Eli Manning, quarterback for the New York Giants and younger brother to Peyton Manning, who will compete in this Sunday's Super Bowl, may be using the off-season for some downtime but his dog is getting a mega workout.

In addition to being a celebrity spokesman for Dunkin Donuts, Manning, 33, has an endorsement deal pitching Purina Pro Plan, a "sports line" of dog products, which include wet and dry foods, snacks and supplement bars. Yes, these are energy bars for dogs.

(Credit: Nestle Purina)

Dogs are fed the Purina ReFUEL Bars within 30 minutes post-exercise, helping "replenish muscle energy stores and promotes muscle rebuilding after activity," Purina says. The bars retail for $2.99 a piece or you can buy a 12-bar multipack at pet specialty stores. The amount of a bar that should be fed to a dog depends on its weight.

Read and Watch: The Best and Worst Super Bowl Ad Teasers

On Wednesday, the self-described "lifelong dog owner" hosted the "Purina Pro Plan MANning vs. DOG Challenge in New York City." At the event, athletes competed against dogs in physical challenges that included flying disc, weave pole and speed races.

(Credit: Amy Sussman/AP Images for Nestle' Purina PetCare)

Manning's 4-year-old Cavalier King Charles Spaniel, Chester, was not present at the promotional event. Instead, Rampage, a dog owned by one of Purina's trainers, competed with Manning.

In Photos: The Coolest Super Bowl Ticket Designs Through the Years