Guess what??? NO ONE has time to work out, however; those who are serious MAKE time to workout. You can't just expect time to fall in your lap that is labeled "workout time". That just doesn't happen, we have things come up, emergencies, priorities, events, etc. You HAVE to schedule your workouts just like you would a meeting or a family dinner/party and such. Once you have carved out a window for that specific activity, you have made time to workout. Now, I know a lot of us barely have time to breathe some days, so if you want insane results in a short amount of time, you better be willing to put in your FULL (110%) effort into your workout. HIITs are a very effective way to train. a HIIT stands for High Intensity Interval Training. Interval workouts is where you do bursts of high intense movement or activity at maximum effort for about 30-60 seconds and rest for the same amount of time. HIIT's can be anywhere from 15-30 min long. I'd keep the max at 30, I feel anything longer than that could produce injury or break down the body a little too much (only if you are truly giving your full effort). You can create a HIIT workout in ANY exercise activity. You just have to add 30-60 seconds of INTENSE (maxium effort) intervals and alternate between your highest intensity and rest. There are scientific studies that show HIIT workouts can be more effective than regular, steady cardio exercise. HIITs actually elevate your metabolic rate and create a longer after burn effect. This means that you are burning more calories at rest AFTER your workout, where as traditional cardio you'd be burning more calories during only the workout and then it is steady throughout the day. I usually do HIITs in my runs or just do a fun dvd workout that has HIITs in it. NOW DON'T get me wrong, traditional cardio is still a good form of exercise and HIITs may not be for everyone, but they do produce some insane results. DISCLAIMER: Make sure you consult a physician before you start doing any different type of exercise, they are the ones able to tell you what would work best for your body by examining specific characteristics or health issues that you are having or may have.