Different repetition ranges in resistance training produce specific adaptations: low repetitions (3-5 repetitions) maximize strength gains, high repetitions (20-28 repetitions) maximize endurance and aerobic capacity, while intermediate repetitions (3-11 repetitions) maximize muscle hypertrophy.

Study: Divergent Strength Gains but Similar Hypertrophy After Low-Load and High-Load Resistance Exercise Training in Trained Individuals: Many Roads Lead to Rome.

This study found that lifting light weights for many reps and heavy weights for few reps both made people stronger and their muscles bigger — even though the claim says only heavy weights make you strong and medium weights make you big. So the study contradicts that idea.

Study: The impact of repetition mechanics on the adaptations resulting from strength-, hypertrophy- and cluster-type resistance training

The study looked at lifting weights with different rep counts but didn't test the high reps (20-28) for endurance like the claim says, and it found that lower reps were better for strength than the hypertrophy rep range, which partly goes against the claim.

Study: Muscle hypertrophy and strength gains after resistance training with different volume matched loads: a systematic review and meta-analysis.

The study shows that lifting heavy weights makes you stronger, but muscle growth is similar no matter how heavy you lift if the total work is the same. It doesn't test endurance at all, so the claim is only partly right and goes too far.

Study: Loading Recommendations for Muscle Strength, Hypertrophy, and Local Endurance: A Re-Examination of the Repetition Continuum

The study says that doing different numbers of reps in weight training doesn't always lead to just one specific result like more strength or endurance, which goes against the claim that each rep range has a special benefit.