Resumen de Influence of High-Intensity Interval Training on Adaptations in Well-Trained Cyclists

Paul B. Laursen, Cecilia M. Shing, Jonathan M. Peake, Jeff S. Coombes, David G. Jenkins

• 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 (V O2peak 5 64.5 ± 5.2 ml·kg-1·min-1) performed (a) a progressive cycle test to measure V O2peak, peak power output (PPO), VT1, and VT2;

  (b) a time to exhaustion test (Tmax) at their V O2peak power output (Pmax); and (c) a 40-km time-trial (TT40). Subjects were assigned to 1 of 4 training groups (group 1: n = 8, 8 X 60% Tmax at Pmax, 1:2 work-recovery ratio; group 2: n = 9, 8 X 60% Tmax at Pmax, recovery at 65% maximum heart rate; group 3: n = 10, 12 X 30 seconds at 175% PPO, 4.5-minute recovery; control group:

  n = 11). The TT40 performance, V O2peak, 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 inV O2peak, 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 V O2peak, 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.