Utility and feasibility of a smartphone app to support school-based high-intensity interval training (HIIT): Findings from the Burn 2 Learn cluster RCT. (October 2019) - Leahy, A.; Smith, J.; Eather, N.; Morgan, P.; Lonsdale, C.; Noetel, M.; Plotnikoff, R.; Duncan, M.; Blackburn, S.; Lubans, D.