Cardiorespiratory fitness and free-living physical activity are not associated with cognition in persons with progressive multiple sclerosis: Baseline analyses from the CogEx study

Brian M. Sandroff, Robert W. Motl, Maria Pia Amato, Giampaolo Brichetto, Jeremy Chataway, Nancy D. Chiaravalloti, Gary R. Cutter, Ulrik Dalgas, John DeLuca, Rachel Farrell, Peter Feys, Massimo Filippi, Jennifer Freeman, Matilde Inglese, Cecilia Meza, Maria A. Rocca, Amber Salter, Anthony Feinstein