5Mark TR, Ainsworth BE, Jacobs DB, et al.Validation of the Stanford 7-day recall to assess habitual physical activity[J]. Ann Epidemilo, 2001 ( 11 ): 145-153.
6Welk G.Physical Activity Assessments for Health-Related Re- search[M]. Champaign, IL: Human Kinetics, 2002: 107-108.