The new Wii Fit U game provides an extension of slightly higher intensity activities (2.2 ± 0.4 to 4.7 ± 1.2 METs, mean: 3.2 ± 0.6 METs) in comparison with activities included in the previous Wii Fit + (1.3 ± 0.4 to 5.6 ± 1.1 METs, mean: 2.5 ± 1.0 METs, see ). While the new portable mini screen did not result in higher intensity activity in the present study (mean: 2.8 ± 0.5 METs), more MVPAs are still available through activities that use the traditional Wii game modalities (i.e., the Wii balance board and/or Wii remote). Surprisingly, the dance activities were found to be more intense than the aerobic activities (3.5 ± 0.5 vs. 3.0 ± 0.3 METs, respectively). One reason is that most of the dances included in the Wii Fit U package are actually practiced as dance aerobic exercises. Another reason is that the experiment was performed in beginner mode, which could have significantly lowered the intensity of the activities, including aerobics activities. These observations emphasize the necessity for health and fitness professionals not to rely on the manufacturer’s labeling, as the terminology does not necessarily reflect the effective intensities of the activities and may be misleading.
Attempting to increase PA in adults is a huge challenge that requires multifaceted strategies, and the present results may support the inclusion of AVGs in such strategies. In the present study, adult men expended more energy than women playing the same video game. However, this result cannot be explained by a difference in enjoyment as there was no difference in sPACES score between the sexes. Finally, no relation was found between enjoyment and intensity, which could be a critical point to maintain subject adherence over longer periods. Both the scientific field (via longitudinal studies) and the video game industry should address this important issue.
Significant proportions of Wii Fit U activities are still rated as light-intensity PA (7 of the 18 new Wii Fit U activities tested; 53 of 86 overall, see ). While these activities cannot be relied upon to fulfill current recommendations for PA (that should be MVPAs) , they may still be valuable to break sedentary times, or for seniors who would have greater benefits from light-intensity PA compared to their younger counterparts . However, further studies specifically designed to address these points are required.
Limitations and strengths
In the present study, all of the participants were invited to play at the beginner level, which may have lowered the game intensities. Indeed, Worley et al.  reported that playing Wii Fit games at an intermediate level significantly increased players’ EE. Another limitation is that the whole study was conducted in single-player mode. Multi-player modes, which may better reflect some real-life situations, have indeed been found to be more intense [14–16]. However, the use of the single-player mode allows a fairly objective evaluation of each game intensity, providing important information to the players and health and fitness professionals who wish to select AVGs for their usage. On the other hand, in real-life situations, adult players are invited to play games with their relatives and at intermediate to expert levels to have greater benefits from their AVG sessions. Finally, the relative small sample size, population age, and characteristics (i.e., inexperienced), as well as the 8-min format chosen for each activity, may prevent generalization of our results. However, one strength of the present study was the use of the same standardized protocol as described previously , allowing study-to-study comparisons, thus providing information about the evolution of Wii Fit series intensity.