Final answer:
The statement is false; Sailors checking on-board after the 10-week notification are not required to participate in the next cycle PFA, but may do so if the command allows and the Sailor agrees.
Step-by-step explanation:
If a Sailor checks on-board after the 10-week notification period, according to the instructions provided in the Physical Readiness Program, they are not required to participate in the next cycle's Physical Fitness Assessment (PFA). This is because they have not been given the opportunity to participate in the full duration of a command’s Physical Readiness Program prior to the PFA. Therefore, the statement is False; they do not have to participate in the next cycle PFA if they check in after the 10-week notification. However, commands may allow the member to participate if it is deemed beneficial and if the Sailor desires to do so.