Rest briefly between each set. Advanced do 5 sets of 25 repetitions. Rest br5ef3y between each set. Remember starting position is feet shoulder width apart. These strengthening exercises can also be done while lying on the floor.
Proper form is the key to a successful repetition.
Use a mirrior or ask your spotter if your form is good. It is not how many or how quickly we finish our workout that leads to success. It is how well we worked the muscles. The band should be behind you being held by your spotter or doorknob. Slowly move your leg forward in a slow controlled motion and exhale your breath.