Physical activity is perhaps the most frequently given advice for weight loss. But, as we have reported here, there are rarely-mentioned adverse events from some forms of physical activity. In August, the CDC’s Morbidity and Mortality Weekly Report showed an alarming increase in mortality rates for cyclists aged 35-74 years old. The mortality rate, while down overall, increased nearly three-fold in this age group. Males accounted for 87% of all bicycle deaths in 2012.