News & Views from the Editor-in-Chief: Andrew M. Jones
There is plenty of interesting material in the July issue of MSSE but I have chosen to highlight three rather diverse articles. Firstly, in 'Association of Physical Activity with Incidence of Dementia is Attenuated by Air Pollution,' Raichlen et al. show that, while higher levels of physical activity are beneficial for reducing dementia risk, exposure to even moderate levels of ultrafine particulate matter air pollution may attenuate these benefits. Physical activity (PA) is recognized as one of the key lifestyle behaviors that reduces risk of developing dementia late in life. However, PA also leads to increased respiration, and in areas with high levels of air pollution, PA may increase exposure to particulate matter that are linked with higher risk of developing dementia. Minimizing air pollution exposure, especially for ultrafine particulate matter during PA, may improve dementia risk-reduction. This study advances the evidence that efforts to reduce exposures to ambient air pollutants will enhance brain health in older adults and identifies key environmental factors that may affect PA-related health benefits. Secondly, in 'Left Ventricular Adaptation to Exercise Training via MRI: Studies of Twin Responses to Understand Exercise THerapy (STRUETH),' Marsh et al. present cardiac magnetic resonance imaging outcomes from the STRUETH study. This randomised crossover trial compared the impact of three months of endurance versus resistance-based training, modalities previously associated with different types of cardiac hypertrophy (eccentric vs. concentric). Data from 72 young healthy subjects indicated that low responders to one mode can be high responders to the other, and that switching training prescription can optimise benefits. An interesting aspect of the study was that monozygotic and dizygotic twin pairs exercised concurrently, using matched interventions. Whilst correlations (heritabilities) performed on baseline data suggested a genetic contribution to variation in cardiac mass/volume, no correlations were evident in the changes induced by training. If confirmed by future studies, this suggests that shared and/or unshared environmental factors may play a more important role than genetics in determining the magnitude of cardiac response to exercise training, at least in the short term. Finally, in 'Altitude and Endurance Performance in Altitude Natives versus Lowlanders: Insights from Professional Cycling,' Mateo-March et al. assessed the influence of terrestrial altitude on actual performance in top-level cyclists who were altitude natives (AN) or lowlanders. While it is known that acute altitude exposure impairs endurance performance compared to normoxia to a lesser extent in AN than in lowlanders, relatively scarce data are available in world-class athletes, particularly professional cyclists who excel in Grand Tours. The results indicated that, compared to sea- or near sea-level, AN's performance was relatively well preserved at increasing altitudes up to 2000 m whereas in lowlanders performance impairments were already evident at 500 m. AN showed higher performance than lowlanders as altitude increased, particularly at altitudes above 1500 m. More research is needed to elucidate the mechanisms underlying the unique adaptations of cycling champions who are also AN, and to determine whether, and how, similar adaptations might be achieved by lowlanders.
Andrew M. Jones
University of Exeter