A safe rate for weight loss is about 1 to 2 pounds per week. So you could lose between 4 and 8 pounds by the end of a four-week training program. Losing more and keeping off what you've already lost will take more time. In fact, it will take a lifetime. So find an exercise or activity you don't mind doing several days per week. If you aren't already getting at least 30 minutes of moderate activity, which includes house or yard work as well as cardio like walking or using cardio machines at a moderate pace, you may need to build to this four-week training plan by adding 10 minutes to your cardio every two or three sessions.
Step Up Your Cardio
Assuming you are already getting 30 minutes of moderate cardio five days per week, to lose weight you will need to burn additional calories by either working longer or working harder. Of the two, working harder, or increasing the intensity of your cardio workout, is more efficient, because the more intense your workout, the longer you will burn calories post-workout. During your first week, alternate three-minute intervals of about 60 to 70 percent of your maximum heart rate with two minutes at 75 to 80 percent. Each week for the following three weeks, reduce your moderate cardio intervals until you are doing 30 minutes at 80 percent. As a rule of thumb, assume your max heart rate to be 220 minus your age.
Without strength training, your weight loss plan will cause you to lose muscle as well as fat. Stronger muscle will also make it easier to perform your intense cardio. Start with the big muscle groups. At least two non-consecutive days per week, grab a pair of dumbbells and lie supine on a flat bench for dumbbell bench presses for your pecs. Then do seated shoulder presses for your side and front delts, rear delt rows on a bench with your elbows out for your posterior delts and upper back and stay in the same position with your elbows tucked in to work your lats. Follow this with biceps curls and triceps extensions. In week one, choose a weight where eight repetitions are a struggle, but you can do them in proper form. Do two to three sets, depending on what you can handle, and build over the next four weeks to doing sets of 12 reps.
On at least two non-consecutive days work the muscles of your lower body. Again, start with the larger muscles doing two to three sets of eight squats. If free squats are too difficult, hold onto a support or do stability ball squats. If free squats are easy, hold dumbbells at your sides. Work up to sets of 12. Then lie on your side for lying hip abductions and adductions -- for your inner and outer thigh -- holding a dumbbell against your leg for resistance. Choose a weight with which eight reps is a struggle in proper form. Do two to three sets, building to 12 reps by the end of your four weeks.
As your core provides stability for all your other work, save it for last so you won't tire out. Unlike your other muscles, you can work your core on as many as five consecutive days. In week one, start with 25 crunches and 25 twist crunches on each side and add five each week. If standard crunches are too easy, try doing them on a stability ball. Hold front, back and side planks as long as you can, building to 60 seconds by the end of your four weeks.
Week Five and Beyond
In week five and beyond, continue increasing the intensity of your cardio. Most healthy individuals can go as high as 90 percent of maximum heart rate, and higher for two-minute intervals alternating with three minutes of moderate work, but check with your physician first. After four weeks, and every four to six weeks thereafter, it will be time to change the exercises you do for each muscle group. Once you can hold planks for 60 seconds, try pikes and side dips and balancing on a stability ball. Of course, weight loss will also require reduced calorie intake, so maintain your good eating habits.