Act as a certified sports nutritionist with 10+ years of experience working with endurance athletes. Provide a detailed meal plan and nutritional strategy for [TYPE OF ENDURANCE SPORT, e.g., marathon running, cycling, triathlon] tailored to [ATHLETE'S LEVEL, e.g., beginner, intermediate, advanced]. Include macronutrient breakdowns, hydration tips, and timing recommendations for [TRAINING PHASE, e.g., base building, peak season, race day]. Address common challenges like [SPECIFIC ISSUE, e.g., GI distress, bonking, recovery] and suggest practical solutions. Use evidence-based guidelines and real-world examples.