Some research studies use weekend warriors as subjects. They usually call them recreationally active. Other studies use subjects with significant weight room experience. They are typically referred to as trained.
A study published in the Journal of Strength and Conditioning Research measured the validity of a classic fatigue test from the 1970s that used recreationally active men. It found that fast-twitch muscle fibers used for short bursts of strength, like sprinting and weight lifting, were associated with quicker quadriceps fatigue.
In a reexamination of this finding, 15 trained men in their early 20s performed maximum knee extensions to calculate peak torque and quadriceps fatigue after 30 and 50 reps. Peak torque in the trained men was 46% greater than the recreationally active subjects. Quad fatigue ranged from 53% to 72% with no relationship between muscle fiber type.