He has backup

In many ways, having a partner in the gym is good. They can support you on the squat machine and bench press, and motivate you when the workout gets a bit tiring. But the father seems to be looking for a different kind of partner by taking his daughter in a stretcher.

Many people are naturally motivated by their children to become a better version of themselves. Perhaps having his daughter around will motivate him to try harder and achieve even better results. He also sets a good example for her, which will make her train too.