Mary is a 57, 135 pound 45 year old recreational marathon runner. She has read that a high fat diet is the way to go for endurance athletes understanding there is an almost unlimited supply of adipose tissue that can be used for energy. She has been training for several months for an upcoming marathon that is only 2 weeks away and has just started following a lower carbohydrate high fat diet to tap into her fat burning potential. She reports feeling tired and sluggish and is having a hard time doing her training runs and is asking what she should do?

1. Understanding intensity and duration in relation to energy substrate utilization does the theory of eating a high fat controlled carbohydrate (lower carb) diet show benefits for certain athletes like Mary? Why or why not? What would be your nutrition recommendations for Mary moving forward and why would you give these specific recommendations? Provide an example meal plan including grams of carbohydrate, fat and protein.