I agree that everyone should make an effort to exercise and socialize (as well as other difficult but rewarding tasks). But it's undeniable that different people respond to these things differently. Some people feel energized after difficult exercise, others feel drained. Some people find socialization exhilarating, others find it exhausting.

Encouraging someone to push past their comfort zone is helpful. But it seems less helpful to imply that you know more about the bounds of their comfort zones than they do, or that their comfort zone must simply be a cultural construct because it doesn't match yours.