Prior research has demonstrated the benefits of 3 to 8 weeks of eccentric cycle training in athletes, the elderly, and in suffers of various pathophysiological conditions. Eccentric cycling requires participants to absorb force generated by an electric motor that drives a traditional cycle crank in a reverse fashion. Relative to traditional concentric cycle training, eccentric cycling is lower in metabolic cost and facilitates greater force production through multi-joint leg actions. Chapter 2 reports on an investigation that utilises an eccentric cycling ergometer to evaluate and observe the influence of eccentric cycle training on a range of key performance parameters, and physiological measures on a well-trained cycling population. Specifically, in this novel study we assessed the physiological performance measures of leg spring stiffness, 4 s mean maximal sprint power, 4-km time-trial performance, and economy prior to, during, and following periodised eccentric cycle training. The investigation recruited eight healthy well-trained male participants (mean ± SD; age: 33 ± 12 yr; mass: 80 ± 11 kg; VO₂peak: 64 ± 8 ml.kg⁻¹.min⁻¹) to take part in a 6 week, 12 session eccentric cycling study. Utilising a commercially available eccentric ergometer (Cyclus2, Leipzig, Germany), the participants replaced two hours of their weekly cycle training, with eccentric cycling. Initial training loads were prescribed based on 25% of participant 4 s mean maximal sprint power (MM4SP). Stepwise increases of training load occurred every 3ʳᵈ training session. Assessments of submaximal hopping to evaluate leg spring stiffness, 4 s mean maximal sprint power and 4-km time-trial performance were conducted, prior-to, during the 3ʳᵈ week (Mid), and 1 and 4 weeks following the eccentric cycling intervention. Over a 6 week period, this stepwise approach led to an increase in workload from 25% to 50% of participant MM4SP. Overall participants achieved 97 ± 4% of their individual prescribed training load during the 6 week eccentric cycling training intervention. Relative to baseline measures, muscle stiffness effects were very likely positive (35.8 ± 30.4%) at week 3 (Mid), and at 1 week post (57.7 ± 22.3 and 46.6 ± 26.0%) week 4 post intervention. Effects for 4 s mean maximal sprint power were likely beneficial at 60 rpm at week 11 relative to both baseline, and week 7. Similarly, likely beneficial effects were reported at 120 (week 7 – pre), and 135 rpm (week 11 – pre). 4-km time-trial performance, at Mid (mean ± SD %: 0.2 ± 2.8%), and 1 week (0.7 ± 2.3%) post-training produced unclear alterations, while likely beneficial improvements were seen at week 4 (2.3 ± 3.6%) post-training. The findings of the current study suggest that 12 sessions of eccentric training over a 6 week period improved 4-km time-trial performance, and muscle stiffness within a well-trained population. Outcomes for the remaining endurance and sprint performance related measures however predominantly resulted as unaltered or unclear over the participant population