In order to lose 15 pounds in a month, you'll need to follow a vigorous fitness routine and engage in physical activity each day. It's important to continue switching up your work outs in order to shock and stimulate your muscles and metabolism, and to keep from reaching a fitness and weight loss plateau. Here is what a typical week of fitness should look like in order to lose this type of weight:

Day 1

Start your week off with a metabolism boost, and engage in a form of intense cardio for an hour. During this exercise session, your heart rate should be elevated, your breath should be short, and your sweat glands should be activated. Choose any type of cardio you'd like, whether it be jogging, swimming, biking, hiking or using a fitness machine. Follow up your cardio session with at least 15 minutes of abdominal exercises.

Day 2

On day 2, you should focus on strength training, and spend an hour lifting weights and performing other strengthening exercises, such as squats, lunges and planks. It would be ideal to take an hour long weight lifting class or spend this time with a personal training if you're just starting out. After your weight lifting session, hop on a fitness machine for 30 minutes. This can be a bike, Stairmaster, elliptical trainer or treadmill, as long as it's a different activity than you performed the previous day.

Day 3

Treat your muscles right on this third day with either a Pilates or yoga class, to stretch them out after all that strength training and keep them looking great. These flexibility classes will tone, lengthen and strengthen your muscles, while burning calories, and are important to include in your fitness routine. On the third day, also get outside to enjoy an hour of moderate activity. Maybe you can speed walk through your favorite trail or take a bike ride along the coast.

Day 4

On day 4, participate in a vigorous fitness class that lasts at least an hour and simultaneously incorporates both cardio and strength training. Try a boot camp class, a circuit training class, or anything else that constantly switches up the exercises. This will enable you to burn more calories in less time and keep your metabolism revved throughout the day.

Day 5

Try another challenging class on day 5, but this once should solely focus on cardio. Perhaps you can participate in a spinning class or cardio kickboxing. Follow this up with 15-30 minutes of abdominal work and possibly some yoga or Pilates.

Day 6

On day 6, spend an hour and a half in the gym. Pick a cardio machine to stay on for 45-60 minutes, and hit the weight room for 30-45 minutes.

Day 7

Take day 7 to relax and give your muscles a break; you deserve it! Don't be completely idle, however, and consider a light walk or some low-intensity yoga.

To lose 15 pounds in a month, you must continuously keep moving. Couple your workout routine with a healthy diet, and ensure you're consuming the right amount of calories to fuel your workouts.