (VEHG, 0.10 +/- 0.17; MEHG, 0.20 +/- 0.29; CS, 0.26 +/- 0.32; P < .01) decreased. On the contrary, pulmonary regurgitation (VEHG, 0.79 +/- 0.45; MEHG, 0.47 +/- 0.33; CS, 0.35 +/- 0.38; P < .01) and tricuspid valve regurgitation (VEHG, 0.42 +/- 0.29; MEHG, 0.47 +/- 0.33; CS, 0.35 +/- 0.38; P < .01) increased highly significantly with heart size. CONCLUSIONS: These findings strongly support the view of athlete's heart as a physiologic adaptation of the heart, at least on the left side, not causing increased valvular regurgitation.

[An unusual cause of recurrent chest pain in a highly trained recreational athlete]. / Ungewöhnliche Ursache rezidivierender AP-Beschwerden bei einem Ausdauersportler.

ANAMNESIS: Here, the case of a 48-year-old highly trained patient without classic myocardial risk factors is described who reported on frequent and recurrent angina pectoris. In a previous examination, the test for cardiac troponin T (cTnT) was slightly positive, however, cardiac examination including myocardial perfusion scintigraphy and coronary catheterization was without pathologic findings. Worth mentioning in the past medical history was a rheumatoid arthritis with persistent Raynaud's symptoms and hemoglobin as well as hematocrit levels in the upper normal range. EXAMINATIONS AND COURSE OF EVENTS: The patient reported that symptoms would occur most likely during long-term endurance exercise. Therefore, a bicycle ergometry with 180 W and open ending was performed. After 1.55 h, the patient complained of severe angina pectoris. The ECG showed massive ST segment elevations in II, III, and aVF (Figure 2). However, coronary catheterization showed no major stenosis or occlusion. Nevertheless, cTnT increased to 0.979 ng/ml. (Therefore, the reason for the symptomatic ST elevation was believed to be a myocardial tissue damage due to coronary vasospasm and the patient received an antivasospastic medication (amlodipine, atorvastatin, and acetylsalicylic acid [ASS]). After 6 months, the patient had a relapse during moderate physical activity. The ECG showed an ST segment depression in V(4) and V(5) while markers for myocardial tissue damage including cTnT were negative. A coronary CT angiography was performed that revealed a subtotal stenosis of the proximal LAD (Fig ure 3), which was successfully treated by angioplasty with subsequent stenting. In the course of further examinations, a polycythemia vera (JAK2-V617 mutation) was diagnosed as the cause for the high hemoglobin and hematocrit levels. Since then, the patient was without further events under a medication consisting of ASS, atorvastatin, candesartan, and intermittent phlebotomy. CONCLUSION: Although a relative weighting is difficult, it can be assumed that the combined effects of a polycythemia- associated hypercoagulability, an increased reagibility of the coronary arteries (aggravated by physical stress) as well as a hemoconcentration following prolonged exercise, could account for symptomatic recurrent minor thrombotic coronary events as well as the subtotal occlusion of the LAD. Obviously, this could not be prevented by a healthy lifestyle, regular physical activity, and the absence of classic coronary risk factors.

Cycling power output produced during flat and mountain stages in the Giro d'Italia: a case study.

Until recently, the physiological demands of cycling competitions were mostly reflected by the measurement of heart rate and the indirect estimation of exercise intensity. The purpose of this case study was to illustrate the varying power output of a professional cyclist during flat and mountain stages of a Grand Tour (Giro d'Italia). Nine stage recordings of a cyclist of the 2005 Giro d'Italia were monitored using a mobile power measurement device (SRM Trainingssystem, Julich, Germany), which recorded direct power output and heart rate. Stages were categorized into flat (n = 5) and mountain stages (n = 4). Data were processed electronically, and the overall mean power in flat and mountain stages and maximal mean power for various durations were calculated. Mean power output was 132 W +/- 26 (2.0 W x kg(-1) +/- 0.4) for the flat and 235 W +/- 10 (3.5 W x kg(-1) +/- 0.1) for the mountain stages. Mountain stages showed higher maximal mean power (367 W) for longer durations (1800 s) than flat stages (239 W). Flat stages are characterized by a large variability of power output with short bursts of high power and long periods with reduced intensity of exercise, whereas mountain stages mostly require submaximal, constant power output over longer periods.

[Cardiovascular preparticipation screening of competitive athletes]. / Die kardiovaskuläre Voruntersuchung im Wettkampfsport.

Cardiovascular deaths during or following sport activities repeatedly raise the question about a practicable preparticipation screening for athletes to prevent such adverse events. In Germany and most European countries, well-equipped sports medicine centers evaluate the health of the Olympic athletes through regular checkups, which include a detailed medical history and thorough physical examination as well as an ECG at rest, a stress ECG, and an echocardiography. In professional sports, guidelines for this screening differ according to the federations, however, most of them intend to follow the recommendations of the Olympic sports system. For nonprofessional competitive sports, there are no guidelines for preparticipation screening, although these athletes train at the same level of intensity as professional athletes. The main issue in this international debate is the question of cost-effectiveness and how to finance preventive measures.

Power output during stage racing in professional road cycling.

PURPOSE: The aim of the study was to evaluate the power output during a multistage professional road race using direct power measurements and to compare these results with the performance measurements using competition heart rate recordings. METHODS: Six professional road cyclists performed an incremental cycling test during which peak power output, power output, and heart rate at the lactate threshold (LT) and at a lactate increase of 1 mM above the LT (LT + 1) were assessed. During a six-stage road race competition, power output was measured directly (SRM crankset). To analyze the time spent at different intensities during competition, the amount of competition time spent below LT (zone 1), between the LT and LT + 1 (zone 2), and above LT + 1 (zone 3) determined during laboratory testing were calculated for power output and heart rate. RESULTS: During the five mass start stages, a mean power output of 220 +/- 22 W (3.1 +/- 0.2 W x kg(-1)) with a mean heart rate of 142 +/- 5 bpm was measured. Average power output during an uphill time trial was 392 +/- 60 W (5.5 +/- 0.4 W x kg(-1)) with a mean heart rate of 169 +/- 3 bpm. For the mass start stages, the average distribution of exercise time spent in different intensities calculated for power output and heart rate was 58 versus 38% for zone 1, 14 versus 38% for zone 2, and 28 versus 24% for zone 3. CONCLUSION: Most of the competition time during the mass start stages was spent at intensities near the LT. Compared with power output, heart rate measurement underestimated the time spent at intensity zones 1 and 3, and overestimated the time spent in zone 2.

Anabolic ergogenic substance users in fitness-sports: a distinct group supported by the health care system.

BACKGROUND: Anabolic ergogenic substance use, in particular the use of anabolic androgenic steroids, is a serious problem in general. Nevertheless, it is subject to debate whether ergogenic substance users exhibit similar features as multiple substance users or whether they constitute a discrete group. METHODS: One thousand eight hundred and two standardized, anonymous questionnaires were distributed among visitors of 113 fitness centers. Questions were asked concerning biometric parameters, social indicators, physical fitness, use of natural stimulants, general illicit drugs and ergogenic substances. With logistic regression analysis, multivariate odds ratios were estimated to investigate the association of anabolic ergogenic substance or general illicit drug use with other parameters. RESULTS: 13.5% of all participants confessed to having used anabolic ergogenic substances at some point in time. Anabolic ergogenic substance use was positively related with cocaine use, training years, training frequency, negatively related to the level of education, alcohol intake and less frequently used by Germans than by non-Germans. General illicit drug use, however, was positively related with alcohol intake, smoking and a university degree and negatively with having children. In addition, anabolic ergogenic substance use was significantly related with the use of general illicit drugs based on the strong relation with the use of cocaine, which is an ergogenic substance itself. The health care system supplies 48.1% of the anaolic ergogenic substance users with their substances and 32.1% are even monitored by a physician. CONCLUSIONS: The results of this study strengthen the notion that anabolic ergogenic substance users constitute a specific body-oriented substance user group. Uncommon for general illicit drug use, the health care system is a major sponsor of anabolic ergogenic substance users. These findings suggest the need for alternative approaches for successful prevention and intervention programs.

[Endurance training and cardial adaptation (athlete's heart)]. / Ausdauersport und kardiale Adaptation (Sportherz).

One essential function of the cardiovascular system is to provide an adequate blood supply to all organs, including the skeletal muscles at rest and during exercise. Adaptation to chronic exercise proceeds mainly via the autonomic nervous system. On the one hand, peripheral muscles influence the autonomic reactions through "feedback" control via ergoreceptors, in particular, mechano- and chemoreceptors. On the other hand, there is central control in the sense of a "feed forward" regulation, e. g., the reaction of an athlete before competition. Along with other influential factors, such as circulatory presso-, chemo-, and volume receptors, the incoming impulses are processed in vegetative centers.A cardiovascular reaction, then, is the result of nerval and humoral sympathetic and parasympathetic activity. At rest, the parasympathetic tone dominates. It reduces heart frequency and conduction velocity. The high vagal tone is initially reduced with increasing physical exertion and switches at higher intensity to increasingly sympathetic activation. This mechanism of reaction to exercise is supported by inverse central and peripheral transmissions.Chronic endurance training leads to an improved local aerobic capacity of the exercised musculature. At rest, it augments parasympathetic activity when the muscle mass is sufficiently large, i. e., 20-30% of the skeletal musculature. The extent of the adaptation depends on individual factors, such as scope, intensity of training, and type of muscle fiber. A higher vagal tone delays the increase in the sympathetic tone during physical exertion. The regulatory range of heart rate, contractility, diastolic function, and blood pressure is increased. In addition, adaptation results in functional and structural changes in the vascular system. Cardiocirculatory work is economized, and maximum performance and oxygen uptake are improved. Endurance training exceeding an individual limit causes harmonic enlargement and hypertrophy of the heart. The thickness of both, the septum and posterior wall increases to the same extent as the interior volume. The mass/volume ratio, and therefore the maximum systolic wall stress, remains constant in contrast to pathologic forms of hypertrophy. Adaptations, including function and size of the heart, show a regression in healthy inactive persons without any structural heart disease.

Myocardial stress after competitive exercise in professional road cyclists.

PURPOSE: Based on the determination of cardiac troponin (cTnT), brain natriuretic peptide (BNP), and echocardiographic measurements, recent investigations have reported myocardial damage and reversible cardiac dysfunction after prolonged endurance exercise in apparently healthy subjects. In the present study, we investigated the myocardial stress reaction in professional endurance athletes after strenuous competitive physical exercise. METHODS: Eleven highly trained male professional road cyclists (age 27 +/- 4 yr; .VO2peak 67 +/- 5 mL.kg-1.min-1; training workload 34,000 +/- 2,500 km.yr-1) were examined. The following parameters were determined before and after one stage of a 5-d professional cycling race: BNP, cTnT (third-generation assay that shows no cross reactivity with skeletal TnT), creatine kinase (CK), creatine kinase MB (CKMB), myoglobin (Myo), and urea. All participants were submitted to a careful cardiac examination including echocardiography and stress ECG. RESULTS: None of the athletes showed pathological findings in the cardiac examination. CK (P < 0.01), CKMB (P < 0.05), and Myo (P < 0.01) were increased after the race. Normal postexercise cTnT levels indicate that the increase in CK, CKMB, and Myo was of noncardiac origin. In contrast, BNP rose significantly from 47.5 +/- 37.5 to 75.3 +/- 55.3 pg.mL-1 (P < 0.01). Pre- and postexercise values of BNP as well as the individual exercise-induced increase in BNP were significantly correlated with age (R2 = 0.68, R2 = 0.66, and R2 = 0.58, respectively; P < 0.05). CONCLUSION: Strenuous endurance exercise in professional road cyclists does not result in structural myocardial damage. The rise in BNP in older athletes may reflect a reversible, mainly diastolic left ventricular dysfunction. This needs to be confirmed by larger trials including different intensities, sports, and age groups.

Evaluation of stress responses to interval training at low and moderate altitudes.

PURPOSE: The purpose of the present field study was to explore whether extensive interval training (IT) performed with a similar behavior of blood lactate (LA) at an altitude of 1800 m (ALT) and near sea level (SL) goes along with a comparable hormonal, metabolic, and acute phase response in highly trained endurance athletes. METHODS: Twelve distance runners (VO2 64.6 +/- 6.9 mL.kg(-1) ) performed IT (10 x 1000 m, 2-min rest) at SL with a running velocity (V) corresponding to 112% of the individual anaerobic threshold (IAT). After an acclimatization period of 7 d, IT was repeated with a lower V (107% IAT) at ALT. Blood samples were drawn at rest, 0, 0.3, 3, and 24 h after IT. LA during IT was similar at SL and ALT (5.4 +/- 1.3/5.3 +/- 1.2 mmol.L(-1)), whereas HR tended to be higher at SL. RESULTS: Postexercise rises in plasma noradrenaline (NA), NA sulfate, adrenaline, glucose, interleukin-6 (IL-6), and neutrophils were significantly more pronounced at ALT. The increase of cortisol and human growth hormone showed an insignificant trend toward higher values at ALT. A slight but significant increase of plasma erythropoietin was only apparent after IT at ALT. No differences between either condition were observed for exercise-related changes in free fatty acids, IL-8, lympho-, or monocyte counts. CONCLUSIONS: In spite of a matched accumulation pattern of LA between ALT and N, stress responses, such as sympathetic activation and hepatic glucose release, still appear to be greater at ALT. This additional impact of moderate ALT on the stress response to IT should be taken into account if repeated training sessions are performed within a short period of time.

Heart rate prescriptions from performance and anthropometrical characteristics.

PURPOSE: Heart rate (HR) is widely used to adjust exercise intensity in aerobic training. Training HR recommendations are calculated often from simple equations. Because at lactate steady state (LASS) may be an intensity of exercise eliciting similar objective measures of intensity and similar subjective measures of metabolism, it is an appropriate intensity upon which to base aerobic-training prescription. The purpose of this research was to develop regression equations using age and other easily accessible characteristics to estimate the HR associated with LASS (HRLASS). METHODS: The data of 7397 healthy subjects (age >or= 10 yr; 5044 male, 2353 female) with different training habits were analyzed. All participants were tested in an incremental exercise test on the treadmill until subjective exhaustion. The LASS was determined by the concept of blood lactate at the "lactate threshold" plus a net increase of 1.5 mmol.L-1. The interdependence of further characteristics was tested by stepwise multiple regression. RESULTS: Age alone did not allow a precise prediction of lass=hText>HRLASS (r = 0.645 for all participants), regardless of adjustment by sex, training state, body mass, or performance characteristics using ANCOVA. Resting HR (HRrest) decreased steeply within the second life decade but not with further advancing age. The best discrete lactate-independent predictor for HRLASS was HRmax (r = 0.798). Inclusion of age and weight in the model resulted in only a small improvement of the prediction (r = 0.826). Other anthropometrical characteristics could not improve the model further. CONCLUSIONS: The use of age alone seems too imprecise for exactly driven aerobic training prescriptions. A minor improvement can be achieved in this objective by use of HRmax supplemented by age using a multiple regression model.