While the benefits of physical activity for healthy aging are widely recognized, it is currently unknown whether specific types of activities are more beneficial than others. This project aims to improve our understanding of mechanisms by which different components of physical activity are associated with health outcomes in older adults. Although physical activity is likely to decline during aging, there may be variation across different components of physical activity (intensity, strength, tension, and rotational movements). In this project, we aim to identify trajectories of physical activity components that are optimal for healthy aging and to investigate how these trajectories may differ across subgroups. Ultimately, the findings of this project could lead to the development of personalized physical activity recommendations that can stimulate healthy aging for all individuals.
From a methodological point of view, it is a challenge to analyze (heterogeneity of) physical activity in older adults over time. The current project provides the ideal setting to investigate how longitudinal trajectories of different physical activities in older adults can be compared and assessed. Secondly, physical performance measures may play an important mediating role in the association between physical activity and other health outcomes. This has been demonstrated cross-sectionally, but not yet studied longitudinally.

Your duties
As a PhD candidate you will be responsible for conducting this research and performing the data analysis, writing of scientific articles and writing a dissertation. You will be able to use already collected data of the Longitudinal Aging Study Amsterdam, a cohort study in Dutch older men and women with more than 30 years of follow-up (LASA, www.lasa-vu.nl). Additionally, you will contribute to ongoing research activities within the LASA cohort study.

Your specific tasks are:

• To identify longitudinal trajectories of physical activities in older adults
• To investigate longitudinal trajectories of physical activities in relation to different health outcomes
• To develop and compare different methodological analysis techniques for analyzing complicated longitudinal data
• To disseminate the research findings through international scientific publications and a final thesis
• To present your findings at national and international conferences and symposia
• To contribute to teaching activities of the Department of Health Sciences

• A master's degree in Health Sciences, Public Health, Epidemiology, or related field
• Good knowledge and skills in methodology and statistics
• Experience with statistical software such as R and STATA is preferred
• Excellent command of spoken and written Dutch and English
• Well-developed analytical skills, intellectually curious, and eager to learn
• Able and willing to work both independently and collaboratively in a multidisciplinary context

Fixed-term contract: 1 year.

A exciting PhD position in a socially involved organization. The salary will be in accordance with university regulations for academic personnel and amounts €2,541 (PhD) per month during the first year and increases to €3,247 (PhD) per month during the fourth year, based on a full-time employment. The job profile is based on the university job ranking system and is vacant for 1 FTE.

The appointment will initially be for 1 year. After a satisfactory evaluation of the initial appointment, the contract will be extended for a total duration of 4 years. At the end of the fourth year, the employment contract is concluded with a dissertation.

Additionally, Vrije Universiteit Amsterdam offers excellent fringe benefits and various schemes and regulations to promote a good work/life balance, such as:

• a maximum of 41 days of annual leave based on full-time employment,
• 8% holiday allowance and 8.3% end-of-year bonus,
• discount on (and occasionally exclusive access to) theater performances and courses at the Griffioen Cultural Center,
• a wide range of sports facilities which staff may use at a modest charge,
• space for personal development

Vrije Universiteit Amsterdam

The ambition of Vrije Universiteit Amsterdam is clear: to contribute to a better world through outstanding education and ground-breaking research. We strive to be a university where personal development and commitment to society play a leading role. A university where people from different disciplines and backgrounds collaborate to achieve innovations and to generate new knowledge. Our teaching and research encompass the entire spectrum of academic endeavor - from the humanities, the social sciences and the natural sciences through to the life sciences and the medical sciences.

Vrije Universiteit Amsterdam is home to more than 30,000 students. We employ over 5,500 individuals. The VU campus is easily accessible and located in the heart of Amsterdam's Zuidas district, a truly inspiring environment for teaching and research.

Diversity
We are an inclusive university community. Diversity is one of our most important values. We believe that engaging in international activities and welcoming students and staff from a wide variety of backgrounds enhances the quality of our education and research. We are always looking for people who can enrich our world with their own unique perspectives and experiences.

The Faculty of Science
Working at the Faculty of Science means working together with students, PhD candidates and scientists who are focused on their discipline, yet also have a broad view of the world. We are proud of the collegial working environment within the faculty, which is characterised by an ambitious and pragmatic attitude with commitment to the bigger picture. At the Faculty of Science, scientists and students work on fundamental and complex social issues for a sustainable and healthy future. From forest fires to big data, from obesity to malnutrition, from genetics to pharmaceuticals and from molecules to the moon: our teaching and research cover the full breadth of the natural sciences. Scientific teaching and research is highly experimental, technical, computational and interdisciplinary in nature. This is why we collaborate extensively with leading research institutes and industry. The faculty has over 11,000 students studying across 40 educational programmes and employs over 1,600 staff spread over 10 scientific departments, making us the largest science faculty in the Netherlands.

About the department
The Department of Health Sciences offers inspiring education and conducts engaged research to improve population health. Specifically, the department focuses on the following research topics: prevention, nutrition, youth and lifestyle, infectious disease epidemiology, musculoskeletal health, and health technology assessment