Hobby horsing is considered a legitimate sport because the athletic activity is performed by the person, not by the toy horse.

It has many of the features normally associated with organised sport:

Physical skill: competitors run, jump, accelerate, turn, balance and coordinate their movements while carrying the hobby horse.

Technical skill: dressage involves precise movements, transitions and sequences; show jumping involves navigating a course and clearing obstacles.

Rules and judging: official competition rules specify how events are conducted and how performances are assessed.

Competition: there are national championships, international competitions and qualifying events. The 2026 Finnish championships, for example, include show jumping classes from 50 cm through 100–110 cm and multiple dressage classes.

Training: participants practise specific techniques and routines, rather than simply pretending to ride a horse.

Organisations: the International Hobbyhorse Federation exists specifically to develop the activity, coordinate organisations and establish international competitive standards.

The interesting distinction is that hobby horsing isn't really “horse riding without a horse.” It's an independent physical discipline inspired by equestrian sports. In show jumping, for example, the athlete actually has to propel their own body over the obstacle while controlling the hobby horse.

So the argument for calling it a sport is basically:

skill + physical exertion + rules + training + measurable performance + competition = sport.