Bodybuilders are notoriously terrible at knowing why things work for them. They generally know one version of "what" works but the "why" is often rather made-up

Bodybuilders are notoriously terrible at knowing why things work for them. They generally know one version of "what" works but the "why" is often rather made-up ex post facto. That said, the "bodybuilding meta" regarding Bulking/Cutting has evolved in the past decade. Now it's widely accepted that bulking/cutting cycles are probably merely the most efficient way to grow big and only need to "look good" for shows 1-3 times per year. It's also becoming accepted that "recomposition" (losing fat and gaining muscle) is real, and a very useful practice for bodybuilders who need to look good year-round (fitness models, instagram models, social influencers). The year-round nature of daily/weekly direct engagement with fans has driven significant changes in the bodybuilding community. These days, it's believed that recomposition is a valid strategy if you can afford the "slow and steady" pace. If you need to get as big as possible in a limited number of months, and only need to look perfect for a specific target time window, then "bulking and cutting" allows the fastest size growth in the available time (actors preparing for a specific upcoming role, bodybuilders who are competing in an upcoming show). Note also that for most bodybuilders, the aggressive cutting phase requires a fairly large amount of steroids to minimize dramatic loss of muscle mass.