Muscle and Nerve

Deciphering the metabolic networks in flowers: An integrative approach

Eccentric cycling is an emerging exercise modality in which an individual resists pedals being driven towards them on a motorised recumbent cycle ergometer. The attractiveness of eccentric cycling as a training modality stems, at least in part, from its propensity to elicit greater levels of mechanical tension for a lower metabolic cost compared to predominantly concentric or isometric training modalities. The aim of this thesis was to systematically investigate the neuromuscular responses and application to athletic performance of a bespoke eccentric cycling instrument. Study 1 assessed the reproducibility of torque, power, and muscle activation during maximal eccentric cycling over a range of cadences. This study demonstrated that at least one familiarisation session should be employed to account for the initial learning effect, although, generally poor between-session reliability was observed. A cadence of 60 rpm displayed the greatest reliability thus highlighting it as a preferential choice for use in future work. Study 2 compared the mechanical stress of, and muscle activation responses to, maximal eccentric and concentric cycling over a range of cadences. Eccentric cycling elicited up to 2.1 times greater torque and power compared to concentric cycling. Additionally, markers of technique e.g. pedal angle of peak muscle activation, and peak torque, also varied between modalities. Study 3 compared the immediate and delayed (up to 72 h post) responses to work-matched interval and continuous eccentric cycling. Decrements in muscle function (31% vs. 18%), and recovery time (48 vs. 24 hrs) were greater after the interval session; a finding attributed to greater peak mechanical tension. This greater mechanical potency of interval eccentric cycling provided rationale for its use over a longer period of training. In study 4 (a pilot study) the effects of an 8-week interval eccentric cycling intervention was examined in well trained distance runners. There was a limited effect on running economy, stretch shortening cycle function, and strength, however, data indicated a possible effect on eccentric strength and jump performance which warrants further investigation. Eccentric cycling does not appear to impact upon well trained athletes to the extent previously observed in untrained or physically impaired populations. Although, there is evidence in this thesis to support the potency of eccentric cycling as a mechanical training stimulus, the consequences of different session structures, and the ease at which it can be added to the training program of well-trained runners.

David Green

Papers

The Neuromuscular Responses to Eccentric Cycling and the Implications for Athletic Development