Comparison of step-count outcomes across seven different activity trackers: a free-living experiment with young and older adults. - Nakagata, Takashi; Yamada, Yosuke; Taniguchi, Masashi; Nanri, Hinako; Kimura, Misaka; Miyachi, Motohiko; Ono, Rei (BMC Sports Science, Medicine & Rehabilitation, 2024)