MARNI SUMBAL, MS, RD, CSSD, LD/N, holds a master's degree in exercise physiology and is a board-certified sport dietitian. Her books include Essential Sports Nutrition and The 365-day Running Journal. She helps athletes prepare through Trimarni Coaching and Nutrition. Marni has completed 16 Ironman-distance triathlons (including the Ironman World Championship in Kona, Hawaii).
