The phrase "untrained subjects" refers to people who haven't received any specific training or instruction in a particular area or skill. Full definition
Strength training in trained or untrained subjects likely does not lead to a shift in type I to type II muscle fiber proportion. (strengthandconditioningresearch.com)
Strength training in untrained subjects causes a shift in muscle fiber proportion from type IIX to type IIA muscle fiber type, and may also produce similar effects in trained individuals. (strengthandconditioningresearch.com)
In terms of chronic adaptations, greater strength increases were evident by untrained subjects for the first exercise of a given sequence, while strength increases were inhibited for the last exercise of a given sequence. (lift-heavy.com)