[header] How to strengthen quads using a fitness ball [title] Practice all leg moves over a padded mat. [step] Because it takes time to get comfortable balancing on the fitness ball, practice each move on an exercise mat to cushion your fall and help your wrists support your weight more comfortably. [title] Engage your core muscles with each exercise. 
[step] By tightening your abs and back as you work your quads, you can help stabilize yourself and tone your core as you work out. [title] Perform traditional squat moves for the quadriceps.