Physical activity monitors to enhance amount of physical activity in older adults - a systematic review and meta-analysis.

"Competing interests The authors declare that they have no competing interests."

"Funding The content presented within this paper was produced as part of the project REACH: this project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 690425 [1, 54]."

"This systematic review and meta-analysis is detailed according to the recommendations of the Cochrane Handbook [] and it is reported according to the PRISMA statement. The method is described in the published review protocol as well as in the PROSPERO registration (CRD42018083648) [, ]. Unless otherwise stated, the methods used and reported in this systematic review followed the review protocol. PROSPERO registration: CRD42018083648."