The basic exercise program is two months long, which seems to be an ideal introductory period for previously sedentary adults. Over 90 percent of the participants rate their exercise class as highly satisfying, and about 80 percent join the YMCA after completing the program. In other words, the eight-week training period is sufficient to turn many inactive women and men into regular exercisers.

One reason for the positive lifestyle change is the excellent results attained by the program participants. As shown in Table 1, the 383 men lost 6.4 pounds of fat weight and gained 3.7 pounds of lean (muscle) weight for a 10-pound improvement in body composition, and the749 women lost 3.4 pounds of fat weight and gained 1.7 pounds of lean weight for a 5-pound improvement in body composition. At the same time, the men reduced their average resting blood pressure by 4.5 mm Hg, and the women reduced their average resting blood pressure by 3.1 mm Hg.

Another finding is that the younger (ages 21-40), middle (41-60), and older (61-80) adults all attained similar improvements in body composition and resting blood pressure. Just as important, those who began the program in the poorest shape (with the highest percentage of body fat) experienced the most fat loss and lean (muscle) gain. That is, the adults who had the greatest fitness needs made the greatest improvements.

A practical reason for the success of the basic exercise program is the time-efficient training requirements. The participants did only 25 minutes of strength exercise and 25 minutes of aerobic activity each training session. Even more helpful for many time-pressured adults, only two workouts a week were necessary for excellent results. As shown in Figure 1, the two-day and three-day exercisers made similar improvements in body composition and resting blood pressure after eight weeks of training.

In addition to an effective and efficient training program, most beginning exercisers appreciate small classes and attentive instructors. We conduct all of our classes in a separate exercise area, with six members and two instructors per class. This closely supervised setting facilitates the training process and produces an 85 percent compliance rate among program participants.

We have found that most adults can make time for a well-designed exercise program that takes a sensible and systematic approach to strength training. When the proper exercise principles are applied, excellent results can be achieved in just two 25-minute strength workouts per week.

The Strength-Training Program
The excellent results attained by the 1,132 research program participants required only 25 minutes of strength exercise, two or three days per week. The recommended strength-training protocol, based on the American College of Sports Medicine guidelines, is as follows:

Training Frequency
The standard recommendation of three nonconsecutive days per week is sound, and should be followed whenever possible. However, in a large training study I completed this year, the 416 subjects who strength-trained twice a week achieved almost 90 percent as much strength and muscle gain as the 716 subjects who did strength workouts three days a week. For people who have a hard time getting to the gym three times a week, it is good to know that two strength workouts per week produce nearly as much training benefit.

Training Sets
Two separate studies have found that one-set training and three-set training are equally effective for increasing upper-and lower-body strength. If training time is limited, it is good to know that single-set strength exercise is just as productive as multiple-set workouts.