Consider hiring a personal trainer if you fall into any of the following categories:

You are completely out of shape and haven’t the slightest idea how to begin an exercise program. A trainer can acquaint you with all of the up-to-date exercise techniques and available aerobic and weight machinery. You are in a huge exercise rut and have been doing the same old routine for as long as you can remember. A trainer can show you variations on your day-to-day workout and make exercising more efficient and effective. You just plain lack the “umph” to exercise on your own. A trainer can help to push, motivate, and whip your butt into shape.

Seek out somebody with a B.S. (better yet, a Master’s degree) in exercise physiology, physical education, or kinesiology. You can also look for a certified fitness trainer, which means she has studied for and passed a comprehensive training exam. Some of the most reputable organizations that provide certifications include the following:

ACSM (American College of Sports Medicine) ACE (American Council on Exercise) NSCA (National Strength and Conditioning Association) AFAA (Aerobics and Fitness Association of America) NASM (National Academy of Sports Medicine)

Other comprehensive fitness certifications are offered at various universities. Most of these organizations offer a variety of certifications (aerobic instructor, yoga, and so on). Make sure your trainer is specifically certified in personal training or fitness instruction and that his or her certification is up to date. Interview a trainer before you actually set up an appointment to be sure you feel comfortable with his or her workout philosophy, personality, and fee scale. Rates vary tremendously, anywhere from $40 to $100 per workout. They can even run more than $200 if you’re looking for a “trainer to the stars.”