Abstract
We read with great interest the recently published article by Ruddick et al titled “Epidemiology of electronic mountain biking injuries: An unexplored emerging extreme sport.” 1 To the best of our knowledge, this is the first time that the topic of injuries associated with e-mountain biking has been addressed, and we congratulate the authors on this achievement.
We agree with the characterization of e-mountain biking as a rapidly emerging sport in the title. Over the past decade, it has experienced significant growth, establishing itself as a popular activity in mountainous areas. For instance, total bicycle sales in Austria increased to ∼500,000 in 2022, with 50% of the 212,000 mountain bikes sold being e-mountain bikes. 2 Additionally, a 2020 mountain bike survey conducted by the Austrian Alpine Association, with ∼15,000 participants, found that 22% of respondents owned an e-mountain bike. 3 The growing prevalence of e-mountain bikes in Austria is also reflected in the increasing number of related injuries. According to the Austrian Alpine Accident Database, the proportion of e-mountain bike injuries rose from 1% in 2005 to 11% in 2020. 4 These figures underscore the rapid adoption of e-mountain biking and highlight the importance of further research into the associated risks and injury patterns within this emerging field.
However, we do not entirely agree that the results of an online survey of 46 e-mountain bikers with mild to moderate injuries over an 8-mo period in Australia can be used a priori to classify e-mountain biking as an extreme sport. Extreme sports generally are defined as activities where a mistake or accident is highly likely to result in death, such as BASE jumping or rope-free climbing. 5 To date, no study has been conducted on severely or fatally injured e-mountain bikers that suggests that e-mountain biking poses a higher risk of injury or death than conventional mountain biking.
One reason this is not really an extreme sport is that it is practiced in a recreational setting by older people and people with lower levels of physical activity. 6 In contrast, compared with a conventional mountain bike, an e-mountain bike allows riders to cover longer distances at higher speeds and tackle steeper climbs with less physical effort.7,8 This enables them to ride down single trails more frequently, 7 but it also potentially may increase the risk of injury due to overestimating one's physical and technical capabilities. In addition, anecdotal evidence suggests that professional mountain bikers use e-mountain bikes during training to navigate highly technical sections of the trail without becoming overly fatigued. This allows them to repeatedly return and pedal through these sections, enabling them to develop their skills rather than being limited by physical exertion. However, the more frequently a person engages in an activity, the greater is their cumulative exposure to potential hazards, which can increase the likelihood of injury. Therefore, it is not surprising that the risk of injury in professional mountain biking is higher during training than during racing. 9
An e-mountain bike is a mountain bike equipped with a pedal-assist motor. This provides improved accessibility to the sport, particularly for older individuals and those with lower levels of physical fitness. It also has the potential to attract a higher proportion of female riders.1,6 In a survey by the Austrian Alpine Club, 75% of respondents identified the most significant positive effect of e-mountain biking as enabling individuals with health impairments or older adults to participate in mountain biking. 3 However, the absence of data on the e-mountain biking population at risk is particularly problematic because it hinders our ability to assess the actual risk.
To assess the risk of injury or fatality in a sport such as e-mountain biking or to compare it with another sport such as conventional mountain biking, a prospective cohort study must be conducted over a defined period. This approach involves collecting exposure data to calculate incidence rates for the respective sport.
Nevertheless, we recognise the valuable contribution that the authors have made to this emerging field, and we encourage further research into the epidemiology of e-mountain biking injuries. This is particularly important given the growing popularity of the sport and its unique rider demographics.