Legs are the heavy lifters when it comes to staying active. “As you age, leg strength becomes even more vital, since your legs are essential for routine movements like going up and down stairs, sitting and rising from chairs, bending over, and standing up,” says Mara Smith, a certified athletic trainer and strength and conditioning specialist with Harvard-affiliated Mass General Brigham Sports Medicine. “If your legs are weak, your life can literally come to a standstill.” Strong legs also help