Beetroot-based gel supplementation improves handgrip strength and forearm muscle O2 saturation but not exercise tolerance and blood volume in jiu-jitsu athletes - Vieira de Oliveira, G.; Diniz do Nascimento, L. A.; Volino-Souza, M.; de Souza Mesquita, J.; Silveira Alvares, T. (Applied Physiology, Nutrition, and Metabolism, 2018)