One of the most underrated factors for gym performance and recovery is simply eating enough.
Too many people undereat, then wonder why their strength, energy, and progress stall. If you want to perform well in the gym, your body needs enough fuel—especially carbohydrates, including simple sugars, which are often unfairly demonized. Your muscles rely on glycogen as a primary fuel source for high-intensity training, and without adequate glycogen stores, performance can suffer.
Recovery is just as important. After training, make sure you're getting enough calories and nutrient-dense foods, with an emphasis on animal-based foods. Plant foods don't provide the same nutritional value. Glycogen also needs to be replenished after training, so consuming enough carbohydrates remains important.
That said, everyone should consider their own metabolic health. If you're increasing your sugar intake, do it gradually and pay attention to how your body responds.