The popular Nintendo Wii Fit is not as effective at burning calories and improving health as regular fitness training and exercise, according to a recent study.

The American Council on Exercise (ACE), America's leading authority on fitness, analysed the six most aerobically challenging activities featured in the Wii Fit - including Free Run, Advanced Step, Super Hula Hoop and Rhythm Boxing - and found the results "underwhelming".

Cedric Bryant, ACE's chief science officer, said the intensity of most exercises on the Wii Fit proved to be milder than expected.

"While we found that playing the Wii Fit burns twice as many calories as a sedentary video game, the outcome of the study suggests that Wii Sports - which includes tennis, boxing, golf and bowling - is a better option for helping consumers meet minimum intensity guidelines for exercise," said Mr Bryant.

Mr Bryant added that only the Dancetown study showed "a significant increase in exercise intensity and calorie expenditure" for all subjects as they participated in each of the program's increasingly difficult modes.

In October it was announced that the Wii Fit Plus was the first ever computer game to gain approval from the Department of Health.