It may not look like it, but atttending Fashion Week is hard work. Waiting in long lines with self-important people gets awfully hot, and repeated air-kissing takes more energy than you might imagine. Attending upwards of six shows a day -- often all over town -- then hitting parties at night, shouting above the noise to be heard, is exhausting.

Luckily, there are always sponsors at the Mercedes-Benz Fashion Week tents at Bryant Park eager to provide refreshment. After all, what could be better advertising than hundreds of beautiful women and men dressed to the nines, walking down the street with a given beverage in their hands?

Here's a look at some of the drinks being handed out with abandon inside the tents:

O.N.E. Water
Declared as the "official water sponsor of Mercedes-Benz Fashion Week" this water is packaged in aseptic packaging, which is recyclable. No caffeine here, but definitely the best pure hydration bet. Bonus: No calories! Not only are there big barrels of this water all around the tent lobby, but staff and volunteers hand a water box to you on the way in and out of shows.

O.N.E. Water profits help to support efforts to provide clean, drinkable water around the world. O.N.E. also prides itself on its environmental commitment, and in fact there are recycling bins around the tents. But, please, fashion people, stop leaving dozens of these half-empty cartons on the chairs and floors when you leave a show -- it just doesn't seem in keeping with the point here.

McCafe Coffee
Much was debated in February when McDonald's debuted its coffee at the tents. Would fashionistas deign to drink a coffee-drink that - gasp! - did not come with the green mermaid logo we know so well? Well, it's free and it is there, so the answer is yes.

It's also pretty good, and the people serving it are kind and friendly. I started the week with a non-fat latte (90 calories, unclear amount of caffeine), and thought it did the trick, though halfway through it occurred to me that drinking a full cup of coffee before getting essentially locked into a crowded room for a show wasn't the best idea.

Muscle Milk
Muscle Milk is the trendy favorite for gym-rats and Spandex babes alike. It's basically a sweet-tasting milkshake minus the bubbles and ice cream, swapped with a shot of protein instead. These boxes of Muscle Milk Light, which come in flavors like chocolate and "strawberries'n'creme," weigh in at 100 calories and 15 grams of protein each. They come with tiny straws, all the better to keep lipstick on your lips while slurping down your drink.

This is not a great drink when served warm. But if you are hungry and thirsty, it will definitely get you through the day (and night) without the sad, post-caffeine, crash.

Diet Coke
Diet Coke is the unofficial drink of the fashion world, safe to swig in all situations, while maintaining high energy and slim figure. With just 1 calorie and 47 milligrams of caffeine in 12-ounce can, this stuff gets the job done. However, the barrel of Cokes we checked out was warm; not so great on a hot early fall day.

It's worth noting that there were some regular Cokes in the barrel too, but we are sure this was for the beefy security guards, as drinking highly caloric regular Coke publicly could mark you as a fashion naif.

For serious health info on hydration, check out the advice from our friends at AOL Health. Hint: Just like in fashion, the simplest, most basic choice is always correct.