Sascha Härtel

Dr. Sascha Härtel


Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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2 December 2010 in European Review of Aging and Physical Activity
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SHSascha Härtel
Sascha Härtel
JGJens-Peter Gnam
Jens-Peter Gnam
SLSimone Löffler
Simone Löffler
KBKlaus Bös
Klaus Bös
Over the last few years, the estimation of energy expenditure with accelerometers has become more and more accurate due to improvements in sensor technology. Significant enhancement could be reached by model-based estimation regarding different activity types. The kmsMove-sensor (movisens GmbH, Karlsruhe, Germany) is a device that is used to compute human energy expenditure using motion-dependent calculation models. It is outfitted with an accelerometer to measure body acceleration during certain movements and activities. To validate its accuracy, the sensor was compared to indirect calorimetry as criterion measure. For this experiment, nine subjects (all males, age 46.4 ± 10.9 years, 28–64 years) were equipped with the kmsMove-sensor as well as a portable indirect calorimeter and their energy consumption was measured over a time period of 100 min. Additionally, the energy consumption of seven out of the above-mentioned nine subjects was measured over an average of 7 h. The measurements took place in a rehabilitation clinic, where the subjects completed their regular daily rehabilitation activities. An analysis of the data revealed ICCs between the kmsMove-sensor and indirect calorimetry for the time period of 100 min of 0.82 (0.38–0.96; p = 0.003) and for an averaged measuring time of 7 h of 0.81 (0.22–0.97; p = 0.01). Furthermore, a Bland–Altman analysis for the time period of 100 min led to a difference of the means of 4.3 kcal (limits of agreement: −94.3 and 102.9 kcal) and for the time period of an average of 7 h to −14.0 kcal (limits of agreement: −320.0 and 292.0 kcal). These findings indicate that the kmsMove-sensor is an appropriate measuring device with relatively good accuracy to assess human energy expenditure in rehabilitation patients. However, this study has some limiting aspects (small sample size, artificial setting) which could influence validity.

1 January 2013 in Frontiers in Psychology
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BHBirte von Haaren
Birte von Haaren
SLSimone Nadine Loeffler
Simone Nadine Loeffler
SHSascha Härtel
Sascha Härtel
PAPanagiota Anastasopoulou
Panagiota Anastasopoulou
JSJuergen Stumpp
Juergen Stumpp
KBKlaus Boes
Klaus Boes
Acute and regular exercise as well as physical activity is related to wellbeing and positive affect. Recent studies have shown that even daily, unstructured physical activities increase positive affect. However, the attempt to achieve adherence to physical activity or exercise in inactive people through public health interventions has often been unsuccessful. Most studies analyzing the activity-affect association in daily life, did not report participants´ habitual activity behavior. Thus, samples included active and inactive people, but they did not necessarily exhibit the same affective reactions to physical activity in daily life. Therefore the present study investigated whether the association between physical activity and subsequent affective state in daily life can also be observed in inactive individuals. We conducted a pilot study with 29 inactive university students (mean age 21.3 yrs ± 1.7) using the method of ambulatory assessment. Affect was assessed via electronic diary and physical activity was measured with accelerometers. Participants had to rate affect every two hours on a six item bipolar scale reflecting the three basic mood dimensions energetic arousal, valence and calmness. We calculated activity intensity level (mean Metabolic Equivalent (MET) value) and the amount of time spent in light activity over the last 15 minutes before every diary prompt and conducted within-subject correlations. We did not find significant associations between activity intensity and the three mood dimensions. Due to the high variability in within-subject correlations we conclude that not all inactive people show the same affective reactions to physical activity in daily life. Analyzing the physical activity-affect association of inactive people was difficult due to little variance and distribution of the assessed variables. Interactive assessment and randomized controlled trials might help solving these problems. Future studies should examine characteristics of affect

24 September 2014 in Sports
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SHSascha Härtel
Sascha Härtel
CKClaire Kutzner
Claire Kutzner
EWEva Westphal
Eva Westphal
MLMatthias Limberger
Matthias Limberger
MBMartin Burkart
Martin Burkart
KBKlaus Boes
Klaus Boes
Impaired exercise capacity is the core symptom of heart failure with preserved ejection fraction (HFpEF). We assessed effects of exercise training and Crataegus extract WS 1442 in HFpEF and aimed to identify mechanisms of action in an exploratory trial (German Clinical Trials Register DRKS00000259). 140 sedentary HFpEF NYHA II patients on standard treatment received eight weeks of aerobic endurance training and half were randomized to WS 1442 900 mg/day. Symptoms, 2 km walking time (T2km), parameters of exercise tolerance, cardiac and vascular function, muscular efficiency and skeletal muscular haemoglobin oxygen saturation (SO2) measured during a treadmill protocol were captured at baseline and after eight weeks. Adverse events were recorded during the trial. Mechanisms of action were explored by correlation and path analyses of changes. Symptoms and exercise capacity improved with training, but correlations between improvements were low and path models were rejected. SO2 increased, decreased or undulated with increasing exercise intensity in individual patients and was not altered by training. WS 1442 improved T2km (-12.7% vs. -8.4%, p = 0.019), tended to improve symptoms and to pronounce SO2-decrease with increasing exercise, an indicator of oxygen utilisation. Endurance training and WS 1442 were safe and well tolerated in combination with standard drug treatment.

19 October 2011 in MMW - Fortschritte der Medizin
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JKJanina Krell
Janina Krell
CKClaire Kutzner
Claire Kutzner
SHSascha Härtel
Sascha Härtel
KBKlaus Boes
Klaus Boes