Are squats really the only leg exercise you need? New research compares squats directly against leg extensions, revealing that each exercise targets different parts of the quadriceps.
Your quadriceps are four separate muscles that require thoughtful training to grow. Research points to full range of motion, a mix of compound and isolation exercises, adequate weekly volume, and progressive overload as the key drivers of quad hypertrophy.
Two recent studies examined whether training muscles in a stretched position produces more growth. For the hamstrings, the answer was a clear yes. For the biceps, the two positions produced nearly identical results. The difference may come down to how much each muscle's working length actually changes.
A 2024 study found that taking a full week off from training in the middle of a 9-week program didn't help or hurt muscle growth in trained young adults. However, continuous training produced better strength gains than including a deload week.