In healthy older adults around 71 years old, doing resistance training for 12 weeks leads to measurable increases in thigh muscle size and leg strength, whether or not they previously did aerobic exercise.

Gentle weight training done slowly and steadily twice a week for 12 weeks can make older adults' thigh muscles thicker and stronger.

Older adults, even those over 85, can gain just as much leg strength as younger seniors from 12 weeks of regular weight training — and some even gain a bit more!

Whether you use light or heavy weights, your muscles can grow about the same amount if you train hard enough—both methods work for building muscle size.

If older guys who are already active do full-body strength training three times a week for three months, they’ll get stronger legs and bigger leg muscles—even without adding extra protein to their diet.

If female college athletes who already lift weights add a specific workout plan and eat 24 grams of protein before and after each session, they’ll get way stronger in their legs—adding about 90 kg to their leg press max in just eight weeks.