title: Effect of low-dose endurance training on heart rate variability at rest and during an incremental maximal exercise test.
abstract: We evaluated the effects of low-dose endurance training on autonomic HR control. We assessed the heart rate variability (HRV) of 11 untrained male subjects (36.8 +/- 7.2 years) at rest and during an incremental maximal aerobic exercise test prior to a 7-week preparatory period and prior to and following a 14-week endurance training period, including a low to high intensity exercise session twice a week. Total (0.04-1.2 Hz), low (0.04-0.15 Hz) and high (0.15-1.2 Hz) frequency power of HRV were computed by short-time Fourier transform. The preparatory period induced no change in aerobic power or HRV. The endurance training period increased peak aerobic power by 12% (P < 0.001), decreased the HR (P < 0.01) and increased all HRV indices (P < 0.05-0.01) at absolute submaximal exercise intensities, but not at rest. In conclusion, low-dose endurance training enhanced vagal control during exercise, but did not alter resting vagal HR control.
authors.affiliation: Department of Biology of Physical Activity, University of Jyväskylä, P.O. Box 35 (LL), 40014 Jyväskylä, Finland. kaisu.martinmaki@sport.jyu.fi
authors.forename: Kaisu
authors.initials: K
authors.lastname: Martinmäki
authors.forename: Keijo
authors.initials: K
authors.lastname: Häkkinen
authors.forename: Jussi
authors.initials: J
authors.lastname: Mikkola
authors.forename: Heikki
authors.initials: H
authors.lastname: Rusko
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000502:physiology*; D002395:Catecholamines / Q000097:blood; D005080:Exercise Test; D005583:Fourier Analysis; D006321:Heart / Q000294:innervation*; D006339:Heart Rate; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010807:Physical Endurance; D013997:Time Factors; D014630:Vagus Nerve / Q000502:physiology
chemical_list: D002395:Catecholamines; D019344:Lactic Acid