Depression is the leading cause of disability, as measured by years lived with a disability, and the fourth leading contributor to disease worldwide in 2000, according to the World Health Organization (WHO).

Fitness professionals should consider sending motivational e-mail messages to clients to help them stay on track with their exercise goals. In a study published in the July issue of Health Psychology (2007; 26 [4], 401–9), researchers found that feedback delivered via e-mail to participants in an exercise program increased short-term adherence as effectively as phone counseling and was potentially more effective than phone counseling in the long term.

Exercise improves depression. In fact, some studies even show that exercise is more effective than prescription antidepressants in preventing depression relapses (see Psychosomatic Medicine [2000; 62, 633–38]). To date, however, scientists have been unable to identify the causal mechanisms that would clarify how exercise helps.

Fitness professionals looking for referrals from healthcare practitioners should include naturopathic physicians in their network of contacts. Many individuals who prefer a more holistic approach to health care are choosing to use naturopathic physicians either in combination with conventional medical professionals or on their own.

Do you give your clients positive feedback as they work with you? Do you inform them of your particular job qualifications? If you answered yes, you are providing clients with information that boosts their self-confidence to succeed in training.

Regular participation in water exercise or tai chi can alleviate the pain and stiffness of chronic arthritis, according to a study published in Arthritis and Rheumatism (2007; 57 [3], 407–14). Australian researchers conducted a randomized, controlled trial of 152 older adults with chronic hip or knee osteoarthritis.

For many people, stress and weight gain go hand in hand. Researchers, however, have maintained that stress-related fatness is triggered indirectly by unhealthy habits like overeating, smoking or excessive alcohol consumption, originating from emotional discomfort. Georgetown University scientists have now discovered a direct biological connection between stress and obesity in mice in a study published in Nature Medicine (2007; 13, 803–11).