Janis Fiedler's Avatar

Janis Fiedler

@fiejanis.bsky.social

PostDoc @KIT | wearable technology and mHealth Behavior Change | Exercise Physiology | enthusiastic R amateur | Views are my own https://orcid.org/0000-0002-9291-2191

1,063 Followers  |  490 Following  |  117 Posts  |  Joined: 02.10.2023
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Posts by Janis Fiedler (@fiejanis.bsky.social)

TrΓ€umchen :D
Bei uns ist ein Lichtschalter so verkabelt, dass der Staubsauger angeht wenn man ihn drΓΌckt (da der Schalter die Steckdose darunter und nicht das Licht regelt).

16.12.2025 13:54 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
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A Refined #Mobile #Health Intervention (SMARTFAMILY2.0) to Promote #PhysicalActivity and Healthy Eating in a Family Setting: Randomized Controlled Trial Background: Many #Mobile #Health (#mHealth) apps focus on promoting #PhysicalActivity (PA) and healthy eating (HE). However, there is limited empirical evidence regarding their effectiveness in initiating and sustaining behavior change, particularly among children and adolescents. Considering that behavior is influenced by social contexts, it is essential to take core settings like family dynamics into account when designing #mHealth apps. Objective: The purpose of this study was to further develop and refine the SMARTFAMILY (SF) #App targeting PA and HE in a collective family-based setting by enhancing design and usability, as well as by adding gamification aspects, #Health literacy, and just-in-time adaptive interventions to the first version of the #App. Methods: The SF2.0 #App, based on behavior change theories and techniques, was developed, implemented, and evaluated. The #App was used in a collective family setting, with family members using it individually and cooperatively. In a cluster-randomized controlled trial, the intervention group (IG) used the #App for 3 consecutive weeks, while the control group (CG) received no treatment. Primary outcomes included PA measured through self-reports and accelerometry, as well as self-reported fruit and vegetable intake (FVI) for HE. Secondary outcomes included intrinsic motivation, behavior-specific self-efficacy, and the Family #Health Climate. A follow-up assessment (T2) was conducted 4 weeks after the postmeasurement (T1) to assess intervention effects. Multilevel analyses were performed in R (R Foundation for Statistical Computing), considering the hierarchical structure of individuals (level 1) within families (level 2). Results: Overall, 55 families (28 CG, 105/209; 27 IG, 104/209 participants) were recruited for the study. In total, 3 families (3 CG, n=12) chose to drop out of the study due to personal reasons before T0. Overall, no evidence for meaningful and statistically significant increases in PA was observed in favor of the IG of our physically active sample. However, the #App elucidated positive effects in favor of the IG for FVI diary (T0-T1; P=.03), joint PA (T0-T1; P=.02 and T0-T2; P

New in JMIR mhealth: A Refined #Mobile #Health Intervention (SMARTFAMILY2.0) to Promote #PhysicalActivity and Healthy Eating in a Family Setting: Randomized Controlled Trial

15.12.2025 19:32 β€” πŸ‘ 2    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0
This picture shows a family of four around a smartphone with a screenshot of the SMARTFAMILY App.

This picture shows a family of four around a smartphone with a screenshot of the SMARTFAMILY App.

πŸ§ͺ Publication alert!
Results of the SMARTFAMILY2.0 #mHealth study show:
- no effect on physical activity in already active families
- increase fruit & veggie intake, joint family activities, and shared meals.

OA: doi.org/10.2196/65558

#DigitalHealth #FamilyHealth #BehaviorChange #RCT

16.12.2025 09:01 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
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#Conference Time

Last week our members Marco Giugiu, @fiejanis.bsky.social and @irinatimm.bsky.social presented our Wearable Landscape initiative at the International Symposium on Physical Behaviors πŸ‹οΈ, Wearable Sensing ⌚️, and Health Analytics 🩺.

Thanks to @tu-dortmund.de for hosting this event.

01.12.2025 14:46 β€” πŸ‘ 2    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0
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Data Visualisation Gallery Gallery of data visualisations created by Nicola Rennie.

One of the things that has been on my to do list for a very long time, is building a gallery of all of the charts I've made across #TidyTuesday, #30DayChartChallenge, #30DayMapChallenge, and other miscellaneous projects πŸ“Š

And it's finally here!

Link: nrennie.rbind.io/viz-gallery/

#DataViz #RStats

26.11.2025 13:32 β€” πŸ‘ 111    πŸ” 18    πŸ’¬ 6    πŸ“Œ 3

sounds like the review the autism paper would have deserved...
bsky.app/profile/jack...

27.11.2025 10:47 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

this is one of my favourite observations about sample size calculations. (afaik first articulated by Miettinen in 1985)

25.11.2025 10:56 β€” πŸ‘ 77    πŸ” 21    πŸ’¬ 1    πŸ“Œ 2
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Warum KΓΌnstliche Intelligenz nicht als Suchmaschine taugt Die HΓ€lfte der Deutschen verwendet mittlerweile ChatGPT & Co. als Google-Ersatz. Gleichzeitig arbeiten auch die klassischen Suchmaschinen immer mehr mit KI. Warum das ein Problem ist. Von Till BΓΌcker.

"Schaut man rein auf die Korrektheit der Antworten, beinhaltet ChatGPT zu 51,5 Prozent, Copilot zu 45,4 Prozent, Gemini zu 50 Prozent und Perplexity zu 45,7 Prozent wesentliche Fehler oder Ungenauigkeiten."
www.tagesschau.de/wirtschaft/d...

24.11.2025 11:54 β€” πŸ‘ 409    πŸ” 151    πŸ’¬ 33    πŸ“Œ 10
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#MemberMonday

Insights from last week’s Wearable Landscape meeting: a big thanks to our core members and supporting students for weekly developing the initiative β€” and (of course) having some fun along the way :)

Let’s keep building our living network! πŸŒπŸ’‘

#Wearables #OpenScience #Collaboration

20.10.2025 08:17 β€” πŸ‘ 1    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0

man kΓΆnnte auch ein bisschen umschreiben und statt geht vieles, gehen viele schreiben...

07.10.2025 07:12 β€” πŸ‘ 2    πŸ” 1    πŸ’¬ 1    πŸ“Œ 0
W 2-Professur fΓΌr Politische Psychologie (m/w/d)

Exciting new job in Landau 🀩 We’re searching for a Professor of Political
Psychology (W2). Very much looking forward to your applications – if you
have any questions, please reach out to me. jobs.rptu.de/jobposting/3...

25.09.2025 13:59 β€” πŸ‘ 14    πŸ” 12    πŸ’¬ 0    πŸ“Œ 1
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Measurement properties of activity monitoring for a rehabilitation (AMoR) platform in post-stroke individuals in a simulated home environment The aim of this study was to evaluate the measurement properties of activity monitoring for a rehabilitation (AMoR) platform for step counting, time spent in sedentary behavior, and postural change...

Can someone help me to find the full text of this?
doi.org/10.1080/1074...

I checked all my available ressources plus messaged the authors and need it for a systematic review.

@academic-chatter.bsky.social @healthpsychology.bsky.social #behSci #SportScience #AcademicSky πŸ§ͺ

26.09.2025 07:41 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
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πŸŽ“I'm thrilled to share that I've successfully defended my doctoral dissertation on July 25, 25. I want to extend my heartfelt gratitude to my esteemed supervisors, Dr. Marco Giurgiu & Prof. Markus Reichert & Prof. Uli Ebner-Priemer, for their invaluable guidance and support πŸ™ @mhealthlab.bsky.social

02.08.2025 05:29 β€” πŸ‘ 6    πŸ” 3    πŸ’¬ 0    πŸ“Œ 0
Open science contributes to more rigorous and impactful science. However, little attention is often paid to the benefits that it provides to its users, such as project management and programming skills. Although not its primary objective, these skills may be considered additional benefits supporting the transition to open science practices. Drawing from international perspectives, this chapter will discuss skills that students develop explicitly or implicitly by engaging in open science and their benefits to careers within and outside of academia. It will also showcase examples of how engagement in open science is considered in (academic) hiring decisions, including ongoing debates and areas for (structural) improvement. Ultimately, this chapter will inform educators about the most important open science skills and provide insights into how to strategically build a resume to present open science-related skills convincingly to improve employability, including practical tips and resources.

Open science contributes to more rigorous and impactful science. However, little attention is often paid to the benefits that it provides to its users, such as project management and programming skills. Although not its primary objective, these skills may be considered additional benefits supporting the transition to open science practices. Drawing from international perspectives, this chapter will discuss skills that students develop explicitly or implicitly by engaging in open science and their benefits to careers within and outside of academia. It will also showcase examples of how engagement in open science is considered in (academic) hiring decisions, including ongoing debates and areas for (structural) improvement. Ultimately, this chapter will inform educators about the most important open science skills and provide insights into how to strategically build a resume to present open science-related skills convincingly to improve employability, including practical tips and resources.

#OpenScience principles help students gain lots of useful skills that are an advantage on the job market in and beyond academia. Read our latest book chapter where we provide tips for educators to bolster employability through open science: doi.org/10.31219/osf...

03.07.2025 05:15 β€” πŸ‘ 50    πŸ” 27    πŸ’¬ 3    πŸ“Œ 3
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Reference standards for power at fixed and individual anaerobic lactate thresholds for cycle ergometry throughout the Lifespan (14-64 years) in Germany: Pooled results of the KiGGS wave 2 and DEGS1 St... Hosted on the Open Science Framework

Authors: M. Thron, S. Altmann, S. HΓ€rtel, F. Barsch, L. Schlenker, S. Krug, K. BΓΆs, A. Woll

Data were pooled from the representative KiGGS wave 2 and DEGS1 study from the Robert Koch Institute.
πŸ”¬ Access the data: osf.io/u8h9b/

23.06.2025 05:38 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
Displayed are the centile curves at different percentiles for relative and absolute power at the individual lactate threshold.

Displayed are the centile curves at different percentiles for relative and absolute power at the individual lactate threshold.

πŸ“Š New Publication!
We analyzed 5000+ cycle ergometer tests (ages 14-64) to create reference standards of lactate thresholds for health studies and clinical practice.

Full text: doi.org/10.1080/0264...
#Exercise #SportsScience πŸ§ͺ

23.06.2025 05:38 β€” πŸ‘ 14    πŸ” 3    πŸ’¬ 1    πŸ“Œ 1

I feel you. And getting up is just the follow-up. It never ceases to amaze me how fast the little ones progress. If I'd learn in a year what they learn in a day I'd be happy :D

04.06.2025 11:38 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0
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#MemberMonday Recap

The past seven weeks introduced each member of our Management Group. A huge thank you to Marco Giurgiu, @fiejanis.bsky.social, @irinatimm.bsky.social, Simon Woll, Til Becker, Doreen Wohlfahrt and @clendt.bsky.social for your contribution to Wearable Landscape!

#academicsky πŸ§ͺ

02.06.2025 11:48 β€” πŸ‘ 5    πŸ” 2    πŸ’¬ 0    πŸ“Œ 0

Happy to be on board! Go check out @wearable-landscape.bsky.social if you haven’t already!

26.05.2025 08:46 β€” πŸ‘ 2    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0

Manchmal ist es wirklich schwierig die Lehre zu fΓΌllen.

26.05.2025 06:36 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
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#MemberMonday
Doreen Wohlfarth is a research assistant at @kit.edu . She is involved in various projects at the Sports Institute, with her current focus on the Wearable Landscape project. Here she supports our Living Review and other important publications.

#SportScience #BehSci #AcademicSky πŸ§ͺ

19.05.2025 07:05 β€” πŸ‘ 3    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0

crtl a, delete, yes

here is the workflow I used. Hope it helps :)

16.05.2025 11:35 β€” πŸ‘ 5    πŸ” 1    πŸ’¬ 0    πŸ“Œ 1

I need help. My day only has 1 meeting, and all emails are done. How does this research thing work again?
πŸ§ͺ #AcademicSky

16.05.2025 06:11 β€” πŸ‘ 14    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Thanks to everybody who chimed in!

I arrived at the conclusion that (1) there's a lot of interesting stuff about interactions and (2) the figure I was looking for does not exist.

So, I made it myself! Here's a simple illustration of how to control for confounding in interactions:>

11.05.2025 05:34 β€” πŸ‘ 1127    πŸ” 273    πŸ’¬ 67    πŸ“Œ 18
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#MemberMonday
Til Becker is a student assistant researcher at the Karlsruhe Institute of Technology ( @kit.edu ) during his master's degree. He sees the Wearable Landscape as great opportunity to improve his own competences and the field of wearables.

#SportScience #BehSci #AcademicSky πŸ§ͺ

12.05.2025 07:30 β€” πŸ‘ 3    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0

🌱 This project is 100% non-commercial & driven by passion.
We believe science should be accessible, connected & efficient.
If you're working on, or interested in, wearable validationβ€”follow along & join us!

07.05.2025 09:25 β€” πŸ‘ 2    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0

πŸ’‘ There is even more:
We’re building a collaborative space for the scientific community to...
...share validation protocols
...coordinate studies
...pool equipment
...analyze data together
Let’s reduce redundancy & work smarter. #ResearchNetwork #OpenScience

07.05.2025 09:25 β€” πŸ‘ 1    πŸ” 1    πŸ’¬ 1    πŸ“Œ 0
Wearable Landscape - Wearable Landscape

πŸ” What is Wearable Landscape?
An open-science project aiming to foster collaboration in the field of #Wearables. We want to bring experts together, to ultimately advance the validation and application in wearables that track 24-hour physical behavior (sleep, sedentary time, activity) #OpenScience

07.05.2025 09:25 β€” πŸ‘ 2    πŸ” 1    πŸ’¬ 1    πŸ“Œ 0

If you want to improve your performance sure.

30.04.2025 10:11 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Did they control for owning a Rolex?

29.04.2025 09:33 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0