title: Effects of long term Tai Chi practice and jogging exercise on muscle strength and endurance in older people.
abstract: OBJECTIVE
  To investigate the influence of regular Tai Chi (TC) practice and jogging on muscle strength and endurance in the lower extremities of older people.
  
  
  METHODS
  Twenty one long term older TC practitioners were compared with 18 regular older joggers and 22 sedentary counterparts. Maximum concentric strength of knee flexors and extensors was tested at angular velocities of 30 degrees/s and 120 degrees/s. Ankle dorsiflexors and plantar flexors were tested at 30 degrees/s and the dynamic endurance of the knee flexors and extensors was assessed at a speed of 180 degrees/s.
  
  
  RESULTS
  The differences in the muscle strength of the knee joint amongst the three experimental groups were significant at the higher velocity. The strengths of knee extensors and flexors in the control group were significantly lower than those in the jogging group and marginally lower than those in the TC group. For the ankle joint, the subjects in both the TC and jogging groups generated more torque in their ankle dorsiflexors. In addition, the muscle endurance of knee extensors was more pronounced in TC practitioners than in controls.
  
  
  CONCLUSIONS
  Regular older TC practitioners and joggers showed better scores than the sedentary controls on most muscle strength and endurance measures. However, the magnitude of the exercise effects on muscles might depend on the characteristics of different types of exercise.
authors.affiliation: The Chinese University of Hong Kong, Shatin N T, Hong Kong.
authors.forename: D Q
authors.initials: DQ
authors.lastname: Xu
authors.forename: J X
authors.initials: JX
authors.lastname: Li
authors.forename: Y
authors.initials: Y
authors.lastname: Hong
mesh_terms: D000367:Age Factors; D000368:Aged; D000843:Ankle Joint / Q000502:physiology; D005260:Female; D006801:Humans; D007590:Jogging / Q000502:physiology*; D007719:Knee Joint / Q000502:physiology; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D026302:Tai Ji; D013997:Time Factors