Author Identifiers

ORCID: 0000-0003-2060-5616

Date of Award

2018

Degree Type

Thesis

Degree Name

Doctor of Philosophy

School

School of Medical and Health Sciences

First Advisor

Professor Kazunori Nosaka

Second Advisor

Associate Professor Chris Abbiss

Field of Research Code

110602, 110299, 119999

Abstract

Eccentric cycling training has been prescribed in continuous and low intensities protocols, based on concentric cycling parameters. While the lower metabolic demand of eccentric than concentric cycling is advantageous for clinical or ‘at-risk’ populations, it is a disadvantage for cardiovascular and pulmonary adaptations. High-intensity interval protocols may increase both, strength and endurance. Thus, this research project compared i) an incremental concentric and eccentric cycling test until exhaustion for the relationship between power output and physiological parameters <Study1>; ii) interval and continuous eccentric cycling protocols for oxygen consumption, perceived exertion and enjoyment <Study 2>; and iii) aerobic performance, muscle morphology and function after 8-week interval eccentric versus concentric cycling training <Study 3>. Study 1: Nine men and two women (20-48 y) performed an incremental concentric and eccentric cycling test. Peak power output (PPO) was 53% greater (P<0.001) for eccentric (449 ± 115 W) than concentric cycling (294 ± 61 W), and peak oxygen consumption was 43% lower (P<0.001) for eccentric (30.6 ± 5.6 ml.kg.min-1) than concentric (43.9 ± 6.9 ml.kg.min-1), but maximal heart rate was similar between eccentric (175 ± 20 bpm) and concentric cycling (182 ± 13 bpm). For training prescription, concentric PPO could be an alternative reference parameters to heart rate, but optimally eccentric PPO should be used. Study 2: The same subjects as those of Study 1 performed continuous cycling at 60% of PPO for 20 min at 60 rpm, and 13.2 min at 90 rpm (CONT13@60%), 4 x 4 min intervals at 75% of PPO with 2 min rest, 12 x 1 min at 100% of PPO with 1 min rest and 10 x 1 min at 150% of PPO with 1 min rest (INT1x10@150%). Total VO2 was the largest (p<0.0001) during INT1x10@150% (382 ± 73 ml.kg-1) and smallest (p<0.0001) during CONT13@60% (146 ± 27 ml.kg-1). The interval protocols resulted in greater VO2 (P<0.0001) than continuous protocols, and thus interval eccentric cycling could increase mechanical and metabolic load more than continuous eccentric cycling. Study 3: Eighteen men (19-56 y) performed either eccentric (EC, n=9) or concentric cycling (CC, n=8) twice a week for 8 weeks on an isokinetic cycling ergometer. Intensity was matched for perceived effort, started at 30% and 45%, and increased to 36% and 70% of concentric sprint PPO (10s) for CC and EC, respectively, and progressively increased from 5 x 2 min with a 1-min rest to 7 x 2 min with 30-s rest. The magnitude of increases in quadriceps cross-sectional area, concentric sprint PPO, countermovement and squat jump was greater (P<0.05) for EC than CC, while there were no significant differences for VO2peak, incremental concentric PPO, 6-min walking distance and maximal isometric knee extension strength. It appears that interval eccentric cycling can increase strength and endurance simultaneously. The three studies have highlighted parameters and procedures for eccentric cycling training prescription, and metabolic advantages of high-intensity interval protocols. Interval eccentric cycling training with a progressive periodisation of intensity and volume increased strength, power, and oxygen consumption, which should be considered in future application of eccentric cycling.

Available for download on Friday, July 26, 2019

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