title: Wet, volatile, and dry biomarkers of exercise-induced muscle fatigue.
abstract: BACKGROUND
  The physiological background of exercise-induced muscle fatigue(EIMUF) is only poorly understood. Thus, monitoring of EIMUF by a single or multiple biomarkers(BMs) is under debate. After a systematic literature review 91 papers were included.
  
  
  RESULTS
  EIMUF is mainly due to depletion of substrates, increased oxidative stress, muscle membrane depolarisation following potassium depletion, muscle hyperthermia, muscle damage, impaired oxygen supply to the muscle, activation of an inflammatory response, or impaired calcium-handling. Dehydration, hyperammonemia, mitochondrial biogenesis, and genetic responses are also discussed. Since EIMUF is dependent on age, sex, degree of fatigue, type, intensity, and duration of exercise, energy supply during exercise, climate, training status (physical fitness), and health status, BMs currently available for monitoring EIMUF have limited reliability. Generally, wet, volatile, and dry BMs are differentiated. Among dry BMs of EIMUF the most promising include power output measures, electrophysiological measures, cardiologic measures, and questionnaires. Among wet BMs of EIMUF those most applicable include markers of ATP-metabolism, of oxidative stress, muscle damage, and inflammation. VO2-kinetics are used as a volatile BM.
  
  
  CONCLUSIONS
  Though the physiology of EIMUF remains to be fully elucidated, some promising BMs have been recently introduced, which together with other BMs, could be useful in monitoring EIMUF. The combination of biomarkers seems to be more efficient than a single biomarker to monitor EIMUF. However, it is essential that efficacy, reliability, and applicability of each BM candidate is validated in appropriate studies.
authors.affiliation: Krankenanstalt Rudolfstiftung, Postfach 20, 1180, Vienna, Austria. fipaps@yahoo.de.
authors.forename: Josef
authors.initials: J
authors.lastname: Finsterer
authors.affiliation: Medical Center, Tel-Aviv, Israel. vdrory@post.tau.ac.il.
authors.forename: Vivian E
authors.initials: VE
authors.lastname: Drory
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D002986:Clinical Trials as Topic / Q000379:methods; D015444:Exercise / Q000502:physiology*; D006801:Humans; D009043:Motor Activity / Q000502:physiology; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000378:metabolism*; D014835:Volatilization; D017155:Wettability
chemical_list: D015415:Biomarkers