If a doctor tells patients to go for a run a few times a week with no additional resources and training advice, the doctor just set the patient to fail. Because they will train ineffectively getting little benefit for a lot of effort. Some will get injured from overdoing it. Others will stop improving after just few weeks and then end in frustration.

If a particular method is not compatible with duties and needs of a normal employed person with a familly, then that method constitues a bad advice for such person.