Romans 15:1 KJV
We then that are strong ought to bear the infirmities of the weak, and not to please ourselves.
We ought to use whatever strength we have to minister to the infirmities of others and not for our own pleasure. That strength may take many forms;
Which may be faith and knowledge of the Word of God. In this case we ought to search for means to share that Word with others.
Physical strength and health
In which case we may be used to care for others who have needs rather than using our health for pleasures such as sports activities and many recreations.
In which case we ought to use our money first to minister to our church, secondly to the poor and then to meet the needs of our family (realizing that God meets our needs and not the work).
Rather than attempting to discern who is strong and who is weak, it would be better to seek out those areas where we are strong, where we are capable of ministering to another and, rather than using whatever "strength" we have for our own pleasure, use it rather for the sake of another.