To cite arctools in publications use:

Karas, M., Schrack, J., and Urbanek, J. (2021). arctools: Processing and Physical Activity Summaries of Minute Level Activity Data. R package version 1.1.4.

Corresponding BibTeX entry:

  @Manual{,
    title = {{arctools: Processing and Physical Activity Summaries of
      Minute Level Activity Data}},
    author = {Marta Karas and Jennifer Schrack and Jacek Urbanek},
    url = {https://CRAN.R-project.org/package=arctools},
    note = {R package version 1.1.4},
    year = {2021},
  }