Preheat the grill to medium-high heat, about 400°F.,

Season 6 ounces of chicken breast with salt, pepper, and a teaspoon of olive oil.,

Grill the chicken for 6-7 minutes per side until internal temperature reaches 165°F and juices run clear.,

While the chicken is grilling, prepare the vegetables: chop 1 cup of broccoli florets, 1/2 cup of bell pepper strips, and 1/2 cup of zucchini slices.,

Heat a non-stick skillet over medium heat and add 1 teaspoon of olive oil.,

Sauté the vegetables for 5-6 minutes until tender but still crisp. Season with a pinch of salt and pepper.,

Prepare the avocado dressing: mash 1/2 of a ripe avocado and mix with 1 tablespoon of lemon juice and 1 teaspoon of water until smooth.,

Once the chicken is cooked, let it rest for 5 minutes, then slice into strips.,

Assemble the bowl with grilled chicken, sautéed vegetables, and a dollop of avocado dressing on top.,

Garnish with 1 tablespoon of chopped fresh parsley or cilantro for added flavor.,

Serve immediately and enjoy a high-protein, low-carb meal perfect for marathon training.