In addition to lift or body part specificity in fiber type, different individuals have varied fiber type averages. If we take all of the muscles of the human skeletal muscle system, one individual may be 60% faster twitch and 40% slower twitch, while another might have the opposite ratio. Those individuals with faster fibers will tend to be able to generate and hold onto more fatigue, while those with slower fiber types have a gigantic work capacity and recovery ability, so will be able to dissipate fatigue rapidly as well as have very high MRVs. Though in a bit of irony, those same slower twitch individuals tend to experience less success in their results because of the poor adaptive nature of their dominant fibers to heavy resistance training.
Fast-twitch-dominant individuals (those with a lot of fast-twitch muscle fibers) are genetically predisposed to better powerlifting performance. But, the faster twitch you are, the more homeostatic damage your training exerts, and the slower you recover. Here’s another fact: those with smaller muscles and less strength can recover better from many kinds of training because they literally don’t have the strength to cause as much damage and don’t have the same muscle size to have to fix. Less damage, less fixing, and viola; higher weekly volumes. A marathon runner may be able to train with the same volume as a very good powerlifter, and perhaps even more. Does that mean they are better at powerlifting? Absolutely not. It just means they are crappy at stimulating and amazing at recovering.
Lifters with larger muscles and connective tissues tend to be able to do more homeostatic damage during training, and thus require concomitantly longer to taper. Muscle soreness in larger muscles almost always lasts longer and is more profound than soreness in smaller muscles. Lifters who are prone to add size to high extents also tend to be more fast twitch in muscle composition. Faster twitch muscles usually have longer recovery curves than slower twitch muscles, mostly because they can generate more force and take more damage, but also because they are not as well vascularized as slower twitch fibers and thus don’t receive nourishing bloodflow as quickly to match slower twitch healing rates.
The top lifters tend to be more predominantly fast-twitch. This means among other things that they likely benefit from slightly lower repetition ranges and total volumes, especially in hypertrophy phases. Yes, that elite powerlifter may grow almost maximal muscle size from sets of 5, but you will likely benefit most from 6 - 10 reps per set.
