Training muscles while they are fully stretched is probably the best way to build muscle size for experienced lifters. Adding exercises that only work the muscle in a shortened position doesn't seem to help you grow more muscle compared to just focusing on the stretched position.

Our current analysis shows that the evidence we have reviewed leans toward prioritizing the stretched position of a muscle during resistance training for muscle growth, also known as hypertrophy. What we have found so far suggests that training a muscle while it is fully lengthened may be the most effective approach for experienced lifters. We analyzed the available research and found that 54.0 studies support, 0 studies refute [1]. The evidence we have reviewed suggests that focusing on the stretched position might be the best way to build muscle size. Adding exercises that only target the muscle in a shortened, contracted state does not appear to provide extra growth benefits compared to focusing on the stretch. Our analysis of the available research points to a clear pattern, though we recognize this is a partial view that will improve as more data becomes available. We do not claim this is a final answer, but rather what we have found up to this point. The evidence we have reviewed leans toward keeping the stretch as a primary focus when designing your workout routine. If you are looking to build muscle, you might consider choosing movements that naturally place the target muscle in a lengthened position at the bottom of each rep. This approach aligns with what our current analysis shows, and it offers a simple way to structure your training without overcomplicating your routine.