“When you work out, you’re physically breaking down your body: the muscle fibers, your immune system, your connective tissues, everything. If you don’t recover, you’re just breaking your body down over and over again,” says Karli Alvino CPT, FNS, coach at Mile High Run Club. “No matter how you’re exercising, nutrition, hydration, and sleep are the main pillars of recovery,” says Alvino. That means eating ample protein and high-quality carbohydrates, consuming (at least) half your body weight in ounces of water, and aiming to get 8+ hours of sleep a night, she adds.