This can be guessed, but it is not necessarily completely accurate.

Because a person excludes the time outside of sleep and work in a day, in fact, he doesn't have much time at his disposal. However, insisting on fitness exercise shows that he is very self-disciplined. He may not spend time doing other things, but he must exercise. But there is still no evidence to judge whether he is single from this angle, because there have been examples of two couples exercising together. Fitness exercise does not affect their feelings, but can promote them. After all, it is very rare to have the same hobbies.