The first step in losing the most weight in the shortest time possible is to make a commitment to the process. Once you've done that, your biggest allies are diet changes and exercise. It's possible to lose weight with just diet changes or just exercise, but the most successful efforts involve both. You should set aside one hour every day for some type of physical activity, although there is no need to do a vigorous workout every day. To ensure a day of rest each week, you should include at least one day on which you do only the mildest forms of exercise, such as walking.
Work out with time and intensity in mind. Yes, longer workouts are going to help you burn more calories, but more intense sessions burn more calories per minute, thereby making better use of your time. Plan to do steady-state cardiovascular exercise, such as running, walking, cycling, swimming or any other aerobic activity that you like, for 30 to 60 minutes three or four days a week. Push yourself a little beyond your comfort zone by increasing your speed, adding incline or resistance to your exercise machine or adding a few minutes to your planned workout time.
Perform a high-intensity interval workout two days a week. Run, swim or cycle, but after your warm-up, speed up to about 80 percent to 90 percent of your maximum speed for one minute, then slow down to about 50 percent of maximum for another minute. Alternate between the two for a total of eight rounds. This type of work greatly improves your aerobic and anaerobic fitness and boosts your metabolism for the rest of the day.
Work strength training into your routine two days a week, targeting all major muscle groups -- including the legs, arms, back, shoulders and abdomen. Compound exercises, which work more than one muscle at a time, will help you gain muscle in less time. Try squats and lunges for the buttocks and legs. For the upper body, try bench presses for the chest, arms and shoulders and pull-ups and push-ups for the back, arms and chest. For the abdominals, try planks, which also work the shoulders and legs.
Track your calories religiously. If you have a smartphone, download a weight loss app that allows you to enter your weight and age and weight loss goals. Next, enter the foods you've eaten and the exercise you've done and let the app calculate your net calories for the day. If you don't have a smartphone, use an online "caloric needs" calculator to determine how many calories you need to consume to meet your goal. Write down everything you eat each day, then use an online "calories in foods" calculator to figure out how many calories you've consumed. To lose 1 pound of fat, you must create a deficit of 3,500 calories, meaning you're burning 3,500 more than you've consumed.
Use your calorie app or calorie estimations to make changes to your diet. As you track your calories, you'll find that vegetables and fruits are low in calories, so you'll be able to eat more of them. Stock the fridge with easy-to-access foods, such as apples, bananas or carrot sticks, so you can snack on them when you get hungry. Cut out late-night snacks and high-sugar and high-fat foods as much as you can.
Drink plenty of water. Being dehydrated can make you feel sluggish and keep you from staying motivated to complete your exercise routine. The American Council on Exercise recommends at least 17 to 20 ounces two to three hours before you work out and 8 ounces 20 to 30 minutes before your workout.