My friend and I had started working with Zumba Gold at the end of June 2015 for 5 days a week, from 20-30 minutes. We enjoy exercising to music which makes it less monotonous. We have also found Jessica Smith videos that we like to follow. We do low impact aerobics. We have lost weight and inches. We didn't have much weight to lose and we have no sagging skin. Now we're at a point that we need to firm up. What do we need to do-the same exercises plus concentration on triceps and also floor exercises concentrating on glutes & thighs, use weights, or do we just continue what we've been doing? We'd really appreciate your input!
"Toned" basically means lower body fat with more musculature.
Strength training (weight lifting) is the most effective way to build muscle. Diet is the most important aspect to reducing body fat (eating less than you're expending), and strength training is going to be more effective than cardio for fat loss.
Specifically to answer your question:
What do we need to do-the same exercises plus concentration on triceps and also floor exercises concentrating on glutes & thighs, use weights, or do we just continue what we've been doing?
A good strength training program is going to get the job done a lot faster, and provide numerous other medically documented benefits. Low impact cardio is great, but it doesn't increase bone density like higher impact training or strength training does.
From a 1999 study:
Over the past 10 years, nearly two dozen cross-sectional and longitudinal studies have shown a direct and positive relationship between the effects of resistance training and bone density. ... High-intensity resistance training, in contrast to traditional pharmacological and nutritional approaches for improving bone health in older adults, has the added benefit of influencing multiple risk factors for osteoporosis including improved strength and balance and increased muscle mass.
Coupled with a good diet (eating less than you're using), if you enjoy Zumba and other low impact aerobics, you can get "toned". But it will take longer and not yield the same results as strength training.
I would recommend:
Dial your diet in. Use something like myfitnesspal.com to track every calorie for a week or two, just to understand how much you're putting into your body. Likewise, use a calorie estimator to determine how much you should eat of what. This gives you good concrete information on how to eat, what's too much, and what's not enough.
Buy Starting Strength, follow the A/B workouts near the back of the book. Try to do 2 or 3 workouts a week.
Keep doing your Zumba and whatever other aerobic activity you enjoy.
That would be a pretty ideal situation. You'll have doctors and exercise folks high fiving you on your plan, and you'll fast track all of your goals. Plus, you'll be making some big swings towards long term health. A plan like that will have positive impacts going decades into your future.