Congratulations on losing a significant amount of weight! The next step is to tighten loose skin left on your body especially around your legs, so you'll feel comfortable wearing shorts and be ready for swimsuit season. Since your legs are a larger muscle group, toning them will take some work. Start by using light dumbbell weights (or no weight) and add weight as needed; the trick is to start slow. Below are some exercises that will help you tighten loose skin and tone up your legs in no time! Try to do 10 - 15 repetitions of each exercise and repeat for 2 - 3 sets.
Squats will help tighten both your legs and your butt. You can perform this exercise with or without dumbbell weights (you may want to try it first without weights). Stand with your feet slightly wider than shoulder width apart. Bend your knees and slowly lower your body until your thighs are about parallel with the floor; then stand up again and repeat.
2. Front Lunges
To begin this exercise, stand up with your feet slightly less than shoulder width apart. Take a giant step forward with your right leg, lowering your body until your left knee almost touches the floor. Push your body back up to your standing position using your right leg. Repeat the exercise with your left leg and continue alternating legs until you reach your desired amount of repetitions or until you start to fatigue.
3. Alternating Squat Kicks
Squat kicks are similar to regular squats; start in a standing position with your feet slightly wider than shoulder width apart. Squat down until your thighs are about parallel with the floor; then push up with your left leg while your right leg simultaneously kicks out to the side. At the height of your kick, your leg should be straight and parallel with the floor. Lower your body back down to your squatting position (thighs about parallel with the floor); then push up with your right leg while your left leg kicks out to the side. Continue alternating kicking and squatting legs.
4. Reverse Plank Dips
This exercise will help you tone up the back of your legs (hamstrings). To begin, sit on the floor with your legs straight and extended out in front of you. Your arms should be behind you with your palms facing the floor. Raise your body up until your arms are fully extended (straight) and your torso and legs form a straight line. This is your reverse plank position. Keeping your legs straight, slowly dip your body down until your butt almost touches the floor; lift your body back up to the reverse plank position (using your hamstrings) and repeat.
5. Side Lunges
To perform this exercise, stand up with your feet about shoulder width apart. Keeping your left leg planted, lunge laterally (out to the side) with your right leg until your right thigh is almost parallel with the floor. Push with your right leg back up to standing position and repeat with your left leg by lunging to the left; continuing alternating lunging legs.