Hi Pam,   Absolutely!  Once you are about 20 minutes into a workout, your body switches from using carbohydrates (like the sugar in your blood stream) to stored body fat for energy to do the workout.    For the best results, make sure you are working hard enough.  I like to use the "talk test" as a quick way to check how I'm doing.  Here it is (example I use is walking):   If you can walk and talk with no trouble, pick up the pace. If you can talk, but need to take a breath every 4-5 words, you're right on track. If you are gasping for breath after every word, slow down!   Setting aside time for a workout can be hard, so be sure to make the most of your time by working out hard enough to see results.   Also, a 1 hour exercise video once a week, will not give you the results you want either.  You need to do it regularly, work your way up to 5 times a week.   All the best,   Lisa Nelson, RD, LN Lose Weight