INFLUENCE OF HIGH-INTENSITY INTERVAL TRAINING ON ADAPTATIONS IN WELL-TRAINED CYCLISTS

• Published in: Journal of strength and conditioning research 2005-08, Vol.19 (3), p.527-533
• Main Authors: LAURSEN, PAUL B., SHING, CECILIA M., PEAKE, JONATHAN M., COOMBES, JEFF S., JENKINS, DAVID G.
• Format: Article
• Language: English
• Subjects: Adaptation, Physiological; Adult; Anaerobic Threshold - physiology; Analysis of Variance; Bicycling - physiology; Exercise Test; Heart Function Tests; Humans; Male; Oxygen Consumption - physiology; Physical Education and Training - methods; Physical Endurance - physiology; Plasma Volume - physiology; Respiratory Function Tests; Space life sciences
• ISSN: 1064-8011; 1533-4287
• DOI: 10.1519/00124278-200508000-00008

The purpose of the present study was to examine the influence of 3 different high-intensity interval training regimens on the first and second ventilatory thresholds (VT1 and VT2), anaerobic capacity (ANC), and plasma volume (PV) in well-trained endurance cyclists. Before and after 2 and 4 weeks of training, 38 well-trained cyclists (VO2peak = 64.5 ± 5.2 ml·kg·min) performed (a) a progressive cycle test to measure VO2peak, peak power output (PPO), VT1, and VT2; (b) a time to exhaustion test (Tmax) at their VO2peak power output (Pmax); and (c) a 40-km time-trial (TT40). Subjects were assigned to 1 of 4 training groups (group 1n = 8, 8 3 60% Tmax at Pmax, 1:2 work-recovery ratio; group 2n = 9, 8 × 60% Tmax at Pmax, recovery at 65% maximum heart rate; group 3n = 10, 12 × 30 seconds at 175% PPO, 4.5-minute recovery; control groupn = 11). The TT40 performance, VO2peak, VT1,VT2, and ANC were all significantly increased in groups 1, 2, and 3 (p < 0.05) but not in the control group. However, PV did not change in response to the 4-week training program. Changes in TT40 performance were modestly related to the changes in VO2peak, VT1, VT2, and ANC (r = 0.41, 0.34, 0.42, and 0.40, respectively; all p < 0.05). In conclusion, the improvements in TT40 performance were related to significant increases in VO2peak, VT1,VT2, and ANC but were not accompanied by significant changes in PV. Thus, peripheral adaptations rather than central adaptations are likely responsible for the improved performances witnessed in well-trained endurance athletes following various forms of high-intensity interval training programs.