Training Program

The strength training program was 14 weeks in length with an average of two exercise sessions per week. Each workout consisted of six strength exercises performed on five Nautilus machines as presented in Table 1.

Table 1.
Training exercises, target muscles, and Nautilus machines.

Each exercise was performed for one set of 8 to 12 repetitions to the point of momentary muscle fatigue. When 12 repetitions were completed with proper exercise form the weight load was increased by 5 percent.

Our definition of proper exercise form was relatively slow movement speed and full movement range. All training repetitions were performed in approximately six seconds, with two seconds for each lifting movement (concentric muscle action) and four seconds for each lowering movement (eccentric muscle action).

All training repetitions were executed through the full range of joint movement as determined by the subject's functional ability and freedom from discomfort.

The duration of the training sessions varied depending upon the subject's physical and cognitive abilities, but typically required between 15 and 20 minutes for completion. The actual time spent doing resistance exercise averaged six minutes per workout, as each of the six training exercises required about one minute of muscle activity (average 10 repetitions at approximately six seconds each).

Every exercise session was individually supervised by a trained instructor from the physical therapy staff. The instructors helped subjects get on and off the Nautilus machines, set the seat positions, and pin the weight stacks at the appropriate resistance level. They also provided participants with encouragement, feedback, and reinforcement throughout the workout.

RESULTS

Results of the strength training program were determined by analyzing the subjects' changes in body composition, muscle strength, joint flexibility, and functional ability.

Body Composition

The subjects' mean bodyweight changed from 130.2 to 131.2 pounds over the 14 week training period, representing a 1.0 pound increase. However, their mean percent fat decreased from 22.7 to 20.5 percent, for a 2.2 percent reduction in this parameter.

The subjects' mean fat weight decreased from 29.7 to 26.8 pounds, for a 2.9 pound fat loss. At the same time, their mean lean weight increased from 100.5 to 104.3 pounds, representing a 3.8 pound gain in lean tissue. It is assumed that most of the additional lean weight was in the form of muscle. All of the body composition results are presented in Table 2.

Table 2.
Mean changes in bodyweight and body composition over the 14_week training period (N=19).

Statistically significant difference (p<0.05).

MUSCLE STRENGTH

Both lower body strength and upper body strength improved as a result of the 14_week training program. As shown in Table 3, the subjects' mean 10 RM Nautilus leg press increased 47.2 pounds from 58.1 to 105.3 pounds. Their mean 10 RM triceps press increased 14.7 pounds, from 37.9 to 52.6 pounds.

Table 3.
Mean changes in lower body strength and upper body strength over the 14_week training period(N=19).

*Statistically significant difference (p<0.05).

JOINT FLEXIBILITY

All joint flexibility measures improved over the 14_week training period. The subjects increased their shoulder abduction by 9.4 degrees (100.0 to 109.4 degrees), and their hip flexion by 15.3 degrees (29.0 to 44.3 degrees). The joint flexibility changes are presented in Table 4.

Table 4.
Mean changes in flexibility measured at the shoulder joint and hip joint (seated) over the 14_week training period (N=19).

*Statistically significant difference (P<0.05).

FUNCTIONAL ABILITYThe subjects' mean FIM scores increased from 77.5 to 88.5, for an 11.0 point improvement over the 14_week training period. Their mean mobility distance increased from 122.2 to 209.4 feet, for a gain of 87.2 feet. The mean number of falls decreased from 1.1 during the previous 14 weeks to 0.7 during the training period, for a 0.4 reduction. The functional ability results are displayed in Table 5.

Table 5.
Mean changes in functional ability measures over the 14_week training period (N=19).

*Statistically significant difference (p<0.05).

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