A new study from the Lancet analysing data about the physical behavior and mental mood of over 1.2 million Americans found that physically active people feel just as good as those who don't do sports but who earn about $25,000 more a year. The paper shows that while those who exercised regularly tended to feel bad for 35 days a year, nonactive participants felt bad for 18 days more, on average.
However, the goldilocks principle is alive and well here too... "The relationship between sport duration and mental load is U-shaped," said study author Adam Chekroud of Yale University. The study found that physical activity contributes to better mental well-being only when it falls within a certain time frame. According to the study, three to five training sessions, each lasting between 30 to 60 minutes, are ideal per week. The mental health of those participants who exercised for longer than three hours a day suffered more than that of those who weren't particularly physically active.