Keeping your brain fit is important, and the study isn't arguing that. The way that these games do it is not useful. Just liking training running will make you

Keeping your brain fit is important, and the study isn't arguing that. The way that these games do it is not useful. Just liking training running will make you good at running, training those puzzles will make you good at... those puzzles. That's not what those game companies sell it as, people want better general intelligence and instead they are just getting really good at matching shapes or solving crosswords. In your football example, a squat is full body exercise that strengthens numerous different muscle groups. These "brain training games" are not full mind exercises.