title: Changes in serum creatine kinase, leg muscle tightness, and delayed onset muscle soreness after a full marathon race.
abstract: BACKGROUND
  Muscle tightness (MT) is believed to be an important cause of injury for runners. This study evaluated the change of serum creatine kinase (CK), MT in the leg muscles, and delayed onset muscle soreness after running.
  
  
  METHODS
  We evaluated 11 college students who completed a full marathon race. Participants completed a questionnaire on the right quadriceps muscle soreness. The CK activity and MT (iliopsoas, rectus femoris, hamstrings, gastrocnemius, and soleus muscles) were measured. The time points for CK measurements were before; immediately after; and at 1, 2, and 5 days after the race. The time points for MT measurements were the same as for CK except MT was not measured one day after the race. The time points for muscle soreness analysis were before the race and then every morning and night for 5 days after the race.
  
  
  RESULTS
  Long-distance running led to significant increases in CK, MT, and muscle soreness. The CK levels peaked day 1 after the race. MT of iliopsoas peaked on day 5; of rectus femoris immediately after the race; and of hamstrings, gastrocnemius, and soleus on day 2. muscle soreness peaked at night on day 1. MT did not decrease to the pre-race levels on day 5. There were no significant changes but CK tended to correlate with the peak of MT of the rectus femoris (r=0.55, P=0.082) and hamstrings (r=0.57, P=0.065).
  
  
  CONCLUSIONS
  Long-distance running may cause muscle fiber microdamage that may consequently increase CK, MT, and muscle soreness.
authors: Graduate School of Sport Sciences, Waseda University, Saitama, Japan - michio-t@aoni.waseda.jp.
authors: Michio
authors: M
authors: Tojima
authors: Kensuke
authors: K
authors: Noma
authors: Suguru
authors: S
authors: Torii
mesh_terms: D000328:Adult; D003402:Creatine Kinase / Q000097:blood* / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007866:Leg / Q000502:physiology; D008297:Male; D009129:Muscle Tonus; D063806:Myalgia / Q000209:etiology*; D005082:Physical Exertion; D052097:Quadriceps Muscle / Q000187:drug effects* / Q000293:injuries*; D012420:Running / Q000502:physiology*; D011795:Surveys and Questionnaires
chemical_list: D003402:Creatine Kinase