Gatorade as "nutrition" is laughable just as you describe it.
Gatorade, "energy drinks", and soda pops along with the sugar beverage industry are hugely supporting the white coats' income stream. Sugar is one of the next "Cigarettes" scandals of corporate denial. Cigarette makes knew smoking accelerates chronic bad health and death. That was and still is a boon to the white coats.
Gatorade is real poor nutrition for sport... 8 oz has 14g sugar... everyone drinks a 32 oz dose during sport... maybe several. That is 56 grams sugar per 32 oz bottle... frequently on sale for a USD 1 or so...
Energy drink worse... 25g sugar per 8 oz... usually comes in 16 oz can... 50 g sugar per can... my Soldiers in warm climates drank 2-3 of those BEFORE LUNCH... that is 100-150 gr of sugar...
All that excess sugar over time wrecks your body and health in numerous ways. That is another way sugar industry is a friend to white coats pocketbooks. Not just once, but continually.
Enough of the sugar trip, or our USA food supply as a whole.
When I say doctors do not know much about nutrition, I am serious. As a whole, in USA, they get maybe a few hrs training on it. Our grandmothers and their mothers knew the importance of why and how to maintain an immune system. They knew how to make food to achieve that. It is almost forgotten in USA.
When I say follow the money... look at where the majority of expenditures for medical costs go... they go towards dealing with what are mostly conditions created by man... then how conditions are kept to make this repeatable and progressively more expensive and who is paying how much... there is a lot of motivation to keep the gravy trail rolling and get bigger.
Enough of that stuff too.
If a player several days out does not do a good job of managing rest, hydration, nutrition and on match day does a poor job nutrition, hydration, mineral balance... player is gunna get rekt.