title: Cardio-pulmonary fitness test by ultra-short heart rate variability.
abstract: OBJECTIVE
  It is known that exercise induces cardio-respiratory autonomic modulation. The aim of this study was to assess the cardio-pulmonary fitness by ultra-short heart rate variability.
  
  
  METHODS
  Study population was divided into 3 groups: Group-1 (n = 40) consisted of military sports man. Group-2 (n = 40) were healthy age-matched sedentary male subjects with normal body mass index [BMI = 19 - 25 kg/m(2)). Group-3 (n = 40) were healthy age-matched obese male subjects [BMI > 29 kg/m(2)). Standard deviation of normal-to-normal QRS intervals (SDNN) was recorded over 15 minutes. Bruce protocol treadmill test was used; and, maximum oxygen consumption (VO(2)max) was calculated.
  
  
  RESULTS
  WHEN THE STUDY POPULATION WAS DIVIDED INTO QUARTILES OF SDNN (FIRST QUARTILE: < 60 msec; second quartile: > 60 and < 100 msec; third quartile: > 100 and <140 msec; and fourth quartile: >140 msec), progressive increase was found in VO(2)max; and, SDNN was significantly linked with estimated VO(2)max.
  
  
  CONCLUSIONS
  In conclusion, the results of this study demonstrate that exercise training improves cardio-respiratory autonomic function (and increases heart rate variability). Improvement in cardio-respiratory autonomic function seems to translate into a lower rate of long term mortality. Ultra-short heart rate variability is a simple cardio-pulmonary fitness test which just requires 15 minutes, and involves no exercise such as in the treadmill or cycle test.
authors.affiliation: Sport Physiology Research Center, Baghiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Arsalan
authors.initials: A
authors.lastname: Aslani
authors.forename: Amir
authors.initials: A
authors.lastname: Aslani
authors.forename: Jalal
authors.initials: J
authors.lastname: Kheirkhah
authors.forename: Vahid
authors.initials: V
authors.lastname: Sobhani