Physiological relevance and health cost benefits. Reply: ''Disputing the Claims for Physiological Fitness and Health Adaptations from Purposeful Training using Off-road Vehicles'' by Milburn et al.

Thank you for the opportunity to respond to the Letter to the Editor entitled ‘‘Disputing the Claims for Physiological Fitness and Health Adaptations from Purposeful Training using Off-road Vehicles’’ by Milburn et al. (2012). We have several concerns with this Letter. First, we take exception to the authors’ opening sentence in which they imply a conflict of interest and appear to be attempting to discredit our research through our association with the Canadian Off-Highway Vehicles Distributors Council (COHV). We stated quite explicitly in our article that ‘‘This study was supported through a research grant organized by the COHV which included funds from both private and government sources’’. The COHV had no involvement at any stage of the research or manuscript preparation. Let us be clear that our interest in off-road vehicle riding has been, and remains, purely scientific in relation to the physiological and health-related indices associated with acute and habitual physical activity participation. We will accept it as true that the authors’ Letter to the Editor is similarly concerned only with the current science presented, and is in no way influenced by their previously published opinions objecting to the environmental, social and financial aspects of this activity (Bissix and Medicraft 2008). Milburn and colleagues appear to have overlooked important aspects of our article and of pertinent basic physiology research, in relation to the health benefits of physical activity participation. All physical activity participation has inherent risks (Goodman et al. 2011)—some more than others, and informed decisions regarding participation are only possible through consideration of both the risks and rewards. As we have acknowledged previously (Burr et al. 2010a), we do not deny the important concerns in regard to potential traumatic injury (and other issues such as land use and environmental impact); however, these issues are not germane to the evaluation of the effects on physiological health, fitness and chronic disease risk. We feel that the authors’ suggestion to disregard the possible health benefits of this activity for reasons apart from the question at hand (i.e. ‘‘is the physical activity stimulus capable of stimulating changes in health?’’) to be misguided. Given their previous publication exploring ‘‘...the problems of beer consumption as well as the emerging evidence of benefit’’ (Preedy 2009), we think the authors can appreciate our belief that these outlying objections to the validity of our results are analogous to suggesting evidence of the beneficial cardiovascular health effects of modest alcohol consumption (Gaziano et al. 1993) be similarly ignored owing to the role of alcohol in traumatic injury, the environmental impact of producing and shipping wine, or the ill effects of alcohol abuse on health (Eckardt et al. 1981; Ogden and Moskowitz 2004). Certainly these are all areas of concern, but do not change the original evidence of an association with health from a physiological perspective. Milburn and colleagues’ suggested that ‘‘none of the data indicates that riders met the important threshold of a minimum of 10 min at moderate intensity to conform to ACSM guidelines’’ is simply incorrect. Intensity and Communicated by Susan A. Ward.