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Purpose: The aim of this study was to investigate changes in physiological and performance variables in triathletes following a four week period of reduced training volume and increased training intensity. Methods: Sixteen moderately trained triathletes were randomly allocated to two groups: a control (CON) group which followed their usual training, or a high intensity training (HIIT) group which completed two HIIT sessions per week during four weeks of reduced training volume Results: Maximal oxygen comsumption (VO2max) increased significantly in the HIIT group (p = .03, d = .5) but remained unchanged in the CON. Cycling power at first and second ventilatory threshold (PVT1 and PVT2) increased significantly in the HIIT subjects (p = .03, d = 1.0) and was unchanged in the CON participants (p = .57). During the simulated triathlon test, pre-post test cycling times and average power (Pav) were unchanged in both groups (p > .05). No significant interactive effects between groups were observed for running time (p = .50). Conclusion: After a 4-week HIIT program, VO2max and PVT1 and PVT2 were found to have increased significantly while cycling and running performance were unchanged, despite an overall reduction in training time. However, in order to improve running or cycling performances, high volume training programs are highly recommended. In the present study, performance was only shown to improve with usual (high volume) training. Abstract from author
© Copyright 2018 International Journal of Sports Physiology and Performance. All rights reserved.