Paul Haber

Effects of physical training on heart rate variability in diabetic patients with various degrees of cardiovascular autonomic neuropathy

OBJECTIVE To investigate the effects of regularly performed endurance training on heart rate variability in diabetic patients with different degrees of cardiovascular autonomic neuropathy (CAN). METHODS Bicycle ergometer training (12 weeks, 2 x 30 min/week, with 65% of maximal performance) was performed by 22 insulin-requiring diabetic patients (age 49.5 +/- 8.7 years; diabetes duration 18.6 +/- 10.6 years; BMI 25.1 +/- 3.4 kg/m2): i.e., by 8 subjects with no CAN, 8 with early CAN and by 6 patients with definite/severe CAN. A standard battery of cardiovascular reflex tests was used for grading of CAN, a short-term spectral analysis of heart rate variability for follow-up monitoring of training-induced effects. RESULTS While the training-free interval induced no changes in spectral indices, the 12-week training period increased the cumulative spectral power of the total frequency band (P = 0.04) but to a different extent (P = 0.039) in different degrees of neuropathy. In patients with no CAN the spectral power in the high-frequency (HF) band (0.15-0.50 Hz) increased from 6.2 +/- 0.3 to 6.6 +/- 0.4 In [ms2]; P = 0.016, and in the low-frequency (LF) band (0.06-0.13 Hz) from 7.1 +/- 0.1 to 7.6 +/- 0.3 in [ms2]; P = 0.08 which resulted in an increase of total spectral power (0.06-0.50 Hz) from 7.5 +/- 0.1 to 8.0 +/- 0.3 in [ms2] (P = 0.05). Patients with the early form of CAN showed an increase of spectral power in HF (5.1 +/- 0.2 to 5.8 +/- 0.1 in [ms2], P = 0.05) and LF bands (5.6 +/- 0.1 to 6.3 +/- 0.1 in [ms2], P = 0.008), resulting in an increase of total power from 6.1 +/- 0.1 to 6.6 +/- 0.1 in [ms2] (P = 0.04), whereas those with definite/severe CAN showed no changes after the training period. Training improved fitness in the whole patient cohort. The increased autonomic tone as assessed by spectral indices disappeared after a training withdrawal period of 6 weeks. CONCLUSIONS In diabetic patients with no or early CAN, regularly performed endurance training increased heart rate variability due to improved sympathetic and parasympathetic supply, whereas in subjects with definite/severe CAN no effect on heart rate variability could be demonstrated after this kind of training.

Strength and endurance training lead to different post exercise glucose profiles in diabetic participants using a continuous subcutaneous glucose monitoring system

Background  Although both strength training (ST) and endurance training (ET) seem to be beneficial in type 2 diabetes mellitus (T2D), little is known about post‐exercise glucose profiles. The objective of the study was to report changes in blood glucose (BG) values after a 4‐month ET and ST programme now that a device for continuous glucose monitoring has become available.

Efficacy of systematic endurance and resistance training on muscle strength and endurance performance in elderly adults – a randomized controlled trial

ZusammenfassungHINTERGRUND: Im Alter kommt es sowohl zu einer Reduktion der Muskelmasse als auch zu metabolischen Veränderungen im Skelettmuskel. Ein Großteil dieser Veränderungen ist auf Bewegungsmangel zurückzuführen und kann durch ein Ausdauertraining (ET) und Krafttraining (RT) verhindert werden. FRAGESTELLUNG: Welche Trainingsmethode ist die effektivste, um die physische Leistungsfähigkeit im Alter zu verbessern? Das Ziel dieser Studie ist es festzustellen, ob ein systematisches ET auch die Muskelkraft steigern kann und/oder ob ein systematisches RT auch die aerobe Kapazität von gesunden alten Menschen verbessern kann. UNTERSUCHUNGEN/METHODEN: 42 Probanden (32 Frauen, 10 Männer) wurden für die Studie rekrutiert und in 3 Gruppen randomisiert: 13 Probanden führten ein 6-monatiges ET Programm durch, 15 Probanden ein 6-monatiges RT Programm und 14 Probanden wurden in die Kontrollgruppe gelost. Eine Belastungsspiroergometrie und eine Dynamometrie wurden zu Beginn und am Ende der Studie absolviert, um die aerobe Kapazität (VO2max), die maximale Leistungsfähigkeit (Wmax), sowie die Maximalkraft (1-RM) zu testen. ERGEBNISSE: Die Maximalkraft verbesserte sich signifikant (zwischen 15% und 30%) nach 6 Monaten RT, während ET zu keiner signifikanten Veränderung der Maximalkraft führte. ET resultierte in einer hoch signifikanten Verbesserung der Wmax um 31%, während RT nur eine moderate Verbesserung der Wmax um 6% zeigte. ET resultierte zusätzlich in einer signifikanten Reduktion des Körperfettanteils, RT in einer Zunahme der fettfreien Magermasse. SCHLUSSFOLGERUNG: Sowohl ET, als auch RT wirken positiv auf die Gesundheit und Fitness gesunder alter Menschen, jedoch auf unterschiedliche Art und Weise: ET verbessert die aerobe Kapazität, jedoch nicht die Muskelkraft, und reduziert das kardiovaskuläre Risiko wahrscheinlich effektiver. RT verbessert die Muskelkraft und tendenziell das metabolische Risiko, das bei einer reduzierten Muskelmasse im Alter erhöht ist. Wir empfehlen bei gesunden, alten Menschen vor allem ein Maximalkrafttraining mit einer Intensität von 60–80% des EWM, 8–15 Wiederholungen pro Übung und einem Volumen von 3–6 Sätzen pro Muskelgruppe und Woche. ET sollte ergänzend 2-mal pro Woche mit einer Intensität von 60% VO2max (nach Karvonen) und einer wöchentlichen Nettotrainingszeit von 30 bis 60 Minuten durchgeführt werden.SummaryBACKGROUND: Aging is associated with loss in both muscle mass and the metabolic quality of skeletal muscle. A major part of these changes is associated with an age-related decrease in the level of physical activity and may be counteracted by endurance training (ET) and resistance training (RT). OBJECTIVE: Since both muscle strength and aerobic power decrease with age, we investigated what form of training might be best for improvements in physical performance in the elderly. In detail, we wanted to know whether systematic ET can augment muscle strength and/or whether systematic RT can augment the aerobic power of healthy elderly adults. METHODS: Forty-two volunteers (32 women, 10 men) were recruited for the study and randomized into three groups: 13 persons undertook a continuous 6-month ET program, 15 undertook a continuous 6-month RT program and 14 served as a control group. All persons performed a cycling test to measure aerobic power (VO2max) and maximum workload (Wmax) before and after the training period. Maximum strength was determined from one repetition maximum (1-RM). RESULTS: After 6 months of RT, maximum strength increased by an average of 15% for leg press (P < 0.01), 25% for bench press (P < 0.01) and 30% for bench pull (P < 0.001); ET showed no effect on maximum strength except for the 1-RM in bench pull. Aerobic power improved by 6% in the ET group and by 2.5% in the RT group, neither of which was significant. Maximum workload improved significantly by 31% in the ET group (P < 0.001) and by 6% in the RT group (P = 0.05). ET resulted in a significant 5.3% reduction of body fat (P < 0.05), whereas only RT increased lean body mass by 1.0 ± 0.5 kg. CONCLUSION: RT leads to a genuine increase in lean body mass and muscle strength in healthy elderly adults and is therefore the best method for treatment of amyotrophia. ET appears to be the most efficacious training mode for maintaining and improving maximum aerobic power in the elderly and should be viewed as a complement to RT. The loading intensity to promote hypertrophy should approach 60–80% of 1-RM with an exercise volume ranging from 3 to 6 sets per muscle group per week of 10–15 repetitions per exercise. ET should be performed on two days per week controlled by a heart rate according to 60% of VO2max and an exercise volume ranging from 30 to 60 minutes per week.

Pulmonary and Antiaggregatory Effects of Prostacyclin after Inhalation and Intravenous Infusion

Prostacyclin (PGI2) was administered by inhalation (50 micrograms/min) and intravenous infusion (15 ng/kg/min) in 5 healthy male volunteers. Irrespective of the route of administration this substance was shown to have no effects on respiratory indices studied, whereas a significant inhibition of ADP-induced platelet aggregation and a fall in vascular resistance could be demonstrated. Mainly because of the latter action it is suggested that PGI2, or a stable synthetic analogue, might become a potent drug in various pathological conditions, in which hypertension of various causes is a problem.

Strength training increases maximum working capacity in patients with COPD--randomized clinical trial comparing three training modalities.

BACKGROUND AND OBJECTIVE Skeletal muscle dysfunction contributes to exercise limitation in patients with chronic obstructive pulmonary disease (COPD). Strength training increases muscle strength and muscle mass, but there is an ongoing debate on the additional effect concerning the exercise capacity. The purpose of this study was to compare the effects of three different exercise modalities in patients with COPD including endurance training (ET), progressive strength training (ST) and the combination of strength training and endurance training (CT). DESIGN A prospective randomized trial. METHODS Thirty-six patients with COPD were randomly allocated either to ET, ST, or CT. Muscle strength, cardiopulmonary exercise testing, lung function testing and quality of life were assessed before and after a 12-week training period. RESULTS Exercise capacity (Wmax) increased significantly in all three training groups with increase of peak oxygen uptake (VO2peak) in all three groups, reaching statistical significance in the ET group and the CT group. Muscle strength (leg press, bench press, bench pull) improved in all three training groups, with a higher improvement in the ST (+39.3%, +20.9%, +20.3%) and the CT group (+43.3%, +18.1%, +21.6%) compared to the ET group (+20.4%, +6.4%, +12.1%). CONCLUSIONS Progressive strength training alone increases not only muscle strength and quality of life, but also exercise capacity in patients with COPD, which may have implications in prescription of training modality. CLINICALTRIALS.GOV IDENTIFIER: NCT01091623.

Effects of progressive strength training on muscle mass in type 2 diabetes mellitus patients determined by computed tomography

ZusammenfassungGRUNDLAGEN: Ziel dieser Untersuchung war es, die Effekte eines 4-monatigen progressiven Krafttrainingprogramms auf die Muskel- und Fettmasse, gemessen mittels Computertomographie, bei Diabetes mellitus Typ-2-Patienten zu bestimmen und die Veränderungen der Muskelquerschnitte auf den Glukosestoffwechsel zu untersuchen. METHODIK: Zwanzig Patienten (mittleres Alter ± SE: 56,4 ± 0,9 a) nahmen an einem supervidierten 4-monatigen Krafttrainingprogramm 3 Tage/Woche teil. Muskel und Fettmasse wurden mittels Computertomographie vor und unmittelbar nach dem Training gemessen. Ebenso wurde der Glukosestoffwechsel (HbA1C), als auch anthropometrische Daten (BMI, Hautfalte), zum Zeitpunkt 0 und nach 4 Monaten erhoben. ERGEBNISSE: Nach dem Krafttraining verbesserte sich die Muskelkraft signifikant in allen gemessenen Muskeln. Der M. quadriceps vergrößerte sich um 2,4 % (von 7,99 ± 0,3 cm3 auf 8,18 ± 0,3 cm3, p = 0,003) in der rechten und um 3,9 % (von 8,1 cm3 ± 0,4 auf 8,41 ± 0,5 cm3, p = 0.04) in der linken unteren Extremität (bestimmt mittels Muskelquerschnittsmessungen). Das Fettgewebe verringerte sich von 0,66 ± 0,1 cm3 auf 0,56 ± 0,12 cm3 im rechten (15,3 % Reduktion) und von 0,58 ± 0,12 cm3 auf 0,37 ± 0,13 cm3 im linken Bein (35,8 % Reduktion), insgesamt fand sich eine Fettquerschnittsreduktion von 24,8 %. Die Fettmasse wurde signifikant reduziert, während die Muskelmasse signifikant zunahm. Es zeigten sich keine signifikanten Korrelationen zwischen Muskelquerschnittvermehrung und Hba1C oder Muskelkraft. SCHLUSSFOLGERUNGEN: Krafttraining verbessert sowohl die Muskelmasse als auch das Verhältnis Muskel zu Fett bei Diabetes mellitus Typ-2-Patienten. Jedoch korrelieren die Veränderungen der Muskelmasse (bestimmt mittels Computertomographie) nach dem Training nicht mit den Veränderungen im HbA1C.SummaryOBJECTIVE: To examine the effect of a 4-month progressive strength training program on muscle and fat mass assessed by computed tomography (CT) in type 2 diabetes mellitus (T2DM) patients, and to assess the relationships of changes in muscle cross-section area (CSA) with glycaemic control. METHODS: Twenty adults (mean age ± SE: 56.4 ± 0.9 a) with T2DM participated in a supervised strength training program for 4 months 3 days/week. Muscle and fat areas of the quadriceps muscle were estimated by CT volumetry before and immediately after the training. Glycaemic (HbA1c) and anthropometric (BMI, skinfolds) measurements were assessed at 0 and 4 months, respectively. RESULTS: After strength training, muscle strength increased significantly in all measured muscle groups. Quadriceps size (CSA of the muscle) was increased by 2.4% (from 7.99 ± 0.3 cm3 to 8.18 ± 0.3 cm3, p = 0.003) for the right extremity, 3.9% (from 8.1 ± 0.4 cm3 to 8.41 ± 0.5 cm3, p = 0.04) for the left side. Fat tissue CSA reduced from 0.66 ± 0.1 cm3 to 0.56 ± 0.12 cm3 for the right leg (15.3% reduction) and from 0.58 ± 0.12 cm3 to 0.37 ± 0.13 cm3 for the left leg (35.8% reduction), resulting in a mean fat CSA reduction of 24.8%. Fat mass assessed by skin folds was significantly reduced and lean body mass was significantly increased. The change in muscle CSA was not correlated with the changes in HbA1c or muscle strength. CONCLUSIONS: Strength training significantly improves both muscle mass and the muscle to fat ratio in T2DM. However, changes in muscle observed with computed tomography were not related to changes observed in HbA1c with training.

Abnormal pulmonary arterial pressure limits exercise capacity in patients with COPD

ZusammenfassungZIELE: Das Vorliegen einer pulmonalen Hypertension ist häufig bei Patienten mit chronisch obstruktiver Lungenerkrankung (COPD) anzutreffen. Der mittlere pulmonalarterielle Druck (mPAP) ist in Ruhe oft nur gering erhöht, zeigt aber einen pathologischen Anstieg unter Belastung. Das Ziel dieser Studie ist es, die Leistungsfähigkeit und den pulmonalen Gasaustausch bei COPD Patienten mit und ohne pulmonalarterieller Hypertension zu untersuchen. PATIENTEN UND METHODEN: Bei 42 Patienten mit COPD Grad II-IV (28 Männer, 14 Frauen) wurden eine Bodyplethysmographie, eine symptomlimitierte Fahrradergospirometrie sowie eine Rechtsherzkatheteruntersuchung durchgeführt. RESULTATE: 32 von 42 Patienten (76%) zeigten einen erhöhten mPAP in Ruhe (PH mPAP = 26,8 ± 5,9 mmHg), bei 10 Patienten war der mPAP in Ruhe im Normbereich (NPH, mPAP = 16,8 ± 2 mmHg). Es gab keinen signifikanten Unterschied hinsichtlich der lungenfunktionellen Parameter in beiden Gruppen. Die maximale Sauerstoffaufnahme (VO2max) war signifikant niedriger in der PH Gruppe (785 ± 244 ml/min) im Vergleich zur NPH Gruppe (1052 ± 207 ml/min, p = 0,004). Es zeigte sich in der PH Gruppe eine erhöhte Totraumventilation mit signifikant erhöhtem Atemäquivalent für CO2 (VECO2 47,3 ± 10 vs 38,6 ± 3,5, p = 0,025) und signifikant höherem arterio-endtidalen CO2 Partialdruck [p(a-ET)CO2]. Der pulmonalarterielle Widerstand (PVR) in Ruhe zeigte eine negative Korrelation hinsichtlich der VO2max, VE/VCO2 und dem arterio-endtidalen CO2 Partialdruck [p(a-ET)CO2]. ZUSAMMENFASSUNG: Patienten mit COPD und erhöhter pulmonalarterieller Druckwerte in Ruhe zeigen eine Verschlechterung des pulmonalen Gasaustausches unter Belastung, eine Beeinträchtigung der maximalen Sauerstoffaufnahme und somit eine limitierte Leistungsfähigkeit.SummaryOBJECTIVE: Pulmonary hypertension (PH) is common in patients with chronic obstructive pulmonary disease (COPD). Mean pulmonary artery pressure (mPAP) is often only slightly elevated at rest but is increased by exercise. The purpose of this study was to determine whether abnormal pulmonary artery pressure impairs exercise capacity in patients with COPD. PATIENTS AND METHODS: 42 patients with moderate-to-very-severe COPD (28 men, 14 women) underwent symptom-limited incremental cardiopulmonary exercise testing and also right-heart catheterization at rest. Abnormal pulmonary artery pressure was defined as mPAP > 20 mmHg at rest. RESULTS: Resting mPAP was elevated in 32 patients (PH, mPAP = 26.8 ± 5.9 mmHg) and normal in 10 non-hypertensive (NPH) patients (NPH, mPAP = 16.8 ± 2 mmHg). There were no significant differences in lung function between the PH and NPH groups. Maximum oxygen uptake during exercise (VO2max) was significantly lower in PH (785 ± 244 ml/min) than in NPH (1052 ± 207 ml/min, P = 0.004). Dead-space ventilation (Vd/Vt) was greater in PH (P = 0.05) with higher VE/VCO2 (ratio of minute ventilation to carbon dioxide output = 47.3 ± 10 vs 38.6 ± 3.5, P = 0.025) and significantly higher arterial-end-tidal pCO2 difference [p(a-ET)CO2]. Pulmonary vascular resistance measured at rest correlated significantly with VO2max, VE/VCO2 and p(a-ET)CO2. CONCLUSIONS: In patients with COPD, abnormal pulmonary artery pressure impairs gas exchange, decreases maximum oxygen uptake during exercise and impairs exercise capacity.

Intravenous magnesium sulfate for bronchial hyperreactivity: A randomized, controlled, double‐blind study

Magnesium has been shown to be helpful in the treatment of acute exacerbations of asthma. Conflicting data exist concerning the effect of magnesium on bronchial hyperreactivity.

Medizinische Trainingstherapie – eine unterschätzte Komponente der Langzeittherapie chronischer Erkrankungen

In dieser Ausgabe der Wiener Klinischen Wochenschrift wird eine Arbeit von R. H. Zwick et al. präsentiert, in der die Ergebnisse von einem Jahr ambulanter, wohnortnaher medizinischer Trainingstherapie bei PatientInnen mit COPD der Stadien (nach GOLD) II–IV vorgestellt werden [1]. Die PatientInnen wurden entweder aus einer pulmologischen Abteilung nach einem stationären Aufenthalt oder von einem pulmologischen stationären Rehabilitationszentrum rekrutiert, so dass angenommen werden kann, dass die Möglichkeiten der konventionellen medikamentösen Therapie maximal ausgenützt waren. Es handelt sich um eine offene Studie, was bei der Anwendung von körperlichem Training als Therapiemaßnahme wohl auch nicht anders möglich ist. Die Studie ist prospektiv angelegt, es fehlt aber eine Kontrollgruppe mit randomisierter Zuteilung! Wenn sich die Redaktion der WKW dennoch zu einer Publikation entschlossen hat, dann sicher aus zwei Gründen:

Comparison of Metabolic and Biomechanic Responses to Active vs. Passive Warm-up Procedures before Physical Exercise

Brunner-Ziegler, S, Strasser, B, and Haber, P. Comparison of metabolic and biomechanic responses to active vs. passive warm-up procedures before physical exercise. J Strength Cond Res 25(4): 909-914, 2011-Active warm-up before physical exercise is a widely accepted practice to enhance physical performance, whereas data on modalities to passively raise tissue temperature are rare. The study compared the effect of active vs. passive warm-up procedures before exercise on energy supply and muscle strength performance. Twenty young, male volunteers performed 3 spiroergometer-test series without prior warm-up and after either an active or passive warm-up procedure. Oxygen uptake (&OV0312;O2), heart rate (HR), pH value, and lactate were determined at 80% of individual &OV0312;O2max values and during recovery. Comparing no prior warm-up with passive warm-up, pH values were lower at the fourth test minute (p < 0.004), and lactate values were higher at the sixth and third minutes of recovery (p < 0.01 and p < 0.010, respectively), after no prior warm-up. Comparing active with passive warm-up, HR was lower, and &OV0312;o2 values were higher at the fourth and sixth test minutes (p < 0.033 and p < 0.011, respectively, and p < 0.015 and p < 0.022, respectively) after active warm-up. Differentiation between active and passive warm-up was more pronounced than between either warm-up or no warm-up. Conditions that may promote improved performance were more present after active vs. passive warm-up. Thus, athletes may reach the metabolic steady state faster after active warm-up.