Time course of changes in endurance capacity : a 1-yr training study

PURPOSE: To investigate the magnitude and the time course of changes in endurance capacity during the first year of an aerobic endurance training program with constant HR prescription. METHODS: Eighteen previously untrained subjects (7 males and 11 females, 42 +/- 5 yr, BMI of 24.3 +/- 2.5 kg x m(-2), and maximal oxygen uptake (VO(2max)) of 37.7 +/- 4.6 mL x min(-1) x kg(-1)) completed a 12-month jogging/walking program on 3 d x wk(-1) 45 min per session with a constant HR prescription of 60% HR reserve. Exhaustive treadmill tests were conducted before the intervention and after 3, 6, 9, and 12 months of training. In addition, submaximal tests on an indoor running track were performed every 4 wk. RESULTS: After 12 months, VO(2max) had increased by 0.36 +/- 0.33 L x min(-1) (median [interquartile range]: 16% [9%-20%], P < 0.001). After 3, 6, and 9 months, 52%, 65%, and 79% of this increase were reached, respectively. Resting HR decreased by a total of 9 +/- 6 min(-1) (P<0.001). Of this change, 47% and 102% had occurred after 3 and 6 months, respectively. Submaximal exercise HR during the treadmill tests decreased by 11 +/- 7 min(-1) (P < 0.001) on average. After 3 and 6 months of training, 93% and 101% of this change were observed, respectively. The running track tests revealed that submaximal exercise HR did not change significantly after the ninth week of training. CONCLUSIONS: Beginners in recreational endurance exercise are advised to increase their training stimulus after 6 months of training to maintain training effectiveness because no further significant changes in endurance capacity were observed thereafter. When planning future endurance training studies in untrained subjects, it should be taken into account that submaximal exercise HR might reflect endurance changes during the first week only, whereas VO(2max) remains responsive after several months

Differentiated resistance training of the paravertebral muscles in patients with unstable spinal bone metastasis under concomitant radiotherapy: study protocol for a randomized pilot trial

Background: Metastatic bone disease is a common and severe complication in patients with advanced cancer. Radiotherapy (RT) has long been established as an effective local treatment for metastatic bone disorder. This study assesses the effects of RT combined with muscle-training exercises in patients with unstable bone metastases of the spinal column from solid tumors. The primary goal of this study is to evaluate the feasibility of muscle-training exercises concomitant to RT. Secondly, quality of life, fatigue, overall and bone survival, and local control will be assessed. Methods/Design: This study is a single-center, prospective, randomized, controlled, explorative intervention study with a parallel-group design to determine multidimensional effects of a course of exercises concomitant to RT on patients who have unstable metastases of the vertebral column, first under therapeutic instruction and subsequently performed by the patients themselves independently for strengthening the paravertebral muscles. On the days of radiation treatment the patients will be given four different types of exercises to ensure even isometric muscle training of all the spinal muscles. In the control group progressive muscle relaxation will be carried out parallel to RT. The patients will be randomized into two groups: differentiated muscle training or progressive muscle relaxation with 30 patients in each group. Discussion: Despite the clinical experience that RT is an effective treatment for bone metastases, there is insufficient evidence for a positive effect of the combination with muscle-training exercises in patients with unstable bone metastases. Our previous DISPO-1 trial showed that adding muscle-training exercises to RT is feasible, whereas this was not proven in patients with an unstable spinal column. Although associated with several methodological and practical challenges, this randomized controlled trial is needed. Trial registration: ClinicalTrials.gov, identifier: NCT02847754. Registered on 27 July 2016

Improvements in fitness are not obligatory for exercise training-induced improvements in CV risk factors.

The purpose of this study was to assess whether changes in physical fitness relate to changes in cardiovascular risk factors following standardized, center-based and supervised exercise training programs in subjects with increased cardiovascular risk. We pooled data from exercise training studies of subjects with increased cardiovascular risk (n = 166) who underwent 8-52 weeks endurance training. We determined fitness (i.e., peak oxygen uptake) and traditional cardiovascular risk factors (body mass index, blood pressure, total cholesterol, high-density lipoprotein cholesterol), before and after training. We divided subjects into quartiles based on improvement in fitness, and examined whether these groups differed in terms of risk factors. Associations between changes in fitness and in cardiovascular risk factors were further tested using Pearson correlations. Significant heterogeneity was apparent in the improvement of fitness and individual risk factors, with nonresponder rates of 17% for fitness, 44% for body mass index, 33% for mean arterial pressure, 49% for total cholesterol, and 49% for high-density lipoprotein cholesterol. Neither the number, nor the magnitude, of change in cardiovascular risk factors differed significantly between quartiles of fitness change. Changes in fitness were not correlated with changes in cardiovascular risk factors (all P > 0.05). Our data suggest that significant heterogeneity exists in changes in peak oxygen uptake after training, while improvement in fitness did not relate to improvement in cardiovascular risk factors. In subjects with increased cardiovascular risk, improvements in fitness are not obligatory for training-induced improvements in cardiovascular risk factors

Tennis play intensity distribution and relation with aerobic fitness in competitive players

15 p.Los objetivos de este estudio fueron (1) describir la intensidad relativa del juego de tenis simulado en función del tiempo acumulado en tres zonas de intensidad metabólica y (2) determinar las relaciones entre esta distribución de intensidad de juego y la aptitud aeróbica de un grupo de jugadores competitivos. 20 jugadores masculinos de nivel avanzado a élite (ITN) realizaron una prueba de tenis de resistencia específica en el campo incremental hasta el agotamiento para determinar el consumo máximo de oxígeno (VO2max) y los umbrales de ventilación primero y segundo (VT1, VT2). Los parámetros de ventilación y de intercambio de gases se monitorizaron utilizando un analizador de gas portátil telemétrico (K4 b2, Cosmed, Roma, Italia). Dos semanas después, los participantes jugaron un juego de tenis simulado contra un oponente de nivel similar. Las zonas de intensidad (1: baja, 2: moderada y 3: alta) fueron delimitadas por los valores individuales de VO2 correspondientes a VT1 y VT2, y se expresaron como porcentaje del VO2 máximo y la frecuencia cardíaca. Cuando se expresó en relación con el VO 2 máx. El porcentaje de tiempo de juego en la zona 1 (77 ± 25%) fue significativamente mayor (p <0,001) que en la zona 2 (20 ± 21%) y la zona 3 (3 ± 5%). Se encontraron correlaciones positivas de moderadas a altas entre VT1, VT2 y VO2max, y el porcentaje del tiempo de juego transcurrido en la zona 1 (r = 0,68-0,75), así como las correlaciones inversas de bajas a altas entre las variables metabólicas y el porcentaje de tiempo empleado en las zonas 2 y 3 (r = -0.49–0.75). Los jugadores con mejor aptitud aeróbica juegan a intensidades relativamente más bajas. Concluimos que los jugadores pasaron más del 75% del tiempo en su zona de baja intensidad, con menos del 25% del tiempo dedicado a intensidades moderadas a altas. La aptitud aeróbica parece determinar la intensidad metabólica que los jugadores pueden mantener durante todo el juegoS

Magnitude, variability, and time course of adaptive responses to 50 wk recreational endurance training

Bislang liegen kaum wissenschaftlich gesicherte Informationen darüber vor, welches Ausmaß, welche Variabilität und welchen Zeitverlauf Anpassungserscheinungen innerhalb des ersten Jahres nach Beginn eines gesundheitssportlichen Ausdauertrainings aufweisen. Die meisten Studien dauerten nur wenige Monate oder untersuchten für Einsteiger ungeeignet intensive Trainingsprogramme. Kenntnisse der genannten Parameter erscheinen notwendig, um Gesundheitssportler zu betreuen und Studien adäquat zu planen. Daher sollten das Ausmaß, die Variabilität und der Zeitverlauf von verschiedenen Adaptationen an ein gesundheitssportliches Ausdauertraining über ein Jahr untersucht werden. Achtzehn initial untrainierte Probanden (7 Männer/11 Frauen; 42±5 Jahre; Body-Mass-Index: 24,3±2,5 kg/m2; maximale Sauerstoffaufnahme (VO2max): 37,7±4,6 ml/min/kg) schlossen ein 50-wöchiges Trainingsprogramm, bestehend aus dreimal wöchentlich 45 min Laufen oder Walking mit konstanter Herzfrequenz (HF)-Vorgabe von 60% HF-Reserve, ab. Laufbandtests zur Bestimmung von HF, Blutlaktatkonzentration und Atemgasparametern sowie venöse Blutentnahmen wurden im Rahmen eines Eignungs- und Gewöhnungstests, eines Eingangstests sowie nach drei, sechs, neun und zwölf Monaten Training durchgeführt. Zusätzlich erfolgten Fahrradergometrien vor Trainingsbeginn und nach Abschluss des Trainings sowie spirometrische Messungen des Ruheumsatzes vor Trainingsbeginn, nach sechs und nach zwölf Monaten Training. Submaximale Feldstufentests zur Bestimmung der HF-Leistungskurve fanden ergänzend innerhalb der ersten drei Trainingsmonate 14-täglich und im weiteren Studienverlauf vierwöchentlich statt. Durch das Ausdauertraining veränderte sich das Körpergewicht nicht signifikant (p=0,17; n=18), während sich der Körperfettanteil signifikant um insgesamt im Mittel -3,7±2,3% (-7,8 bis +1,8%) veränderte (p<0,001; n=18). Die VO2max veränderte sich im Trainingsverlauf signifikant um insgesamt durchschnittlich +5,7±4,1 ml/min/kg (-1,1 bis +13,8 ml/min/kg; p<0,001; n=17). Nach drei, sechs bzw. neun Monaten Training waren durchschnittlich 58, 75 bzw. 84 % der Ein-Jahres-Gesamtveränderung erreicht. Bei vier der 17 Probanden stieg die VO2max im Trainingsverlauf nicht an. Die Ruheherzfrequenz der Probanden veränderte sich insgesamt um durchschnittlich -9±6 /min (-24 bis +1 /min; p<0,001; n=18) und 47 bzw. 102 % der Ein-Jahres-Gesamtveränderung waren nach drei bzw. sechs Monaten Training erreicht. Vier der 18 Studienteilnehmer zeigten keine Abnahme der Ruheherzfrequenz. Die HF-Leistungskurve beim Laufbandtest verschob sich durch das Ausdauertraining insgesamt um im Mittel -11±7 /min (-22 bis +1 /min; p<0,001; n=18). Nach drei bzw. sechs Monaten Training waren 93 bzw. 101 % der Ein-Jahres-Gesamtveränderung erreicht. Bei drei der 18 Probanden verschob sich die HF-Leistungskurve nicht. Die submaximalen Feldstufentests ergaben nach der neunten Trainingswoche keine weitere Verschiebung der HF-Leistungskurve (p>0,59; n=18). Die Leistung an der individuellen anaeroben Schwelle (IAS) im fahrradergometrischen Stufentest veränderte sich im Trainingsverlauf signifikant um durchschnittlich +16±9 W (-1 bis +35 W; p<0,001; n=15). Der Ruheumsatz der Probanden stieg im Studienverlauf weder absolut noch körpergewichtsbezogen signifikant an (p=0,43 bzw. p=0,27; n=17). Auch Gesamtcholesterin, HDL- und LDL-Cholesterin veränderten sich nicht signifikant (p=0,21 bzw. p=0,22 bzw. p=0,16; n=18). Unter den Studienteilnehmern gab es insgesamt keine "Nonresponder" in dem Sinne, dass alle Deskriptoren der Ausdauerleistungsfähigkeit ohne Effekt blieben. Alle untersuchten Indikatoren der Ausdauerleistungsfähigkeit hatten nach sechs Monaten Training mindestens 75% ihrer Ein-Jahres-Gesamtveränderung erreicht. Es erscheint für Sporteinsteiger daher empfehlenswert, ihre Trainingsvorgabe nach etwa diesem Zeitraum zu erhöhen, um weiterhin Leistungsverbesserungen zu erzielen. Da die HF-Leistungskurve bereits nach drei Monaten Training über 90% ihrer Ein-Jahres-Gesamtveränderung erreicht hatte, scheint sie bei längeren Studien mit konstanter Trainingsvorgabe keinen geeigneten Parameter zur Dokumentation von Adaptationen darzustellen. Bei etwa 70% der Studienteilnehmer blieb mindestens ein untersuchter Parameter unverändert. Zur kompletten Dokumentation und Charakterisierung individueller Leistungsverbesserungen sollten daher Parameter unterschiedlicher Adaptations- und Messebenen erfasst werden. Die vorliegende Untersuchung wirft Zweifel an der Existenz von globalen Nonrespondern bei gesundheitssportlichem Ausdauertraining auf. Untersuchungen an größeren Stichproben sind notwendig, um dem nachzugehen. Bei konstanter Trainingsvorgabe von 60 % HF-Reserve sind nach einem Jahr dreimal wöchentlich 45 min Ausdauertraining im Mittel Anstiege der VO2max um etwa 6 ml/min/kg sowie Absenkungen der Ruheherzfrequenz und der HF-Leistungskurve um etwa 10 /min zu erwarten.So far, there is only little information available about the magnitude, the variability, and the time course of adaptive responses during the first year of a recreational endurance training program. Most studies were conducted over short periods of time only and surveyed endurance training programs that are not suitable for recreational athletes. Knowledge about the characteristics of endurance training responses seems useful to supervise recreational athletes and to adequately plan future studies. Therefore, the magnitude, the variability, and the time course of adaptations to one year of recreational endurance training should be investigated. Eighteen initially untrained subjects (7 males/ 11 females, 42 ± 5 yr, body mass index: 24.3 ± 2.5 kg/m2, maximal oxygen uptake (VO2max): 37.7 ± 4.6 ml/min/kg) completed a 50 wk jogging/walking program on 3 days/week 45 min/session with a constant heart rate (HR) prescription of 60 % HR reserve. Exhaustive treadmill tests to determine HR, blood lactate concentration, and gas exchange parameters were conducted to habituate the subjects to the testing procedure and then prior to the training program and after 3, 6, 9, and 12 months of training. Furthermore, cycle ergometer tests were performed prior to the training program and after 12 months of training and resting metabolic rate (RMR) was measured in the beginning and after 6 and 12 months of training. Submaximal indoor track tests took place every two weeks during the first three months and every four weeks thereafter. The body weight of the subjects remained unchanged (p = 0.17, n = 18) whereas the body fat content changed significantly by -3.7 ± 2.3 % (-7.8 to +1.8 %) on average (p < 0.001, n = 18). VO2max changed significantly by +5.7 ± 4.1 ml/min/kg (-1.1 to +13.8 ml/min/kg, p < 0.001, n = 17). After 3, 6, and 9 months of training 58, 75 and 84 % of the total one-year-change were reached, respectively. Four of 17 subjects showed no increase in VO2max. Resting HR changed by a total of -9 ± 6 /min (-24 to +1 /min, p < 0.001, n = 18) and 47 and 102 % of the total one-year-change were reached after 3 and 6 months, respectively. In 4 of 18 subjects resting HR did not change. Submaximal exercise HR during the treadmill tests changed by -11 ± 7 /min (-22 to +1 /min) on average (p < 0.001, n = 18). After 3 and 6 months of training, 93 and 101 % of the total one-year-change had occurred, respectively. Three of 18 subjects showed no decrease in submaximal exercise HR. The indoor track tests revealed no further changes in submaximal exercise HR after the 9th wk of training (p > 0.59, n = 18). The individual anaerobic threshold (IAT) during the cycle ergometer tests changed significantly by +16 ± 9 W (-1 to +35 W, p < 0.001, n = 15). Neither RMR expressed in absolute terms nor RMR expressed per kg body weight changed significantly (p = 0.43 and p = 0.27, respectively, n = 17). Also, total cholesterol, HDL und LDL cholesterol did not change significantly (p = 0.21, p = 0.22, and p = 0.16, respectively, n = 18). Each individual showed changes in at least two of the surveyed parameters and, therefore, no complete "nonresponder\u27; to endurance exercise was identified. All indicators for endurance capacity had reached at least 75 % of their total one-year-change after 6 months of training. Beginners in endurance training should therefore be advised to increase their training stimulus after that point of time to reach further improvements. As submaximal exercise HR had reached more than 90 % of its total one-year-change after 3 months of training, it does not seem to be an appropriate indicator for endurance changes in longer training studies with a constant training stimulus. In about 70 % of the subjects at least one parameter did not change. It therefore seems necessary to assess different indicators of aerobic fitness if endurance changes are to be described completely. The present data question the existence of complete nonresponders to recreational endurance training. Further studies with larger sample sizes are needed to examine this. After one year of endurance training on 3 days/week for 45 min/session with a constant training stimulus of 60 % HR reserve, an increase in VO2max by 6 ml/min/kg and decreases in resting and submaximal exercise HR by about 10 /min can be expected