BAKERSFIELD, Calif. -- Active video games such as the Nintendo Wii-Fit and Sii-Sports varieties are a popular pastime for kids and adults alike.

But how much exercise are they truly providing? The answer is probably not much.

Nintendo itself funded a study into its active Wii video games, in which researchers tested energy expenditure in 12 men and women as they played each type of sport.

Volunteers tried out everything from yoga and bowling to golf and tennis. But just 14 out of 46 activities reached the level of moderate exercise, equivalent to walking.

The Wii boxing and a single-arm handstand required the most energy out of the group. However, none of the activities reached the level of vigorous exercise that you get from running, biking or swimming.

Government guidelines state that healthy adults should get at least 30 to 60 minutes of moderate exercise on most days of the week. Exercise should be vigorous enough to raise your heart rate for a minimum of 20 minutes.