The strength training program consisted of the following exercises performed on standard weightstack machines: (1) leg extension; (2) seated leg curl; (3) chest cross; (4) chest press; (5) pullover; (6) lateral raise; (7) biceps curl; (8) triceps extension; (9) low back extension; (10) abdominal curl; (11) neck flexion; and (12) neck extension. Each exercise was performed for one set with a resistance that permitted 8 to 12 controlled (6-second) repetitions. Whenever 12 repetitions were completed with proper form the weightload was increased by about 5 percent (typically 2.5 pounds).
Each participant in the a.m. classes trained under conditions of high exercise focus (frequent instructor interactions related to exercise performance), whereas subjects in the p.m. classes trained under conditions of low exercise focus (frequent instructor interactions on topics unrelated to exercise performance). The p.m. program participants experienced the same initial exercise instruction as the a.m. classes during the first 2 weeks of training. However, the p.m. instructors provided minimal amounts of exercise- focused information during the following 8 weeks (just enough to ensure proper training technique and progression). Although they interacted frequently with class members, the conversations were typically on topics other than exercise performance.
Of the 81 subjects who began this study, 5 dropped out of the a.m. classes (high-focus group) and 5 dropped out of the p.m. classes (low-focus group), leaving 71 participants who completed the 10-week training program. The training compliance rate (percentage of exercise sessions attended) was 85 percent for both treatment groups. The 45 subjects in the a.m. classes were about 80 percent female (mean age 59.7 years), and the 26 subjects in the p.m. classes were about 90 percent female (mean age 55.5 years). The high-focus group (a.m. classes) made significant improvements in percent fat, fat weight, lean weight, muscle strength, joint flexibility and diastolic blood pressure, whereas the low-focus group (p.m. classes) attained significant improvements in percent fat, fat weight, lean weight and joint flexibility. As shown in table 1, the high-focus group achieved significantly greater improvements than the low-focus group in percent fat
(-2.7% vs -1.7%) lean weight (+4.0 lbs. vs +2.2 lbs.), muscle strength (+9.0 lbs vs. +2.4 lbs) and diastolic blood pressure (-8.0 mmHg vs +1.5 mmHg).
Based on these findings it would appear that strength training under conditions of high exercise focus may produce more physiological improvements (e.g., percent fat, lean weight, muscle strength, diastolic blood pressure) than strength training under conditions of low exercise focus. In this study, higher levels of exercise focus were associated with faster rates of physical fitness attainment, whereas lower levels of exercise focus were associated with slower rates of physical fitness attainment.
It would therefore seem obvious that fitness instructors should provide high levels of exercise focus, and this is true if participants' physiological improvement is the top priority. However, psychological data from another aspect of this study offer a different perspective (6). Subjects who received low levels of exercise focus experienced significantly greater increases in revitalization and significantly greater decreases in feelings of physical exhaustion immediately after their strength training sessions. Such after-exercise changes on these feeling states have been associated with long-term exercise adherence (4, 5). Also, only the low-focus group had significant reductions in depression and tension over the course of the 10-week strength training program. These are important considerations with respect to emotional wellness and exercise adherence, especially for previously sedentary adults who need to establish an exercise habit for ongoing wellness.