Effective fitness instructors come in various shapes and sizes, but they tend to have a few characteristics in common. For example, good teachers typically provide concise exercise explanations and precise exercise demonstrations to help participants clearly understand the desired physical performance (1, 2, 3). In simplest terms, they have mastered the art of show and tell, and use their communication skills to educate and motivate their clients.

Another factor that influences participant behavior is positive reinforcement. Positive reinforcement may take many forms, including a smile, a pat on the back, a sincerely stated "good job", or acknowledgement of attaining a predetermined goal.

A related teaching technique is referred to as performance feedback, which requires specific instructor comments on the clients exercise execution. Checking a participant's heart rate, counting out leg press repetitions, saying, "your movement range is a little short," "your repetition speed is just right," and "your breathing pattern is perfect" are all examples of instructor feedback. Basically, the purpose of feedback is to tell clients what they are doing correctly or incorrectly with respect to posture, technique and other aspects of their exercise performance.

Taken together, these teaching behaviors (exercise explanations, exercise demonstrations, positive reinforcement, performance feedback) indicate a certain level of exercise focus. Instructors who give frequent exercise explanations, exercise demonstrations, positive reinforcement and performance feedback provide a high-focus exercise environment, whereas instructors who perform these behaviors infrequently provide a low-focus exercise environment. Research has been unclear as to whether high amounts of (often repetitive) feedback or low amounts of (often very specific) feedback are more beneficial to participants' physiological progress and/or exercise maintenance.

Experimental Research
Within the context of a more comprehensive research project, we recently studied the effects of high-focus and low-focus exercise environments on strength training performance in beginning adult exercisers. The study subjects were 71 men and women (27 to 84 years of age) who completed a 10-week strength training program for previously sedentary adults. All subjects completed detailed medical history questionnaires prior to acceptance in the research program. Each participant was carefully assessed (Microfit computerized fitness analysis) in a private testing room before and after the 10-week training period for the following fitness parameters: (1) bodyweight; (2) body composition; (3) resting blood pressure; (4) muscle strength; (5) and joint flexibility. Data was analyzed for significant within-group and between-group differences.

All of the subjects trained in small classes (3 to 6 participants), under close supervision (1 or 2 instructors), two or three days per week (Tuesdays and Thursdays or Mondays, Wednesdays and Fridays), in a private exercise room. All of the classes were one hour in length, during which the participants performed 12 resistance exercises for their major muscle groups and did approximately 20 minutes of moderate effort aerobic activity (treadmill walking or recumbent cycling).