Quadriceps (front of thighs)
(A) Stand tall and hold the back of a chair with one hand to help maintain balance, if necessary, then lift one knee to hip level. Keep abs pulled in toward spine and back straight. (B) Contract the front of the thigh as you slowly straighten the knee, extending the leg out to the front with toe pointed. Try to keep lifted leg at hip level throughout the move. Bend knee, bringing leg back to bent-knee lifted position. Do not lower foot to the ground until you've completed all reps; switch legs to equal one set.
Challenge yourself: Point and flex the foot six to 10 times at the top of each rep to further target the front of your thighs.