### Instruction: Jill, a 60-year-old personal training client, wants to improve her hip flexibility. Identify two exercises commonly done in a Pilates class that would address core strength and flexibility, thus improving Jill's lower back health.
### Response: One exercise is the criss-cross, which helps target the participant’s core strength and flexibility. The participant alternates bringing one shoulder towards the opposing knee, while keeping their hands on the back of their head, lying face-up, and curling their head up. Another exercise would be plank leg lift, which starts as a regular high plank. The participant alternates lifting one leg off the floor, keeping their core engaged to stabilize the movement.