TY  - JOUR
A1  - Jannasch, Franziska
A1  - Nickel, Daniela V.
A1  - Bergmann, Manuela M.
A1  - Schulze, Matthias Bernd
T1  - A new evidence-based diet score to capture associations of food consumption and chronic disease risk
JF  - Nutrients / Molecular Diversity Preservation International (MDPI)
N2  - Previously, the attempt to compile German dietary guidelines into a diet score was predominantly not successful with regards to preventing chronic diseases in the EPIC-Potsdam study. Current guidelines were supplemented by the latest evidence from systematic reviews and expert papers published between 2010 and 2020 on the prevention potential of food groups on chronic diseases such as type 2 diabetes, cardiovascular diseases and cancer. A diet score was developed by scoring the food groups according to a recommended low, moderate or high intake. The relative validity and reliability of the diet score, assessed by a food frequency questionnaire, was investigated. The consideration of current evidence resulted in 10 key food groups being preventive of the chronic diseases of interest. They served as components in the diet score and were scored from 0 to 1 point, depending on their recommended intake, resulting in a maximum of 10 points. Both the reliability (r = 0.53) and relative validity (r = 0.43) were deemed sufficient to consider the diet score as a stable construct in future investigations. This new diet score can be a promising tool to investigate dietary intake in etiological research by concentrating on 10 key dietary determinants with evidence-based prevention potential for chronic diseases.
KW  - diet score
KW  - dietary guidelines
KW  - food groups
KW  - chronic disease
KW  - type 2
KW  - diabetes
KW  - cardiovascular disease
KW  - cancer
KW  - prevention
KW  - reliability;
KW  - validity
Y1  - 2022
U6  - https://doi.org/10.3390/nu14112359
SN  - 2072-6643
VL  - 14
IS  - 11
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Mugele, Hendrik
A1  - Plummer, Ashley
A1  - Baritello, Omar
A1  - Towe, Maggie
A1  - Brecht, Pia
A1  - Mayer, Frank
T1  - Accuracy of training recommendations based on a treadmill multistage incremental exercise test
JF  - PLOS ONE
N2  - Competitive runners will occasionally undergo exercise in a laboratory setting to obtain predictive and prescriptive information regarding their performance. The present research aimed to assess whether the physiological demands of lab-based treadmill running (TM) can simulate that of over-ground (OG) running using a commonly used protocol. Fifteen healthy volunteers with a weekly mileage of ≥ 20 km over the past 6 months and treadmill experience participated in this cross-sectional study. Two stepwise incremental tests until volitional exhaustion was performed in a fixed order within one week in an Outpatient Clinic research laboratory and outdoor athletic track. Running velocity (IATspeed), heart rate (IATHR) and lactate concentration at the individual anaerobic threshold (IATbLa) were primary endpoints. Additionally, distance covered (DIST), maximal heart rate (HRmax), maximal blood lactate concentration (bLamax) and rate of perceived exertion (RPE) at IATspeed were analyzed. IATspeed, DIST and HRmax were not statistically significantly different between conditions, whereas bLamax and RPE at IATspeed showed statistical significance (p < 0.05). Apart from RPE at IATspeed, IATspeed, DIST, HRmax and bLamax strongly correlate between conditions (r = 0.815–0.988). High reliability between conditions provides strong evidence to suggest that running on a treadmill are physiologically comparable to that of OG and that training recommendations and be made with assurance.
KW  - individual anaerobic threshold
KW  - lactate threshold
KW  - soccer players
KW  - performance
KW  - validity
KW  - reliability
KW  - runners
Y1  - 2018
U6  - https://doi.org/10.1371/journal.pone.0204696
SN  - 1932-6203
VL  - 13
IS  - 10
SP  - 1
EP  - 12
PB  - PLOS
CY  - San Francisco
ER  - 
TY  - GEN
A1  - Mugele, Hendrik
A1  - Plummer, Ashley
A1  - Baritello, Omar
A1  - Towe, Maggie
A1  - Brecht, Pia
A1  - Mayer, Frank
T1  - Accuracy of training recommendations based on a treadmill multistage incremental exercise test
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2  - Competitive runners will occasionally undergo exercise in a laboratory setting to obtain predictive and prescriptive information regarding their performance. The present research aimed to assess whether the physiological demands of lab-based treadmill running (TM) can simulate that of over-ground (OG) running using a commonly used protocol. Fifteen healthy volunteers with a weekly mileage of ≥ 20 km over the past 6 months and treadmill experience participated in this cross-sectional study. Two stepwise incremental tests until volitional exhaustion was performed in a fixed order within one week in an Outpatient Clinic research laboratory and outdoor athletic track. Running velocity (IATspeed), heart rate (IATHR) and lactate concentration at the individual anaerobic threshold (IATbLa) were primary endpoints. Additionally, distance covered (DIST), maximal heart rate (HRmax), maximal blood lactate concentration (bLamax) and rate of perceived exertion (RPE) at IATspeed were analyzed. IATspeed, DIST and HRmax were not statistically significantly different between conditions, whereas bLamax and RPE at IATspeed showed statistical significance (p < 0.05). Apart from RPE at IATspeed, IATspeed, DIST, HRmax and bLamax strongly correlate between conditions (r = 0.815–0.988). High reliability between conditions provides strong evidence to suggest that running on a treadmill are physiologically comparable to that of OG and that training recommendations and be made with assurance.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 477 
KW  - individual anaerobic threshold
KW  - lactate threshold
KW  - soccer players
KW  - performance
KW  - validity
KW  - reliability
KW  - runners
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-419697
SN  - 1866-8364
IS  - 477
ER  - 
TY  - GEN
A1  - Dech, Silas
A1  - Bittmann, Frank
A1  - Schaefer, Laura
T1  - Assessment of the Adaptive Force of Elbow Extensors in Healthy Subjects Quantified by a Novel Pneumatically Driven Measurement System with Considerations of Its Quality Criteria
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2  - Adaptive Force (AF) reflects the capability of the neuromuscular system to adapt adequately to external forces with the intention of maintaining a position or motion. One specific approach to assessing AF is to measure force and limb position during a pneumatically applied increasing external force. Through this method, the highest (AFmax), the maximal isometric (AFisomax) and the maximal eccentric Adaptive Force (AFeccmax) can be determined. The main question of the study was whether the AFisomax is a specific and independent parameter of muscle function compared to other maximal forces. In 13 healthy subjects (9 male and 4 female), the maximal voluntary isometric contraction (pre- and post-MVIC), the three AF parameters and the MVIC with a prior concentric contraction (MVICpri-con) of the elbow extensors were measured 4 times on two days. Arithmetic mean (M) and maximal (Max) torques of all force types were analyzed. Regarding the reliability of the AF parameters between days, the mean changes were 0.31–1.98 Nm (0.61%–5.47%, p = 0.175–0.552), the standard errors of measurements (SEM) were 1.29–5.68 Nm (2.53%–15.70%) and the ICCs(3,1) = 0.896–0.996. M and Max of AFisomax, AFmax and pre-MVIC correlated highly (r = 0.85–0.98). The M and Max of AFisomax were significantly lower (6.12–14.93 Nm; p ≤ 0.001–0.009) and more variable between trials (coefficient of variation (CVs) ≥ 21.95%) compared to those of pre-MVIC and AFmax (CVs ≤ 5.4%). The results suggest the novel measuring procedure is suitable to reliably quantify the AF, whereby the presented measurement errors should be taken into consideration. The AFisomax seems to reflect its own strength capacity and should be detected separately. It is suggested its normalization to the MVIC or AFmax could serve as an indicator of a neuromuscular function.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 710 
KW  - adaptive force
KW  - neuromuscular functionality
KW  - sensorimotor control
KW  - isometric muscle action
KW  - eccentric muscle action
KW  - maximal voluntary contraction
KW  - adaptive holding capacity
KW  - reliability
KW  - validity
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-510950
SN  - 1866-8364
IS  - 710
ER  - 
TY  - JOUR
A1  - Dech, Silas
A1  - Bittmann, Frank
A1  - Schaefer, Laura
T1  - Assessment of the adaptive force of Elbow extensors in healthy subjects quantified by a novel pneumatically driven measurement system with considerations of its quality criteria
JF  - Diagnostics : open access journal
N2  - Adaptive Force (AF) reflects the capability of the neuromuscular system to adapt adequately to external forces with the intention of maintaining a position or motion. One specific approach to assessing AF is to measure force and limb position during a pneumatically applied increasing external force. Through this method, the highest (AFmax), the maximal isometric (AFisomax) and the maximal eccentric Adaptive Force (AFeccmax) can be determined. The main question of the study was whether the AFisomax is a specific and independent parameter of muscle function compared to other maximal forces. In 13 healthy subjects (9 male and 4 female), the maximal voluntary isometric contraction (pre- and post-MVIC), the three AF parameters and the MVIC with a prior concentric contraction (MVICpri-con) of the elbow extensors were measured 4 times on two days. Arithmetic mean (M) and maximal (Max) torques of all force types were analyzed. Regarding the reliability of the AF parameters between days, the mean changes were 0.31–1.98 Nm (0.61%–5.47%, p = 0.175–0.552), the standard errors of measurements (SEM) were 1.29–5.68 Nm (2.53%–15.70%) and the ICCs(3,1) = 0.896–0.996. M and Max of AFisomax, AFmax and pre-MVIC correlated highly (r = 0.85–0.98). The M and Max of AFisomax were significantly lower (6.12–14.93 Nm; p ≤ 0.001–0.009) and more variable between trials (coefficient of variation (CVs) ≥ 21.95%) compared to those of pre-MVIC and AFmax (CVs ≤ 5.4%). The results suggest the novel measuring procedure is suitable to reliably quantify the AF, whereby the presented measurement errors should be taken into consideration. The AFisomax seems to reflect its own strength capacity and should be detected separately. It is suggested its normalization to the MVIC or AFmax could serve as an indicator of a neuromuscular function.
KW  - adaptive force
KW  - sensorimotor control
KW  - isometric muscle action
KW  - eccentric muscle action
KW  - maximal voluntary contraction
KW  - adaptive holding capacity
KW  - reliability
KW  - validity
KW  - neuromuscular functionality
Y1  - 2021
U6  - https://doi.org/10.3390/diagnostics11060923
SN  - 2075-4418
VL  - 11
IS  - 6
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Tschorn, Mira
A1  - Rieckmann, Nina
A1  - Arolt, Volker
A1  - Beer, Katja
A1  - Haverkamp, Wilhelm
A1  - Martus, Peter
A1  - Waltenberger, Johannes
A1  - Müller-Nordhorn, Jacqueline
A1  - Ströhle, Andreas
T1  - Erkennungsgüte dreier deutschsprachiger Screeninginstrumente für Depression bei hospitalisierten Patienten mit koronarer Herzerkrankung
T1  - Diagnostic Accuracy of German Depression Screenings in Patients with Coronary Heart Disease
JF  - Psychiatrische Praxis
N2  - Ziel Vergleich der Erkennungsgüte von drei Depressions-Screeninginstrumenten bei Patienten mit koronarer Herzerkrankung (KHK).
Methodik 1019 KHK-Patienten erhielten den Patient Health Questionnaire (PHQ-9 und PHQ-2) und die Hospital Anxiety and Depression Scale (HADS-D) sowie ein klinisches Interview (Composite International Diagnostic Interview) als Referenzstandard.
Ergebnisse Bezüglich der Erkennungsgüte waren PHQ-9 und HADS-D dem PHQ-2 überlegen. Optimale Cut-off-Werte waren 7 (PHQ-9 und HADS-D) und 2 (PHQ-2).
Schlussfolgerung PHQ-9 und HADS-D haben eine vergleichbare Diskriminationsfähigkeit für depressive Störungen bei KHK-Patienten.
N2  - Objective To compare the diagnostic accuracy of German depression screening instruments in patients with coronary heart disease (CHD). Methods 1019 CHD patients completed the Patient Health Questionnaire (PHQ-9 and PHQ-2) and the Hospital Anxiety and Depression Scale (HADS-D). The Composite International Diagnostic Interview served as reference standard for "any depressive disorder" and "major depression". Results The accuracy of the PHQ-9 and the HADS-D was comparable according to the area under the curve, and both were superior to the PHQ-2. The optimal cut-off according to the Youden index (maximum sum of sensitivity and specificity) was 7 for both instruments. At this optimal cut-off, the PHQ-9 had a higher sensitivity compared to the HADS-D, but a lower specificity (below 68). Results remained similar when patients who reported that they currently underwent treatment for depression were excluded. Conclusion The PHQ-9 and the HADS-D have comparable overall diagnostic accuracy in CHD patients. In line with previous screening studies with CHD patients, the optimal cut-offs were below the cut-offs that are recommended in the literature.
KW  - coronary artery disease
KW  - depression
KW  - diagnosis
KW  - screening
KW  - validity
Y1  - 2019
U6  - https://doi.org/10.1055/s-0042-123434
SN  - 0303-4259
SN  - 1439-0876
VL  - 46
IS  - 1
SP  - 41
EP  - 48
PB  - Thieme
CY  - Stuttgart
ER  - 
TY  - JOUR
A1  - Müller, Steffen
A1  - Mayer, Patrizia
A1  - Baur, Heiner
A1  - Mayer, Frank
T1  - Higher velocities in isokinetic dynamometry a pilot study of new test mode with active compensation of inertia
JF  - Isokinetics and exercise science : official journal of the European Isokinetic Society
N2  - Isokinetic dynamometry is a standard technique for strength testing and training. Nevertheless reliability and validity is limited due to inertia effects, especially for high velocities. Therefore in a first methodological approach the purpose was to evaluate a new isokinetic measurement mode including inertia compensation compared to a classic isokinetic measurement mode for single and multijoint movements at different velocities.
 Isokinetic maximum strength measurements were carried out in 26 healthy active subjects. Tests were performed using classic isokinetic and new isokinetic mode in random order. Maximum torque/force, maximum movement velocity and time for acceleration were calculated. For inter-instrument agreement Bland and Altman analysis, systematic and random error was quantified. Differences between both methods were assessed (ANOVA alpha = 0.05).
 Bland and Altman analysis showed the highest agreement between the two modes for strength and velocity measurements (bias: < +/- 1.1%; LOA: < 14.2%) in knee flexion/extension at slow isokinetic velocity (60 degrees/s). Least agreement (range: bias: -67.6% +/- 119.0%; LOA: 53.4% 69.3%) was observed for shoulder/arm test at high isokinetic velocity (360 degrees/s). The Isokin(new) mode showed higher maximum movement velocities (p < 0.05).
 For low isokinetic velocities the new mode agrees with the classic mode. Especially at high isokinetic velocities the new isokinetic mode shows relevant benefits coupled with a possible trade-off with the force/torque measurement. In conclusion, this study offers for the first time a comparison between the 'classical' and inertia-compensated isokinetic dynamometers indicating the advantages and disadvantages associated with each individual approach, particularly as they relate to medium or high velocities in testing and training.
KW  - Strength testing
KW  - concentric
KW  - validity
KW  - trunk
KW  - knee
KW  - shoulder
Y1  - 2011
U6  - https://doi.org/10.3233/IES-2011-0398
SN  - 0959-3020
VL  - 19
IS  - 2
SP  - 63
EP  - 70
PB  - IOS Press
CY  - Amsterdam
ER  - 
TY  - GEN
A1  - Lesinski, Melanie
A1  - Schmelcher, Alina
A1  - Herz, Michael
A1  - Puta, Christian
A1  - Gabriel, Holger
A1  - Arampatzis, Adamantios
A1  - Laube, Gunnar
A1  - Büsch, Dirk
A1  - Granacher, Urs
T1  - Maturation-, age-, and sex-specific anthropometric and physical fitness percentiles of German elite young athletes
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2  - The aim of this study was to establish maturation-, age-, and sex-specific anthropometric and physical fitness percentile reference values of young elite athletes from various sports. Anthropometric (i.e., standing and sitting body height, body mass, body mass index) and physical fitness (i.e., countermovement jump, drop jump, change-of-direction speed [i.e., T-test], trunk muscle endurance [i.e., ventral Bourban test], dynamic lower limbs balance [i.e., Y-balance test], hand grip strength) of 703 male and female elite young athletes aged 8–18 years were collected to aggregate reference values according to maturation, age, and sex. Findings indicate that body height and mass were significantly higher (p<0.001; 0.95≤d≤1.74) in more compared to less mature young athletes as well as with increasing chronological age (p<0.05; 0.66≤d≤3.13). Furthermore, male young athletes were significantly taller and heavier compared to their female counterparts (p<0.001; 0.34≤d≤0.50). In terms of physical fitness, post-pubertal athletes showed better countermovement jump, drop jump, change-of-direction, and handgrip strength performances (p<0.001; 1.57≤d≤8.72) compared to pubertal athletes. Further, countermovement jump, drop jump, change-of-direction, and handgrip strength performances increased with increasing chronological age (p<0.05; 0.29≤d≤4.13). In addition, male athletes outperformed their female counterpart in the countermovement jump, drop jump, change-of-direction, and handgrip strength (p<0.05; 0.17≤d≤0.76). Significant age by sex interactions indicate that sex-specific differences were even more pronounced with increasing age. Conclusively, body height, body mass, and physical fitness increased with increasing maturational status and chronological age. Sex-specific differences appear to be larger as youth grow older. Practitioners can use the percentile values as approximate benchmarks for talent identification and development.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 662 
KW  - biological maturation
KW  - reliability
KW  - validity
KW  - performance
KW  - physiology
KW  - maturity
KW  - injury
KW  - talent
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-480268
SN  - 1866-8364
IS  - 662
ER  - 
TY  - JOUR
A1  - Lesinski, Melanie
A1  - Schmelcher, Alina
A1  - Herz, Michael
A1  - Puta, Christian
A1  - Gabriel, Holger
A1  - Arampatzis, Adamantios
A1  - Laube, Gunnar
A1  - Büsch, Dirk
A1  - Granacher, Urs
T1  - Maturation-, age-, and sex-specific anthropometric and physical fitness percentiles of German elite young athletes
JF  - Plos One
N2  - The aim of this study was to establish maturation-, age-, and sex-specific anthropometric and physical fitness percentile reference values of young elite athletes from various sports. Anthropometric (i.e., standing and sitting body height, body mass, body mass index) and physical fitness (i.e., countermovement jump, drop jump, change-of-direction speed [i.e., T-test], trunk muscle endurance [i.e., ventral Bourban test], dynamic lower limbs balance [i.e., Y-balance test], hand grip strength) of 703 male and female elite young athletes aged 8–18 years were collected to aggregate reference values according to maturation, age, and sex. Findings indicate that body height and mass were significantly higher (p<0.001; 0.95≤d≤1.74) in more compared to less mature young athletes as well as with increasing chronological age (p<0.05; 0.66≤d≤3.13). Furthermore, male young athletes were significantly taller and heavier compared to their female counterparts (p<0.001; 0.34≤d≤0.50). In terms of physical fitness, post-pubertal athletes showed better countermovement jump, drop jump, change-of-direction, and handgrip strength performances (p<0.001; 1.57≤d≤8.72) compared to pubertal athletes. Further, countermovement jump, drop jump, change-of-direction, and handgrip strength performances increased with increasing chronological age (p<0.05; 0.29≤d≤4.13). In addition, male athletes outperformed their female counterpart in the countermovement jump, drop jump, change-of-direction, and handgrip strength (p<0.05; 0.17≤d≤0.76). Significant age by sex interactions indicate that sex-specific differences were even more pronounced with increasing age. Conclusively, body height, body mass, and physical fitness increased with increasing maturational status and chronological age. Sex-specific differences appear to be larger as youth grow older. Practitioners can use the percentile values as approximate benchmarks for talent identification and development.
KW  - biological maturation
KW  - reliability
KW  - validity
KW  - performance
KW  - physiology
KW  - maturity
KW  - injury
KW  - talent
Y1  - 2020
U6  - https://doi.org/10.1371/journal.pone.0237423
SN  - 1932-6203
VL  - 15
IS  - 8
PB  - Plos One
CY  - San Francisco, California
ER  - 
TY  - JOUR
A1  - Kohler, Ulrich
A1  - Kreuter, Frauke
A1  - Stuart, Elizabeth A.
T1  - Nonprobability Sampling and Causal Analysis
JF  - Annual review of statistics and its application
N2  - The long-standing approach of using probability samples in social science research has come under pressure through eroding survey response rates, advanced methodology, and easier access to large amounts of data. These factors, along with an increased awareness of the pitfalls of the nonequivalent comparison group design for the estimation of causal effects, have moved the attention of applied researchers away from issues of sampling and toward issues of identification. This article discusses the usability of samples with unknown selection probabilities for various research questions. In doing so, we review assumptions necessary for descriptive and causal inference and discuss research strategies developed to overcome sampling limitations.
KW  - causal inference
KW  - generalizability
KW  - self-selection
KW  - nonprobability sampling
KW  - validity
KW  - measurement error
KW  - heterogeneous treatment effects
KW  - big data
Y1  - 2018
U6  - https://doi.org/10.1146/annurev-statistics-030718-104951
SN  - 2326-8298
SN  - 2326-831X
VL  - 6
SP  - 149
EP  - 172
PB  - Annual Reviews
CY  - Palo Alto
ER  -