title: Cardiorespiratory adaptation with short term training in older men.
abstract: The purpose of this study was to assess the rate of training-induced cardiorespiratory adaptations in older men [mean (SD), 66.5 (1.2) years]. The eight subjects trained an average of 4.3 (0.3) times each week. The walk/jog training was in two phases with 4 weeks (phase 1) at a speed to elicit 70% of pre-training maximal oxygen consumption (VO2max), and 5 weeks (phase 2) at 80%. Maximal exercise treadmill tests and a standardized submaximal protocol were performed prior to training, at weekly intervals during the training programme, and after training. VO2max (ml.kg-1.min-1) increased significantly over both phases: 6.6% after the first 4 weeks, and an additional 5.2% after the final 5 weeks. The weekly changes in VO2max over phase 1 were well fitted by an exponential association curve (r = 0.75). The half-time for the rate of adaptation was 13.8 days, or 8.3 training sessions. Over phase 2, the change in VO2max did not plateau and a time course could not be determined. Submaximal exercise heart rate (fc) was reduced a significant 10 beats.min-1 after the first 4 weeks, and further 6 beats.min-1 over the final 5 weeks. The fc reductions showed half-times of 9.1 days (phase 1) and 9.8 days (phase 2) (or 5-6 training sessions). The anaerobic ventilation threshold was increased 13.9% over the 9 weeks of training and the respiratory exchange ratio during constant load heavy exercise was significantly reduced; however, these changes could not be described by an exponential time course. Thus, short-term exercise training of older men resulted in significant and rapid cardiorespiratory improvements.
authors.affiliation: Faculty of Kinesiology, University of Western Ontario, London, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Govindasamy
authors.forename: D H
authors.initials: DH
authors.lastname: Paterson
authors.forename: M J
authors.initials: MJ
authors.lastname: Poulin
authors.forename: D A
authors.initials: DA
authors.lastname: Cunningham
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000368:Aged; D004562:Electrocardiography; D015444:Exercise; D005080:Exercise Test; D005221:Fatigue / Q000503:physiopathology; D006321:Heart / Q000502:physiology*; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D010806:Physical Education and Training; D012119:Respiration / Q000502:physiology*; D012129:Respiratory Function Tests