This twin study concluded that exercise does not improve longevity, but that the same genetic factors determine both ageing and physical activity levels: https://www.nature.com/articles/srep18259 Essentially, non-identical twins with differing physical activity levels had different mortality (as you would expect), whereas identical twins with differing physical activity levels had the same mortality (big surprise!). Now, I am not convinced, but this paper is getting media coverage where I live, so would love to see this study get dissected and examined by Peter and the team.
In podcast 254 and AMA 47 you discuss the potentially mild inhibitor to hypertrophy imposed by cold therapy after weight training. The three studies referenced in the notes all studied the effects of cold therapy after training, but what about the effects of cold therapy prior to training? There seems to be some research indicating that cold therapy prior to weight training can increase testosterone, vis. the well-known Japanese study. Might this translate to improved muscle synthesis?