Relative to the general US population, American Birkebeiner Survey participants display very low levels of obesity, lower than average BMI, high self-reported health status, and a high prevalence of healthy lifestyle behaviors, including regular physical activity.
The prevalence of obesity in the United States is currently estimated at 35.6%, and with a national mean BMI of 26.7, the average American is overweight (BMI between 25 and 29.9) [1]. In contrast, the average BMI for Birkie participants is 23.8 and the number of Birkebeiner participants with a BMI ≥30 is only 3.23%. While the low incidence of obesity among Birkie skiers may be due in large part to self-selection by current athletes, we hypothesize that participation in a race culture may play help individuals who are trying initiate and maintain weight loss.
The health benefits of physical activity may to extend to other healthy behaviors as well. Several studies have shown that individuals can reduce their risk of heart attack or stroke by between 40 and 80% if they adopt four healthy lifestyle characteristics (HLCs): (1) don’t smoke, (2) eat five fruits and vegetables per day, (3) maintain a BMI <25, and (4) exercise >150 min/week. Yet, only about 3% of the US population adheres to all four HLCs [12, 13]. Not only do our data show that Birkie participants report higher prevalence of each of the HLCs than the general population, but nearly five times as many (15%) report routine adherence to all four of these healthy lifestyle behaviors which suggests a potential reduction in the risk of cardiovascular events among Birkie athletes (see Fig. 1). We hypothesize that the incidence of cardiovascular events among Birkebeiner skiers would be lower than non-skiers in the US population.
Our data underscore the commonly observed coexistence of vigorous physical activity and higher levels of other beneficial health behaviors [14,15,16]. Skiers in the American Birkebeiner participate in a communal fitness lifestyle that may discourage behaviors such as smoking, excess alcohol use, poor diet, overweight and obesity, and physical inactivity, and that may encourage physical activity and a host of other healthy behaviors which improve the ability to perform well in community fitness events. We hypothesize that participation in the fitness culture surrounding the American Birkebeiner reinforces healthy lifestyle behaviors relative to non-participation.
Strengths and limitations
This study is the first to report health behaviors of Nordic skiers in the United States and one of the few that describe these health habits in endurance athletes. We had a large sample size that allowed evaluation of multiple factors. We modeled our survey to measure constructs similar to those in national surveys to allow comparison and hypothesis generation.
Nordic skiing can be costly and our study participants reported higher socioeconomic status, higher levels of educational attainment, and more leisure time for training. The Nordic origins of cross-country skiing and the trails in the United States where it can be practiced currently attract predominantly white participants although there are exceptions to this trend. While Birkie skiers appear to have fewer barriers to physical activity related to cost, sport knowledge, ease of access, and leisure time, these demographic realities do not negate the high levels of physical activity and health behaviors reported in this subgroup of the US population. Healthy individuals are more likely to participate in Nordic ski races which introduces a source of bias that tempers the conclusion that race cultures alone strictly cause improved fitness.
Application of these results to individuals with different demographics and background must be made with caution. Disadvantaged populations may not experience the low levels of obesity and high prevalence of healthy lifestyle behaviors reported here either because of pre-existing conditions, because participation in endurance sports is not the cultural norm, or because the barriers to preparation and participation for endurance events are currently insurmountable. Also, we were unable to collect physiological data and we did not solicit information on formal medical diagnoses besides mood disorders and arthritis. This limits our ability to objectively describe physical activity, adverse health outcomes among citizen endurance athletes and leaves us to speculate based on risk reduction estimates reported in the literature regarding self-reported health behaviors.
These survey results are important for preventive medicine and public health because they document elevated self-reported health outcomes in a group defined by participation in a fitness culture. These individuals report elevated adherence to preventive health recommendations for physical activity, diet, and other healthy lifestyle characteristics. Another result of the survey is the identification of powerful fitness cultures that often surround competitive endurance events such as the American Birkebeiner. Finally, the influence that fitness cultures may exert on individuals and communities adds weight to preventive medicine and public health guidance that emphasizes group activities over individualized plans for health behavior change.