Table 2. Correlations among the time (6:00 to 9:00), level of activity, sleepiness, and fatigue.
Sleepiness | Sense of fatigue | LF/HF | HR | Level of activity | ||
---|---|---|---|---|---|---|
Time (6:00 to 9:00) | Nap | r=0.049 n.s. | r=0.157 n.s | r=–0.565** | r=–0.759*** | r=–0.696*** |
No nap | r=0.112 n.s. | r=0.129 n.s. | r=0.007 n.s. | r=0.537** | r=–0.209 n.s. | |
Level of activity | Nap | r=–0.155 n.s | r=–0.039 n.s. | r=0.589*** | r=0.594** | – |
No nap | r=–0.063 n.s. | r=0.069 n.s. | r=–0.560*** | r=0.315 n.s. | – |
*: p<0.05, **: p<0.01, ***: p<0.001. n.s.: not significant, r: correlation coefficient.