Wow, I just read a great article on this topic, but it was so NSFW that I may not reshare it. The basic premise is sound and I’ve read other supporting research on the topic. Basically, there are a number of things that elevate testosterone production, help you lift heavier, feel less pain, and grow more muscle (for both men AND women). The simple act of squeezing the barbell really, really hard; angry music; cursing; sexual imagery; violent imagery; etc. all seem to have an effect.