Speed Improvement Focus: EARLY SPECIALIZATION Vs. MULTILATERAL DEVELOPMENT FOR YOUNG ATHLETES March 10, 2021November 4, 2010 by NASE Inc. Most experts feel that it is best to avoid specialization prior to age 15 or so, depending upon the stage of growth and development. Others argue for specialization as early as possible whenever the child is ready. For access to this article, you must be a current NASE member. Please log in to your account or purchase your NASE membership.