>Not everyone is rich enough to have the time to exercise.

5 minutes is sufficient if you have good pain tolerance, and pain tolerance can be trained. There's a great deal of evidence that high-intensity interval training is effective for improving cardiovascular fitness.

Diet is admittedly more difficult, but even if you can't eat healthy food you can still benefit from exercise.

https://en.wikipedia.org/wiki/High-intensity_interval_traini...