Beginner: Bent-Knee Extension
Targets: Hamstrings (back of thigh)
- Lie faceup on floor with arms at sides, knees bent 90 degrees and heels shoulder-width apart on a stability ball.
- Lift hips toward the ceiling, being careful not to overarch back.
- Hold for 3 counts and lower.
- Repeat for 8 to 10 reps.
Beginner: Scissor Kick
Targets: Adductors (inner thigh)
- Lie faceup on floor with arms at sides, palms down and legs extended.
- Lift legs about 45 degrees, pointing toes.
- Quickly open and close your legs, crossing the right thigh over the left and then reversing the movement.
- Continue scissoring legs; do 12 to 15 reps per side.
Intermediate: Extended Leg Curl
Targets: Hamstrings (back of thigh)
- Lie faceup on floor with heels placed shoulder-width apart on a stability ball, arms at sides on floor, palms down.
- Lift hips toward ceiling and hold for 2 counts.
- Slowly pull ball toward body, keeping hips lifted, then roll it back toward start.
- Do 8 to 10 reps.
Intermediate: Ballerina Squat with Knee Bend
Targets: Adductors (inner thigh)
- Stand with feet wider than shoulder-width apart, toes pointed out. Bend knees 45 degrees and hold.
- From here, shift your body weight to the left side, keeping left knee bent while straightening right leg.
- Hold for 1 count; switch sides, straightening left leg and bending right knee.
- Repeat; alternate legs for 8 to 10 reps per side.
Advanced: Single-Leg Hip Curl
Targets: Hamstrings (back of thigh)
- Lie faceup on floor, legs extended, arms at sides and heels shoulder-width apart on astability ball.
- Raise hips toward ceiling and hold.
- Lift your right leg off the ball, pointing toes toward ceiling.
- Slowly pull the ball toward your body using your left leg; keep hips lifted.
- Roll back to start and repeat; do 8 to 10 reps per leg.
Advanced: Single-Leg Knee Adduction
Targets: Adductors (inner thighs)
- Standing with feet shoulder-width apart, lift right leg off the floor, bending right knee 90 degrees; keep hands on hips.
- Bring right leg 45 degrees away from body, balancing on left leg.
- From this position, bring right knee toward right side and back toward center.
- Do 8 to 10 reps; return to start and repeat on opposite side.
Source Thanks to http://www.fitnessmagazine.com/workout/thighs/exercises/sleeker-thighs-in-3-moves