Aerobic capacity reference data in 3816 healthy men and women 20-90 years

Purpose: To provide a large reference material on aerobic fitness and exercise physiology data in a healthy population of Norwegian men and women aged 20–90 years. Methods: Maximal and sub maximal levels of VO2, heart rate, oxygen pulse, and rating of perceived exertion (Borg scale: 6–20) were measured in 1929 men and 1881 women during treadmill running. Results: The highest VO2max and maximal heart rate among men and women were observed in the youngest age group (20–29 years) and was 54.4±8.4 mL·kg−1·min−1 and 43.0±7.7 mL·kg−1·min−1 (sex differences, p<0.001) and 196±10 beats·min−1 and 194±9 beats·min−1 (sex differences, p<0.05), respectively, with a subsequent reduction of approximately 3.5 mL·kg−1·min−1 and 6 beats·min−1 per decade. The highest oxygen pulses were observed in the 3 youngest age groups (20–29 years, 30–39 years, 40–49 years) among men and women; 22.3 mL·beat−1±3.6 and 14.7 mL·beat−1±2.7 (sex differences, p<0.001), respectively, with no significant difference between these age groups. After the age of 50 we observed an 8% reduction per decade among both sexes. Borg scores appear to give a good estimate of the relative exercise intensity, although observing a slightly different relationship than reported in previous reference material from small populations. Conclusion: This is the largest European reference material of objectively measured parameters of aerobic fitness and exercise-physiology in healthy men and women aged 20–90 years, forming the basis for an easily accessible, valid and understandable tool for improved training prescription in healthy men and women.© 2013 Loe et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Evaluation of Kalman filters for estimation of the annular bottomhole pressure during drilling

Estimation of the annular pressure at critical locations in the well is crucial for high-precision pressure control. Certain parameters which are important in order to determine the pressure profile of the well (in particular the friction factor, bulk modulus and density in the annulus), are encumbered with high uncertainty and are besides, continuously, but slowly changing. The objective of the thesis is to employ various Kalman filter designs estimation of the bottomhole pressure and certain important parameters/slowly varying variables, during drilling. Topics that should be addressed are: 1) Literature review of the theory of Kalman filters design 2) Design and implement an Extended Kalman filter (EKF) and possibly the Unscented Kalman filter (UKF) for a) Estimation of the annulus bottom-hole pressure b) Esimation of the friction coefficient, bulk modulus and density in the annulus 3) Analyse the performance/robustness of the observer in important cases, in particular: a) Pipe connection b) Pump ramp up/down 4) Examine observer performance to unmodeled dynamics by testing the Kalman filter against data sets from Wemod 5) Evaluate performance of the observer against experimental data from Grane

High-intensity aerobic exercise and cardiovascular health

Regelmessig fysisk aktivitet bedrer den fysiske formen, og er dokumentert å være en viktig bidragsyter med tanke på å redusere forekomsten av sykdom og dødelighet. Det maksimale oksygenopptaket, som er det beste målet på arbeidskapasitet, er vist å være en svært sterk indikator på dødelighet både hos friske og hos pasienter med hjerte-karsykdom. Regelmessig utholdenhetstrening for å øke maksimalt oksygenopptak er derfor anbefalt for bedret helse og økt livslengde. Selv om dette er etablert kunnskap, vet man lite om hvilken intensitet kondisjonstreningen bør gjennomføres med for å oppnå best mulig helsegevinst. Hensikten med denne doktorgradsavhandlingen var derfor å kartlegge hvilken intensitet i kondisjonstreningen som gir best effekt med tanke på å øke det maksimale oksygenopptaket blant pasienter med koronarsykdom. Vi ønsket også å studere hvorvidt intensiteten er viktig for å bedre fysisk form og redusere risikofaktorer for hjerte-karsykdom hos pasienter med metabolsk syndrom, som har en sterk opphopning av disse risikofaktorene. Derfor sammenliknet vi aerob intervalltrening med høy intensitet (80-90 % av maksimalt oksygenopptak) med kontinuerlig kondisjonstrening med moderat intensitet (50-60 % av maksimalt oksygenopptak) der total treningsmengde var lik. Videre ønsket vi å undersøke hvordan blodårenes funksjon og elastisitet ble påvirket av ulik type trening, både blant unge trente og utrente, og blant pasienter med metabolsk syndrom. Resultatene viste at trening med høy intensitet ga bedre effekter enn moderat intensitet for å bedre aerob kapasitet og redusere kjente risikofaktorer forbundet med hjerte-karsykdom, inkludert blodårefunksjonen. Avhandlingen kan derfor bidra med ny innsikt med tanke på bruk av aerob intervalltrening for mer effektivt å bedre kondisjonen og dermed helsen, både blant hjertesyke og hos individer med forhøyet risiko for fremtidig hjerte-karsykdomDr.philos.Dr.philos

Barn av foreldre med psykiske lidelser eller alkoholmisbruk. Omfang og konsekvenser

publishedVersio

Mechanisms of exercise-induced improvements in the contractile apparatus of the mammalian myocardium

One of the main outcomes of aerobic endurance exercise training is the improved maximal oxygen uptake, and this is pivotal to the improved work capacity that follows the exercise training. Improved maximal oxygen uptake in turn is at least partly achieved because exercise training increases the ability of the myocardium to produce a greater cardiac output. In healthy subjects, this has been demonstrated repeatedly over many decades. It has recently emerged that this scenario may also be true under conditions of an initial myocardial dysfunction. For instance, myocardial improvements may still be observed after exercise training in post-myocardial infarction heart failure. In both health and disease, it is the changes that occur in the individual cardiomyocytes with respect to their ability to contract that by and large drive the exercise training-induced adaptation to the heart. Here, we review the evidence and the mechanisms by which exercise training induces beneficial changes in the mammalian myocardium, as obtained by means of experimental and clinical studies, and argue that these changes ultimately alter the function of the whole heart and contribute to the changes in whole-body function

Palatability of two artificial feeds for reindeer

Two groups of 15 reindeer were used to test the palatability of two artificial diets. None of the animals had experienced the diets before. Trials were carried out from April to mid May. Each group of animals was kept in a separate corral (600 sq. meters). Both groups were fed lichens for three days befort trials began. Then they were offered a concentrate feed (RF-80) or &laquo;Mill Waste Product&raquo; (MWP) ad libitum. Both groups ate little or nothing for the first three days of the trial and so lichens were mixed with the two experimental feeds. The mean voluntary food intake of the RF-80-group increased from 0.8 Kg/day/animal to 1.8 Kg/day/animal after three weeks. A mixed feed, RF-80/lichen, was only used the first day for animals in the RF-80 group. Reindeer refused to eat MWP for twelve days despite mixing it with lichens. They were then offered RF-80 ad lib. without a mixture of lichens. The mean voluntary intake of these animals increased from 1.3 Kg RF-80/day/animal on day 13 to 2.3 Kg/day/animal by day 26. Two calves in the MWP-group got diarrhoea after refeeding with RF-80

Application of the speed-duration relationship to normalize the intensity of high-intensity interval training

The tolerable duration of continuous high-intensity exercise is determined by the hyperbolic Speed-tolerable duration (S-tLIM) relationship. However, application of the S-tLIM relationship to normalize the intensity of High-Intensity Interval Training (HIIT) has yet to be considered, with this the aim of present study. Subjects completed a ramp-incremental test, and series of 4 constant-speed tests to determine the S-tLIM relationship. A sub-group of subjects (n = 8) then repeated 4 min bouts of exercise at the speeds predicted to induce intolerance at 4 min (WR4), 6 min (WR6) and 8 min (WR8), interspersed with bouts of 4 min recovery, to the point of exercise intolerance (fixed WR HIIT) on different days, with the aim of establishing the work rate that could be sustained for 960 s (i.e. 4×4 min). A sub-group of subjects (n = 6) also completed 4 bouts of exercise interspersed with 4 min recovery, with each bout continued to the point of exercise intolerance (maximal HIIT) to determine the appropriate protocol for maximizing the amount of high-intensity work that can be completed during 4×4 min HIIT. For fixed WR HIIT tLIM of HIIT sessions was 399±81 s for WR4, 892±181 s for WR6 and 1517±346 s for WR8, with total exercise durations all significantly different from each other (P&#60;0.050). For maximal HIIT, there was no difference in tLIM of each of the 4 bouts (Bout 1: 229±27 s; Bout 2: 262±37 s; Bout 3: 235±49 s; Bout 4: 235±53 s; P&#62;0.050). However, there was significantly less high-intensity work completed during bouts 2 (153.5±40. 9 m), 3 (136.9±38.9 m), and 4 (136.7±39.3 m), compared with bout 1 (264.9±58.7 m; P&#62;0.050). These data establish that WR6 provides the appropriate work rate to normalize the intensity of HIIT between subjects. Maximal HIIT provides a protocol which allows the relative contribution of the work rate profile to physiological adaptations to be considered during alternative intensity-matched HIIT protocols