(CNN) -- When the Nitendo Wii Fit debuted in 2007, experts were skeptical about the system's health benefits.
Yes, active video games were better than the alternative: sitting down playing regular video games for hours. But were they really a replacement for physical exercise?
Since then numerous studies have been done on active video gaming systems, including the Wii, Microsoft¹s Kinect and the PlayStation Move. The latest, a meta-analysis done by researchers at Michigan State University, evaluates the results of 16 related studies to determine if active video games -- or exergames -- provide the same cardiovascular benefits as a nonvirtual workout.
The short answer is kind of, says study author Wei Peng.
"Findings suggest that while those games are good if you want to motivate those that are really sedentary... we cannot really rely (only) on these games."
Peng and her colleagues analyzed the energy expenditure, heart rate and oxygen consumption of study participants playing exergames. They found the energy used was equivalent to the energy used doing light-to-moderate intensity activity, although games that involved the whole body, including the lower half, exerted a lot more energy than those that required only simple arm movements.
Participants' heart rates and oxygen consumption also increased significantly with whole-body engagement.
But even the most active games don't necessarily give your body a full workout, Peng says. Light-to-moderate intensity activity is not the moderate-to-vigorous intensity activity recommended by government agencies like the Centers for Disease Control and Prevention.
The results support the National Council on Strength and Fitness' stance on playing active video games.
"In most cases you'll find it's better than watching television, or as a replacement for other sedentary behaviors, but most (studies) agree it should not replace play and sport activities," executive director Brian Biagioli wrote in an e-mail.
For this reason, active video games may be best for the elderly population, according to the National Council on Strength and Fitness. A study published in 2010 found exergames improved mobility, dexterity, coordination and provided a distraction from pain in nursing home residents.
"This is a good tool for them," Peng says. "They really cannot engage in vigorous levels of activity. They may go for walks but in the wintertime it's kind of hard, so video games are especially good."
It's also less intensive than going to the gym, GameSpot editor Guy Cocker adds. "My mom (plays) when she's not really wanting to go out. She just prefers to work out at home."
Cocker recently lost nearly 20 pounds playing "UFC Personal Trainer." The Ultimate Fighting Championship game trains players in mixed martial arts.
More intense than most exergames, "UFC Personal Trainer" is still not enough to sustain weight loss, Cocker says.
"The key to this stuff is that you can't just use that product alone. You have to use it in conjunction with regular exercise and healthy eating."
Cocker says the most popular exergames this season include "UFC," "Your Shape" and "MiCoach." Also selling well are dance games like "Dance Central" and "Zumba" and athletic games such as "EA Sports Active." He suggests looking for gaming systems that track your whole body's movement like the Kinect if you're hoping to break a sweat.
The best aspect of active video games, Peng says, is that they're psychologically motivating. Oftentimes children don't want to exercise. But studies show that after playing exergames, children said they didn't feel tired, even though they had used the same amount of energy as doing a moderate workout.
"This is especially important for sedentary kids," she says. "It's an important barrier. They get so immersed in the game world they kind of forgot about (the workout). That's the beauty in it."
So if you're thinking about purchasing an active video game system for your kids this holiday season, go ahead. Just make sure to pick one up for Grandma, too.