Search results for "XE"
showing 10 items of 9661 documents
Durability is improved by both low and high intensity endurance training
2023
Introduction: This is one of the first intervention studies to examine how low- (LIT) and high-intensity endurance training (HIT) affect durability, defined as ‘time of onset and magnitude of deterioration in physiological-profiling characteristics over time during prolonged exercise’.Methods: Sedentary and recreationally active men (n = 16) and women (n = 19) completed either LIT (average weekly training time 6.8 ± 0.7 h) or HIT (1.6 ± 0.2 h) cycling for 10 weeks. Durability was analyzed before and after the training period from three factors during 3-h cycling at 48% of pretraining maximal oxygen uptake (VO2max): 1) by the magnitude and 2) onset of drifts (i.e. gradual change in energy ex…
Monitoring Training and Recovery during a Period of Increased Intensity or Volume in Recreational Endurance Athletes
2021
The purpose of the study was to examine the effects of progressively increased training intensity or volume on the nocturnal heart rate (HR) and heart rate variability (HRV), countermovement jump, perceived recovery, and heart rate-running speed index (HR-RS index). Another aim was to analyze how observed patterns during the training period in these monitoring variables were associated with the changes in endurance performance. Thirty recreationally trained participants performed a 10-week control period of regular training and a 10-week training period of either increased training intensity (INT, n = 13) or volume (VOL, n = 17). Changes in endurance performance were assessed by an incremen…
An Integrated Approach to Skeletal Muscle Health in Aging
2023
A decline in muscle mass and function represents one of the most problematic changes associated with aging, and has dramatic effects on autonomy and quality of life. Several factors contribute to the inexorable process of sarcopenia, such as mitochondrial and autophagy dysfunction, and the lack of regeneration capacity of satellite cells. The physiologic decline in muscle mass and in motoneuron functionality associated with aging is exacerbated by the sedentary lifestyle that accompanies elderly people. Regular physical activity is beneficial to most people, but the elderly need well-designed and carefully administered training programs that improve muscle mass and, consequently, both funct…
Improving Energy Expenditure Estimation in Wrist-Worn Wearables by Augmenting Heart Rate Data With Heat Flux Measurement
2021
Wearable electronics are often used for estimating the energy expenditure of the user based on heart rate measurement. While heart rate is a good predictor of calorie consumption at high intensities, it is less precise at low intensity levels, which translates into inaccurate results when estimating daily net energy expenditure. In this study, heart rate measurement was augmented with heat flux (HF) measurement, a form of direct calorimetry. A physical exercise test on a group of 15 people showed that HF measurement can improve the accuracy of calorie consumption estimates especially during rest and low-intensity activity when used in conjunction with heart rate information and vital backgr…
Heart rate recovery after maximal and submaximal exercise
2012
Pasi Karjalainen (2012). Heart rate recovery after maximal and submaximal exercise. Department of Biology of Physical Activity, University of Jyväskylä, Master thesis in exercise physiology, 76 pages. Heart rate recovery (HRR) after exercise reflects autonomic control of the heart. Heart rate recovery (HRR) has shown to have prognostic value among asymptomatic populations and patients with diseases. In addition, changes in HRR may reflect the effects of training load. The role of parasympathetic reactivation in decrease of heart rate (HR) is known to be strong immediately after the cessation of exercise. It is also shown that HRR is affected by the activity of the sympathetic system that is…
Post-exercise heart rate variability : a new approach to evaluation of exercise-induced physiological training load
2015
To improve maximal endurance performance, an optimal physiological training load, i.e. the balance between exercise and recovery, is required. In general, the goal of a single endurance exercise session is to transiently disturb body homeostasis after which a so-called supercompensation, an improvement in performance, can occur if the recovery period is adequate. The physical training load of a single exercise session consists of the combination of exercise intensity and duration. At the present time, there is no single tool to quantify the amount of disturbance of homeostasis that is equal to physiological training load of a single exercise session. Heart rate variability (HRV), the change…
Effects of eight weeks physical training on physical performance and heart rate variability in children
2013
Kraama, Liisa. 2013. Kahdeksan viikon fyysisen harjoittelun vaikutus lasten fyysiseen suorituskykyyn ja sydämen sykevaihteluun. Jyväskylän yliopisto, Liikuntabiologian laitos. Liikuntafysiologian Pro gradu –tutkielma. 52 s. Lasten ja kasvuikäisten nuorten fyysinen aktiivisuus ja aerobinen kapasiteetti ovat vähentyneet viimeisten vuosikymmenten aikana. Fyysisesti aktiivisilla aikuisilla on todettu olevan enemmän sydämen sykevaihtelua kuin vähemmän aktiivisilla. Aikuisilla on harjoittelun aikaansaamien fyysisen suorituskyvyn muutosten todettu olevan yhteydessä sykevaihtelun, erityisesti parasympaattista aktiivisuutta kuvaavaan korkean taajuuden sykevaihtelun, kasvuun. Tässä pro gradu -tutkiel…
Effects of eight weeks of physical training on physical performance and heart rate variability in children
2017
Study aim: Physically active adults have been shown to have higher heart rate variability (HRV) than less active adults, but less is known about children in this regard. In adults, training-induced changes in physical performance have been shown to be related to increase in HRV, especially in its high frequency component (HF), which is a marker of parasympathetic activity. The purpose of this study was to examine whether 8 weeks of instructed physical training would improve physical performance and cardiac autonomic function (HRV) in secondary school pupils and to examine the relationship between changes in physical performance and the function of the autonomic nervous system. Material and …
A Fixed Domain Approach in Shape Optimization Problems with Neumann Boundary Conditions
2008
Fixed domain methods have well-known advantages in the solution of variable domain problems, but are mainly applied in the case of Dirichlet boundary conditions. This paper examines a way to extend this class of methods to the more difficult case of Neumann boundary conditions.
Application of Periodic Frames to Image Restoration
2014
In this chapter, we present examples of image restoration using periodic frames. Images to be restored were degraded by blurring, aggravated by random noise and random loss of significant number of pixels. The images are transformed by periodic frames designed in Sects. 17.2 and 17.4, which are extended to the 2D setting in a standard tensor product way. In the presented experiments, performances of different tight and semi-tight frames are compared between each other in identical conditions.