Summarize the following:
Although changing your diet is the most important aspect of losing weight, exercise also plays a significant role.  As you are attempting to lose quite a lot of weight in a limited amount of time, you will not be able to reduce your total calorie intake through diet alone (without starving yourself). You will need to use exercise to make up the rest. The actual number of extra calories you'll need to burn each day to for weight loss depends on how many calories you cut from your diet. If you went down to 1,200 from 2,200 calories, you'll have to burn an extra 500 calories. The number of calories you burn from exercise depends on your weight and metabolism. On average, a person can burn 731 calories an hour running a 10-minute mile. Cardio is the best type of exercise for fat loss, as it burns the most calories and helps to get your heart rate up.  To lose 12 pounds in a month, you'll need to be doing 30 minutes to an hour of moderate to intense cardio exercise a day. What counts as "moderate to intense" will vary depending on your current fitness level, but a good rule of thumb is that you should break into a sweat within the first few minutes of exercising and keep sweating for the duration of your workout. Some good cardio activities include walking/jogging/running (depending on your fitness), swimming, rowing and cycling. However, an hour-long dance class or an afternoon playing ultimate Frisbee will also provide a good cardio workout and can be a lot more fun! Interval training is an exercise technique which involves alternating between periods of high-intensity and moderate activity. This allows you to work out harder and burn more calories than you normally would.  For example, alternating between a minute of running at your maximum pace, then doing two minutes of a slower jog is much more effective for burning calories than running at a steady pace for the duration of your workout. You can use interval training in almost any kind of cardio exercise. To read more about interval training, take a look at this article. Strength or weight training is not as effective at burning calories as aerobic exercise, but it is still hugely beneficial.   Strength training helps you to build muscle and raise your metabolism. This allows you to burn more calories naturally, even at rest. Strength training also helps you to tone up and trim down, making you look slimmer, even if your weight remains the same. Strength training exercises like squats, lunges and deadlifts are great total body exercise for both men and women. If you're not familiar with these exercises, it's a good idea to book a session with a personal trainer who can show you how to perform the safely and effectively. Try to include two to three strength training sessions into your weekly workouts. It will give you a break from cardio, while still helping you to lose weight. The later you leave your exercise, the less you'll feel like doing it. It may sound like a great idea to hit the gym straight after work, but in reality you'll feel tired and hungry and going to the gym will be the last thing you feel like doing.  If possible, hit the gym in the morning when you feel fresh and motivated. You'll get your workout over and done with early, and have the benefit of the post-exercise feel-good endorphins buoying you up throughout the day. If you're not a morning person, try doing your workout at lunchtime instead. It will help you to clear your head after a busy morning and leave you feeling re-energized when you go back to work. In addition to your workouts, try to come up with some small adjustments to your everyday routine that will increase your overall activity levels. Some examples include:  Walk up the stairs instead of using the elevator. Park farther away from a store's entrance so you have to walk that extra distance. Cycle to work instead of taking the car. Even these small adjustments can significantly increase the amount of calories you burn per week, as long as you do them consistently.

Summary:
Add exercise or physical activity to your daily routine. Do cardio at least four times a week. Try interval training. Do strength training. Exercise early in the day. Make choices that involve more activity.