Most trainees overtrain ...train too often, too many sets and don't carefully track their progress/gains objectively. Having said that, many of these studies use newbies as research subjects. Most of the gains in "strength" a raw recruit will experience is due to SKILL not actual strength improvement. Even a barbell curl, a uni axial movement where you'd think no skill is involved ...nope. I'll guarantee every trainee learns to "game" it. They want to get stronger and will find ways to make the exercise more efficient...ie skillful. After 3 or weeks of break in training, where everyone learns most of the "game" in the movement that's where the measurements should start...in research subjects and personal trainees. That's where the real strength progress is a reliable measure.
Every exercise has two components: Skill and strength.
Every exercise has two components: Skill and strength.