Exercise is the best thing for your health regardless of your size or special medical considerations. The causes of obesity are multifaceted, but one thing we do know is that exercise can be a very effective treatment.

There is substantial evidence that obesity is caused by a lack of physical inactivity, versus simply overeating. Adding activity, such as a group fitness class, to your lifestyle will stimulate your metabolic rate, increase your energy and significantly reduce your risk of diseases that are associated with being overweight.

Exercise, whether alone or in combination with a sensible diet, produces the best long-term weight loss results. Even with keeping your food intake constant, burning 300-400 calories per exercise session three times a week could result in a 16-pound weight loss in one year.

With moderate caloric restriction, the weight loss can be even greater. Regular exercise can also help control appetite and improve psychological outlook, along with many other health benefits.

Those considered "plus size" can follow the guidelines below to successfully begin and/or participate in a group exercise program:

• Have a check up. Before beginning any exercise program, schedule a complete medical exam and diagnostic exercise test with your personal physician. If you are overweight and have been inactive, you have two major health risk factors and will need a physician's clearance prior to joining a class. Visiting your doctor will also give you a good base line of your current health, which you will be able to use as a point of comparison for your health improvements upon starting your fitness program. In addition, it will ensure the most benefit with the least amount of risk.
• Discuss expectations. Prior to engaging in physical activity, you should discuss your previous exercise experiences, what types of activities you enjoy, time constraints, equipment and clothing needs, any personal concerns as well as clearly defining your goals in beginning an exercise class. This can be done with your doctor or fitness instructor. Many individuals have greatly benefited from keeping a journal of the progress, feelings and goals. Set up your personal plan for success.
• Take a multi-disciplinary approach. Involve several health professionals including fitness instructors, doctors, psychologists, nutritionists and physical therapists, as well as family and friends in your pursuit to make physical activity a life-long habit. Enlisting the support of others and making them aware of your goals will help you stay on track and will keep you from being unknowingly sabotaged.
• Find the right instructor. Seek an instructor who is certified, a role model, motivator and lifestyle educator. He/she should be experienced in working with "plus-size" individuals. You can search for such instructors at the American Council On Exercise's web site (www.ACEFitness.org), by checking with your local health clubs, or finding one by word of mouth. Taking the time to research and interview an instructor that's suitable for your needs can absolutely make the difference in your sticking to the class and getting results, or dropping out and, even worse, getting injured.
• Find a beginner class. You first need to choose a class to match your ability level. Find out when new groups are beginning or if new students can be integrated into an existing class. The intensity of the class should be low initially, with your objective being that you are able to exercise as long as possible with the least amount of discomfort. The longer the duration, the greater the caloric expenditure. The environment should be supportive, non-competitive and make you comfortable.
• Choose class formats. The options are virtually unlimited. As a beginner you should strive for low or non-impact classes. But the music, environment and class formats can vary extensively. You may prefer traditional aerobics which can be done to any style of music, or you may want to try a step class to add dimension to your workout. Other formats include studio cycling, muscle toning, Pilates, yoga, fit ball, ballet, body pump, kick boxing, belly dancing, Tai Chi, country line dancing, boot camp, seniors classes, chair dancing, Irish steps and more.
  Being "plus-size" does not negate your ability to join any one of these formats! If you prefer using a video in the privacy of your home rather than attending a class, the largest selection of exercise videos can be found online at www.collagevideo.com. Many fitness facilities will allow you a trial period prior to making an investment, so take advantage of many different formats and you just may find one that you love.
• Listen to your body. You should learn how to monitor your heart rate and be aware of other signs and symptoms of overexertion like joint pain, excessive fatigue and a flushed complexion. Your body will give you warning signs if you are over exerting yourself. You should to sweat and breathe heavily in the beginning until your body becomes acclimated, but never, ever exercise to the point of pain.
• Attire. Start out with a new pair of sneakers that are supportive and properly fitted to your foot. Injuries can begin from the feet and work their way up your body. Your shoes may wear out faster, so replace them more often. There is a greater selection of exercise apparel available for larger exercisers. Choose fabrics that breathe and will absorb sweat. Dress appropriately for the environment. Dressing too warm can lead to heat illnesses and will force you to decrease your needed intensity.
• The exercise prescription. You should strive for 30 minutes of activity at low intensities most days of the week. You can start out with three sessions weekly and, ideally, work up to seven days a week at a low intensity. Gradually increase your intensity before you begin to increase the duration of your sessions. The rate of progression should be slow. Breathe naturally and be sure to warm up and cool down with each session. Initially, you can break your sessions up into shorter segments until you build endurance to complete a class.
• Precautions. Pace yourself and watch for signs of over exhaustion. Avoid high-impact activities. Avoid any jarring or twisting motions that may result in slipping or twisting the knees and ankles. Ask for modification options if you do not have the strength or endurance to perform a particular movement.
• Set up rewards. Have a positive feedback plan to reward yourself for reaching milestones throughout your program. For example, when you've exercised for one month, treat yourself to a new aerobic video. When you've built up to exercising five days a week, indulge in a new pair of sneakers to add a bounce to your step. When you sign up for a new season of classes, invest in a heart rate monitor. This will keep you inspired as you are progressing towards a healthier you.

In addition to improving your health and, ultimately, your shape, one of the many benefits you should reap from exercise is enjoying the experience of moving your body in a pleasurable way. As a plus-size person, do not be afraid to claim your rightful space in fitness studios. You have the same rights to enhance the quality of your life and, rest assured, you will not be subject to societal bias. Rather, you will likely get support and encouragement from your classmates, which will keep you steadfast on the path toward success.

The benefits of regular exercise are well documented physiologically, psychologically, socially and spiritually. Remember that the past does not equal the present and that the exercise industry has progresses significantly in recent years. Instructors are more qualified; there are more tools and props to work with. More is known about safety and the environments have been enhanced. There is no time like the present to get moving.

Kelli Calabrese M.S., C.S.C.S, has Masters Degrees in both Cardiac Rehabilitation and Exercise Science. She holds 17 fitness- and nutrition-related certifications and has owned and operated her own fitness centers for 14 years.