Obama credits H2O for her biceps

Michelle ObamaMichelle LeVaughn Robinson ObamaMichelle Obama says upcoming memoir shares the 'ordinariness of a very extraordinary story' Colbert: Melania Trump’s jacket was ‘one message she did not steal from Michelle Obama’ Melania Trump puzzles with 'I really don't care' jacket MORE credits water with helping her keep her famed physique, which has drawn acclaim particularly for her biceps.

Speaking to a crowd of high schoolers in Watertown, Wis., the first lady touted the benefits of water during the launch of her campaign to get Americans to “Drink Up.”

She told the crowd that it's because “I exercise, eat right and drink a ton of water” that she stays in shape.

The first lady also told the kids that you “perform better when your bodies are hydrated.”

She led the kids in a toast, saying: “You can choose anything in the world but when you choose water you truly are choosing the best thing for yourself.”

Obama has brought in a celebrity crowd to help her with her message, which is part of her anti-obesity "Let's Move!" campaign. Actress Eva Longoria, a prominent Obama supporter, was on hand to introduce the first lady and encourage people to drink more water.

Obama posted a photo of her and Longoria toasting water bottles with the caption "Today, the First Lady is in Watertown, WI with @EvaLongoria to spread the word — drinking water is you at your best. Drink up! #DrinkH2O."

Jay Leno, David Letterman and Jimmy Fallon will drink water throughout their late-night talk shows on Thursday. Katie Couric and the hosts of the “Today” show, “Good Morning America,” “The View” and “Live with Kelly and Michael” also drank water on their programs.

Obama also posted a video to her official Twitter and Instagram account asking people to drink more water.

Filmed before the Watertown rally, the first lady, holding up a blue water bottle, said: "If you want the easiest, best choice for your health, just drink water. Drink up."