Many fitness experts maintain that exercisers must work within the 8 to
12 repetition range to initiate muscle hypertrophy. However, recent studies suggests that low-load,
high-volume strength training can also impact muscle growth.Researchers from McMaster University in Hamilton, Ontario, studied 15 men as they performed four sets of unilateral leg extensions at 90% 1-RM and 30% 1-RM. The subjects were instructed to work until failure. The study authors reported that at 90% 1-RM, subjects usually managed 5–10 repetitions before failure; at 30% 1-RM, failure set in at about 24 repetitions.