Describe why macronutrients are important to the energy systems and how much energy is produced from their breakdown.

Introduction (@ 600 words): Your introduction should briefly describe the athlete paying specific attention to the physiological demands of the sport (intensity, duration etc). Present your calculations of estimated daily calorie requirements here.
Main body (@ 1200 words): The body of the essay is where you set out your main argument. It should have a narrative flow that highlights the sequence of the different points in your argument/discussion. Introduce all of the energy systems that you think are important to elite marathon running and justify why you think they are important. Use peer reviewed journal articles to illustrate the physiological demands of the sport. Describe why macronutrients are important to the energy systems and how much energy is produced from their breakdown. State the percentage contribution of macronutrients to the performance diet for an elite marathon runner and calculate the quantity of carbohydrate, fat and protein required that should be consumed.
Conclusion (@ 300 words): The conclusion should summarise the issues that you have raised in the body of your assignment and tie up any loose ends in your argument/discussion. It should emphasise the key elements of your essay and it is often a good idea to refer once again to the question title.
Please note that you should not use the components of an essay (introduction, main body and conclusion) as headings within your essay. As in all written assignments, you should support your answer with referencing
NB. It is strongly advised that clear graphs are presented to supplement the written information but make sure you refer to the images to support your arguments.