Updated at 6.51pm: The Consumer Council on Friday expressed concern about two weight-loss devices available in Hong Kong.
The council was releasing its latest findings on a horse-riding exercise machine and vibrating belts ? both of which are designed for slimming.
The horse-riding machine imitates the movements of a horse. The slimming belt is installed with electric motors and vibrates around the body.
The two products, which cost thousands of dollars each, have recently become popular in Hong Kong.
A council spokesman said experts from the Hong Kong Physiotherapy Association and the Hong Kong Orthopaedic Association believed the effectiveness of the horse-riding machine was only equivalent to ?mild aerobic exercise?.
He said its effectiveness would depend on the speed, intensity and frequency of use.
The horse-riding machines are designed to enhance functions of the heart and lungs ? as with other forms of aerobic exercise. Although regular aerobic exercise could help the body burn calories, the council concluded the horse-riding machine was not suitable for some people.