Thanks for the nice summary of your tennis camp training.
The USTA sports science section has this summary on nutrition - what do you think of it?
"Nutrition: Performance Diet Principles for Competitive Tennis
By Page Love, MS, RD
1. Drink, Drink, Drink! Drink at least 80 oz. of hydrating fluids per day. Drink before you get thirsty. Replace a liter/hour during play. Sports beverages or water are best on the court; juices, milk, and any other decaffeinated beverages are fine during the day. Sports beverages at 6 - 7% absorb quickly from the stomach during match play, i.e. Gatorade. Fruit juices and sodas should be avoided on the court because of the high sugar concentration. Try to drink before you get thirsty!
2. Do not starve the muscles of fuel! Eating at least 8-10 servings per day from complex carbohydrate choices will create the base to maintain your muscle glycogen levels. Choose higher fiber options whenever possible - cereals, bread, rice, pasta, etc. Seven a day from fruits and vegetables will meet extra carbohydrate, mineral, and additional fluid needs from food. Choose a wide variety of colors and types of fruits and vegetables daily - something citrus, something deep green, and at least one other red, yellow, or orange choice. Divide these foods into 5-6 small meals.
3. Eat breakfast everyday! After a ten to twelve hour overnight fast your muscle energy levels are low. It is unfair to expect yourself to perform at a peak without refueling with carbohydrate sources. Many traditional breakfast choices are appropriate choices, i.e. low sugar breakfast cereal, two slices of toast, glass of juice; or, pancakes or waffles, small amount of syrup, fresh fruit, 8 oz. of skim milk. Even if you have not been eating breakfast, try eating a bagel and juice in your car on the way to the court. Starting to eat something again will help to rejuvenate you hunger levels in the morning.
4. Provide the building blocks of muscle tissue everyday! Complete protein sources like turkey, chicken, tuna, tenderloin, and fresh lean deli meats are needed at at least 4-6 oz. amounts during the day. Choose alternative protein options to meet additional protein needs such as low fat milk, cheese, and cottage cheese, light peanut butter, beans, or tofu at smaller meals to aid in satiety and fullness."
It supposedly takes the body a full two weeks to adapt to the heat:
Is this pretty much what you found?