NASM recommends that speed, agility, and quickness (SAQ) training for seniors be safe, low-impact, and fun while still promoting movement efficiency, coordination, and reaction time. The "Red light, green light" drill fits this profile because it uses controlled start-and-stop movements that can be adjusted for speed and range of motion based on ability.
Hurdle stepovers, box drills, and mirror drills involve greater joint stress, faster direction changes, and higher impact, which may not be ideal for all senior clients unless they have advanced fitness levels. Thus, Red light, green light is the most appropriate SAQ drill for this population.