Adding carbs intra-workout (I drink ~1 L of orange juice with added salt every session) was a game changer for me. After years of stagnation, I started gaining strength and muscle again.
Carbs spike insulin, which opposes cortisol, making them anti-catabolic. Orange juice also provides potassium, which supports muscle contraction and glucose uptake, while salt (sodium) further lowers stress hormones and improves carb utilization. Plus, muscles need quick fuel for intense efforts, without carbs and electrolytes, you burn through glycogen and start breaking down muscle to make glucose.