Another aspect of the Curves ® workout that affirms the new participants' exercise efforts is the limited instruction and supervision during the training sessions. Our research on the physiological and psychological responses to a beginning strength training program clearly indicates that a less intense instructional approach may be more beneficial from an exercise adherence perspective (Westcott et al 2003). In our study, the beginners who received more exercise instruction performed better physiologically (greater fitness gains), but those who received less exercise instruction did better psychologically (more exercise enjoyment). While both training outcomes are important, it is essential for new participants to enjoy the exercise experience and feel comfortable in the exercise environment. Their perceived level of competence and confidence in performing the workout seems to be an important consideration for training compliance, and too much corrective feedback or even detailed directions may have negative consequences.
In my opinion, Curve® is extremely well-suited for introducing inactive women to an appropriate beginning exercise program that should positively impact their personal health, fitness and appearance. However, without an option to progress to more challenging exercise programs, the beneficial training effects may plateau well below their potential. In other words, the Curves® approach provides a good start, but a higher-level graduate program would appear to be advisable for continued progress and participation.
Healthy Inspirations® Study
Casey Conrad, founder and CEO of Healthy Inspirations® recently conducted a research study to determine if a more challenging second-level strength training program would benefit her members. Like Curves®, Healthy Inspirations®, members begin with hydraulic strength exercise because it is quick to learn and easy to perform. However, upon reaching a plateau in their introductory program, participants are encouraged to use weightstack machines (Nautilus 2 ST line) for their strength training component.
Weightstack machines provide a solid resistance with both concentric and eccentric muscle actions on every repetition. Repetitions are performed more slowly on weightstack machines than on hydraulic equipment, which produces more muscle tension and enhances the strength-building stimulus.
In this study, the subjects were 32 Healthy Inspiration® members (23 women and 9 men) with a mean age of 49.9 years. They all trained three days per week for a period of seven weeks, using eight standard weightstack machines that collectively addressed all of the major muscle groups. Each strength exercise was performed for one set with a weightload that fatigued the target muscles within eight to 12 repetitions. The resistance was increased by approximately five percent whenever 12 repetitions were completed.
My fitness testing staff conducted the pre and post-training assessments on the research program participants. As presented in Table 1 the 32 subjects averaged 4.5 pounds less fat weight and 3.0 pounds more lean (muscle) weight, for a 7.5-pound improvement in body composition, and a 2.5 percent reduction in percent body fat. They also experienced small improvements in resting blood pressure.
Table 1. Pre and post-training data for participants who completed the seven-week strength training program (32 subjects, mean age 49.9 years).