It's just a strangely worded way of saying it. You can practice these forms without needing to retire and/or you can continue to practice them for however long you want whenever you retire. And it might not be a matter of starting, if you've already started before you retire.
Many people (myself included) practice yoga and other internal martial arts for at least 1-2 hours a day while also having a full-time job and family.
Many people (myself included) practice yoga and other internal martial arts for at least 1-2 hours a day while also having a full-time job and family.