More than a million teenage boys were tracked for 24 years by a group of Swedish experts of the BMJ Group. The purpose was to determine whether there is a corollary between building up their muscles and living longer. While the study led the analysts to note that muscle strength indicates general fitness, the effects of being less muscular were akin to other risk factors, such as obesity and high blood pressure, which may contribute to a shorter lifespan. So, it remains uncertain.
Over the course of the study, 26,145 (2.3%) of the men died. The leading single cause of death was accidental injury, followed by suicide, cancer, heart disease and stroke.