Sleep and academic performance of Portuguese Teenagers
Table 3: Leisure activities before bedtime and school performance
| Leisure activities | Yes | No | UMW | p |
| School performance | sort average | sort average | ||
| Watch tv/dvd/vídeo | 204,11 | 156,78 | 11691,000 | 0,000 |
| Study | 217,47 | 182,77 | 9680,000 | 0,012 |
| Computer use (games, internet, and so on) | 177,43 | 205,33 | 15338,000 | 0,013 |
| Listen to music | 180,98 | 197,20 | 16010,500 | 0,156 |
| Reading | 234,50 | 180,74 | 7693,500 | 0,000 |
| Going out with friends | 167,03 | 194,15 | 7976,500 | 0,083 |
| Play sports | 162,88 | 193,13 | 4814,000 | 0,131 |
| Have a hot drink | 191,33 | 190,26 | 12571,000 | 0,937 |