Yoga asana incorporates a lot of body weight exercise, so yes you’ll gain a lot of strength in a practice like Ashtanga or Iyengar. A lot of asanas that don’t l

Yoga asana incorporates a lot of body weight exercise, so yes you’ll gain a lot of strength in a practice like Ashtanga or Iyengar. A lot of asanas that don’t look complicated require very subtle muscle development, but you certainly can’t do Astavakrasana or press up into Pincha Mayurasana without tons of strength. For lower back I’ve found practicing Salabhasana, Dhanurasana, or Urdva Dhanurasana have helped.