Spray a large non-stick skillet with cooking spray and heat over medium heat.
Add the crumbled lean turkey sausage to the skillet and cook until browned and cooked through, about 5 minutes. Remove sausage from skillet and set aside.
In the same skillet, add diced onion, red bell pepper, and green bell pepper. Sauté for 3-4 minutes until vegetables are softened.
Add chopped spinach to the skillet and cook for 1-2 minutes until wilted.
In a bowl, whisk together the egg whites, salt, black pepper, ground cumin, and chili powder.
Pour the egg white mixture into the skillet with the vegetables and cook, stirring gently, until eggs are fully cooked, about 3-4 minutes.
Return the cooked turkey sausage to the skillet and stir to combine with the eggs and vegetables.
Remove the skillet from heat and sprinkle the reduced-fat shredded cheddar cheese evenly over the mixture. Allow cheese to melt slightly.
Warm the whole wheat tortillas briefly in a microwave or on a dry skillet to make them pliable.
Divide the egg, sausage, vegetable, and cheese mixture evenly among the 6 tortillas, placing the filling in the center of each.
Fold in the sides of each tortilla and then roll tightly to form burritos.
Wrap each burrito individually in plastic wrap or aluminum foil and place in a freezer-safe container or bag.
To reheat, remove wrapping and microwave the frozen burrito on high for 2-3 minutes or until heated through. Alternatively, thaw overnight in the refrigerator and reheat in a skillet or microwave.