Table 4. Extraction of factors via factor analysis.

Item No.	Tiredness after physical activity	Cognitive dysfunction	Residual fatigue
1. Tired for a long time after activity	0.76	0.12	0.22
2. Poor concentration	0.40	0.65	-0.02
3. Muscle tiredness after activity	0.82	0.15	0.22
4. Headaches	0.24	0.20	0.59
5. Sleep for a long time	0.71	0.18	-0.16
6. Muscle aches after activity	0.57	0.11	0.48
7. Sleep poorly	0.08	0.14	0.77
8. Problems with speech	0.05	0.74	0.37
9. Memory is poor	0.13	0.84	0.07
10. Muscle pain even at rest	0.40	0.25	0.52