Varying the Mode of Cardiovascular Exercise to Increase Adherence.(Statistical Data Included)

Many people do not engage in the recommended frequency, intensity and duration of exercise required to produce the psychological and physiological benefits of an exercise regimen. The purpose of this study was to investigate whether varying workouts over an 8-week period would increase adherence levels in sedentary individuals. Three different modes of exercise were examined: variable, static, and preferred Participants in the variable condition performed the same exercise for 2 weeks, at which time they changed exercises. Those in the static condition chose an exercise and remained with that single exercise for the duration of the study Participants in the preferred mode condition were not given a protocol as to when to change their exercise and were free to determine their mode of exercise. In addition to two measures of adherence, variables such as cardiovascular fitness, enjoyment, boredom, and physical self-efficacy were examined. Results indicated that the variable aerobic exercise regimen increased adh erence to the workout program as compared to the preferred mode. Furthermore, the participants in the variable program rated their workouts as more enjoyable. In addition, cardiovascular fitness increased across conditions, suggesting that all groups improved above baseline values. Boredom did not impact adherence, nor was boredom related to exercise program variability. No differences were found in physical self-efficacy over time, suggesting that it may remain stable over relatively short durations. Future research directions and implications are discussed with respect to the potential benefits of employing a variable exercise program.

Habitual physical exercise has long been praised for its positive impact on quality of life. The benefits of exercise range from psychological to physiological health conditions. For instance, researchers have suggested that regular exercise can reduce anxiety (Petruzzello, Landers, Hatfield, Kubitz, & Salazar, 1991), relieve both acute and chronic symptoms of depression (Camacho, Roberts, Lazarus, Kaplan, & Cohen, 1990), and increase self-esteem and physical self-concept (Spence, Poon, & Dyck, 1997). Additionally, it can control obesity (Brownell & Stunkard, 1980), hypertension (Boyer & Kasch, 1970), and diabetes (Vranic & Berger, 1979). Exercise can also be used in the prevention of cardiovascular disease (Oberman, 1985) and can decrease mortality and morbidity rates (Blair, Kohl, Paffenbarger, Clark, & Cooper, 1989). This aggregate body of research substantiates the importance of engaging in a habitual exercise regimen.

In spite of the myriad of health benefits of exercise, adult participation rates are disappointing. Recent reports indicate that greater than 60% of adults do not engage in the recommended amount of physical activity and 25% are completely sedentary. Furthermore, only 15% of adults engage in regular, vigorous exercise during leisure time (Centers for Disease Control, 1996). In addition, researchers have determined that approximately 50% of participants who begin an exercise program drop out within the first 3 to 6 months (Dishman, 1988). The severity and prevalence of sedentary lifestyles and non-compliance rates have motivated researchers to further investigate factors that impact exercise adherence.

Much of the research conducted in the area of exercise adherence can be classified into two categories: determinants and interventions. Determinants include factors such as demographics, personality characteristics, and barriers. For example, socioeconomic status, gender, age, race, and exercise history correlate with participation rates (e.g., Dishman & Buckworth, 1997; Welsh, Labbe, & Delaney, 1991). Characteristics of the individual may play a particularly large role in habitual exercise, as self-efficacy appears to be one of the most frequently identified psychosocial determinants of exercise adherence. Self-efficacy has been defined as the conviction that one holds in her/his ability to successfully execute the desired behavior required to produce a certain outcome (Bandura, 1997). This appears to be important in both the adoption (McAuley, 1992) and the maintenance (McAuley, Lox, & Duncan, 1993) of habitual exercise. McAuley, Coumeya, Rudolph, and Lox (1994) suggest that by implementing a selfefficacy intervention, exercise frequency increases. McAuley (1992) maintains that self-efficacy is a significant predictor of initial exercise adoption. Additionally, Rodgers and Gauvin (1998) revealed that self-efficacy levels discriminated moderately active from highly active participants. The importance of self-efficacy should not be underestimated when designing adherence interventions.

Enjoyment may also be a key in increasing exercise adherence rates among sedentary individuals. While it appears that many researchers tend to agree that enjoyment is a necessary ingredient to establishing a lifestyle of fitness, little research has been conducted in the area (e.g., Wankel, 1993). In fact, much of the existing research in exercise enjoyment has focused on the definition and measures of enjoyment instead of its relationship with exercise (e.g., Crocker, Bouffard, & Gessaroli, 1995; Kendzierski & Decarlo, 1991; Kimiecik & Harris, 1996; Wankel, 1997). However, evidence exists that those who enjoy exercise will continue with it as compared to those who do not enjoy exercise (Morgan, Shephard, Finucane, Schimmelfing, & Jazmaji, 1984) and that enjoyment motives are important for the maintenance of the activity (Ingledew, Markland, & Medley, 1998). At the opposite end of the spectrum, boredom is a frequently cited barrier not only to regular exercise (King, Taylor, Haskell, & Debusk, 1990), but als o to specific forms of exercise such as jogging (Vitulli & DePace, 1992). While the research in this area is scarce, it is becoming increasingly evident that finding ways of maximizing enjoyment while minimizing boredom may prove to increase exercise participation among sedentary individuals.

In addition to the abundance of research conducted on the determinants of habitual exercise, investigators also focus on interventions that may increase participation rates. For example, strategies such as telephone reminders (e.g., Lombard, Lombard, & Winett, 1995), relapse prevention (e.g., Marcus & Stanton, 1993; Simkin & Gross, 1994), and goal setting (e.g., Gallucci, 1995; Martinet al., 1984; Perkins, Rapp, Carlson, & Wallace, 1986) appear to have a positive affect on exercise adherence. Other interventions that have been successful at increasing exercise adherence rates include incentives and contracts (e.g., Neale, Singleton, Dupuis, & Hess, 1990; Robison et al., 1992), self-monitoring (e.g., Weber & Wertheim, 1989), and home-based versus group-based programs (e.g., King et al., 1997, King, Haskell, Taylor, Kraemer, & DeBusk, 1991; King, Haskell, Young, Oka, & Stefanick, 1995; Perri, Martin, Leermakers, Sears, & Notelovitz, 1997). While this list is not exhaustive, it does indicate the abundance of re search designed to increase adherence levels.

These types of interventions have had a positive impact on exercise adherence, but many contain limitations. For instance, several interventions require either supervision or participation in a group, yet research strongly suggests that those engaged in exercise prefer to do so at home as compared to a formal group setting (King et al., 1997). Techniques such as relapse prevention, reinforcement, incentives, and fitness testing require the participant to attend meetings or exercise in a supervised setting. These types of interventions may favor only those who can afford to participate, obtain a membership to a gym, or work in a setting which offers access to a fitness facility. While other techniques such as telephone contact or mediated approaches (mailings, signs) allow the participant to exercise at home, they require the involvement of an outside party (Cardinal & Sachs, 1995, 1996). It may not be practical or realistic to offer these options to every adult who wishes to participate. Also, interventions such as these cannot continue indefinitely. Participants should be offered interventions on which they can rely for unlimited support.