Wii Fit U intensity and enjoyment in adults

Sixteen Japanese men (n  =  8) and women (n  =  8) aged between 30 and 45 years old participated in this study. According to Nintendo commercials and packaging materials, sedentary young and middle age adults have indeed been identified as the main target audience for the Wii Fit series. The subjects did not report any exercise habits (here defined as at least 30 min of structured physical exercise twice per week during the previous year), and are consequently referred as sedentary elsewhere in this manuscript. Subjects had limited experience with Wii Fit (no experience with the tested activities) and were therefore considered as beginners. No training sessions were scheduled before the experimental day. Subjects did not report any chronic diseases.

The standardized metabolic chamber protocol was described in detail elsewhere [10]. Briefly, subjects performed the 18 new activities of Wii Fit U at the beginner level. Each activity was continued for 8 min to obtain steady-state EE. Two open-circuit indirect metabolic chambers (15000 or 20000 L) were used to measure the metabolic equivalents for each activity (METs) as an index of intensity. Chambers were equipped with a TV, a video game console, a table, and a chair. Temperature was controlled at 25°C and relative humidity was set at 55%. The oxygen and carbon dioxide concentrations of the air supply and exhaust were measured by mass spectrometry (ARCO-1000A-CH; Arco System, Japan). The flow rate exhausted from the chamber was measured by pneumotachography (FLB1; Arco System, Japan). The oxygen consumption and carbon dioxide production were determined from the flow rate of exhausted air and the concentrations of the inlet and outlet air of the chamber. Data were recorded every 12 s. EE was determined using Weir’s equation [9]. Finally, MET values were calculated from resting EE and steady-state EE during each Wii Fit U activity. Heart rate (HR) was monitored throughout the protocol (BIOVIEW1000A PB1811; NEC Medical Systems, Japan).

Finally, a short version of the physical activity enjoyment scale (sPACES) was completed after each activity. Five items from the original 18-item test were chosen. The same items had been used previously by Graves et al. (2010) in a similar protocol [11]. Each item is presented as a 7-point Likert-type scale. The responses for the 5 items were summed to give a score ranging from 5 to 35, and the percentage enjoyment score was then calculated [11].

Statistical analysis was conducted at three levels:

1. 1)

   For each activity: For intensity and enjoyment, the differences between activities and sexes were tested by two-way ANOVA with 18 repeated measures.

    
2. 2)

   For each activity category: In accordance with the manufacturer’s label, activities were classified into three categories (Figure 1): balance activities vs. dance activities vs. aerobics activities. The differences between these three categories were investigated by one-way ANOVA. The Student–Newman–Keuls test was used for post hoc analysis.

    
3. 3)

   For each game modality: Activities were assigned to one of the following modalities (2 modalities, see asterisk in Figure 1): new portable mini screen vs. other traditional Wii Fit game modalities (Wii remote and/or Wii balance board). The difference between the two modalities was tested by unpaired t test.

    

In addition, the correlations between intensity and enjoyment scores were investigated for women and men by the Pearson correlation test. METs values and enjoyment scores are shown in Figure 1 as means  ±  SD. Significance is shown as P  <  0.05 or P  <  0.001.

The protocol was approved by the Ethics Committee of the National Institute of Health and Nutrition and subjects gave their informed consent.

According to the repeated measures test, intensities were significantly different between activities (P  <  0.001). As indicated in Figure 1, the new Wii Fit U activities were distributed over a range from 2.2  ±  0.4 (Hula dance) to 4.7  ±  1.2 (Hip-hop dance) METs. Seven activities were classified as light-intensity PA (<3 METs) and 11 activities as moderate-intensity PA (3 – 6 METs). No activity was considered as vigorous PA (>6 METs). The average intensity was significantly higher in men than in women (3.5  ±  0.8 vs. 3.0  ±  0.5 METs, respectively, P  <  0.001; overall average: 3.2  ±  0.6). HR varied from 86  ±  14 bpm (Hula dance) to 109  ±  16 bpm (Hip-hop dance).

Dancing activities (3.5  ±  0.5 METs) were significantly more intense than balance (3.0  ±  0.2 METs, P  <  0.05) or aerobic activities (3.0  ±  0.3 METs, P  <  0.05). Finally, the activities with the new portable mini screen game modality were significantly less intense than those with the Wii remote or Wii balance board only (2.8  ±  0.5 vs. 3.4  ±  0.7 METs, respectively, P  <  0.001). These activities were rated as light-intensity PA (see asterisk in Figure 1).

Enjoyment scores were found to be relatively homogenous between activities, with the enjoyment scale varying from 55%  ±  21% to 74%  ±  13%. There were no significant differences between activities or sexes. Finally, no relations were found between intensity and enjoyment in women (R  =  –0.01) or men (R  =  –0.07).

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 [10]). 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 [10]). While these activities cannot be relied upon to fulfill current recommendations for PA (that should be MVPAs) [3], 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 [12]. However, further studies specifically designed to address these points are required.

While the new Wii Fit U tends toward more moderate-to-vigorous physical activity, the average intensity is still low (3.2  ±  0.6 METs). Users (including both players and health and fitness professionals) should be aware that active video games cannot be relied upon to entirely fulfill the recommendations for physical activity. Consequently, recommendations for sedentary people to engage in exercise should only be made for some selected games and must be considered as only one tool in a wider multifaceted strategy. On the other hand, innovative game modalities allowing more vigorous exertion could be developed to break the light-intensity physical activity/moderate-to-vigorous physical activity barrier more significantly and make these games more attractive for the purposes of health promotion.