And even that would be similar to someone cycling uphill, supported by the wind. Using air currents is efficient, but requires there to be air currents to use.
Gliding is really efficient for the distance covered, however: rolling resistance of wheels and the air resistance of a (not as aerodynamic) person is higher (and hence less efficient) than birds.
That’s like comparing only to a person on a bike downhill
Maybe compare to birds tracking upwards air currents to move while hovering, as they actually maintain a low average energy expenditure while moving
And even that would be similar to someone cycling uphill, supported by the wind. Using air currents is efficient, but requires there to be air currents to use.
Gliding is really efficient for the distance covered, however: rolling resistance of wheels and the air resistance of a (not as aerodynamic) person is higher (and hence less efficient) than birds.