Modern society has many benefits, but a pervasive consequence of sedentary lifestyles is the serious acceleration of degenerative processes associated with aging. Adults who do not perform resistance exercise lose 3 to 8 percent of their muscle tissue every decade. Muscle loss leads to metabolic slowdown, which is largely responsible for an average fat gain of more than 15 pounds per decade. Most experts recommend diet and exercise as the best approach for addressing the obesity epidemic, but this has not proven very effective, especially for permanent weight loss. The major problem with diet programs is that most dieters do not eat enough calories to attain desirable levels of physical activity and to maintain a normal metabolic rate. The result is a relatively rapid loss of body weight, but 25 to 50 percent of the weight loss comes from muscle tissue. This obviously exacerbates the initial issue of too little muscle, and eventually leads to full weight regain in more than 90 percent of dieters. The major problem with exercise is that less than 5 percent of American adults meet the minimum standard of 30 minutes of moderate physical activity (equivalent to a relatively slow walk) on a regular basis (five days per week). Those who do exercise typically perform aerobic activity that enhances cardiovascular fitness but does not reverse or prevent muscle loss. Very few men and women perform effective resistance exercise, which is essential for rebuilding muscle and increasing resting metabolism. As you may recall from previous Keeping Fit columns, we teamed up with Boston Medical Center's Dr. Caroline Apovian, arguably the premier medical doctor/nutrition expert in the nation, to study the combined effects of her exceptionally well-designed diet plan with our well-researched exercise program. Apovian's nutrition plan provided a moderate amount of daily calories to avoid muscle loss and metabolic decline, as well as to ensure enough energy for beneficial physical activity. Her diet emphasized a relatively high protein intake to facilitate muscle development, as well as unlimited fruits and vegetables to supply high levels of essential nutrients without high calorie counts. Our physical activity program combined the most productive resistance exercises with the most effective aerobic training to optimize muscle development, energy utilization and cardiovascular fitness. Based on our research study with the Air Force, we interspersed the resistance exercises with the aerobic activities. Our program participants performed three strength exercises for the leg muscles (one set each) followed by 5 minutes of recumbent cycling, then three strength exercises for the upper body muscles (one set each) followed by 5 minutes of recumbent cycling, then three strength exercise for the midsection/trunk muscles (one set each) followed by 5 minutes of recumbent cycling. For additional benefit, the 5-minute cycling sessions were performed in an interval training format, with 20 seconds of higher effort exercise alternated with 20 seconds of lower effort. More than 120 men and women completed the three-month exercise and nutrition study, and we recently analyzed the research data. The participants who performed the exercise program and followed the diet plan experienced much better results than those who did only the exercise program. Compared to the exercise-only group, the exercise and diet group achieved significantly greater reductions in body weight, body mass index (BMI), percent body fat, fat weight, waist circumference, systolic blood pressure and diastolic blood pressure. A third group of study participants did not want to lose weight but did want to rebuild muscle. This group did not reduce their daily calorie consumption, but they did increase their daily protein intake according to Apovian's formula. This group attained significantly greater increases in lean (muscle) weight than the exercise-only group, while maintaining their body weight due to an equivalent decrease in fat weight. This fall, we will conduct a similar study in our Exercise Science/Fitness Research Center at Quincy College. If you would like to learn more about this program, attend my presentation at 5:30 p.m. Wednesday, Aug. 29, at Quincy College's new location (Room 019, President's Place, 1250 Hancock St., Quincy). There is no charge or obligation, but call my office (617-984-1716) for seating purposes. Wayne L. Westcott, Ph.D., teaches exercise science at Quincy (Mass.) College. He has written 24 books on physical fitness.