Efficiency in Cycling for Road and Triathlon Disciplines: Determinants and Insights

Abstract

Cycling is a demanding endurance sport, and a key modality during triathlon events. Cycling efficiency is determinant on cycling, which can affect performance and predict race's outcome. Therefore, the aim of this Academic dissertation, written according to the Scandinavian method, was to identify and summarize the determinants factors that impact cycling efficiency. For the identification of the studies, we searched in the electronic databases of PubMed, Scopus and Web of Science including all studies until January 2025. In addition, conducted a manual search within the reference lists of the studies selected. The selection of the studies and the data extraction followed the PRISMA 2020 guidelines. We included only randomized controlled trials (RCTs). The eligibility criteria included athletes of all levels, ages, and genders, excluding any study involving participants with a metabolic disease or who were undergoing rehabilitation. The risk of bias was assessed using the Joanna Briggs Institute critical appraisal tools for RCTs. A total of 35 studies (589 participants) were included after the screening process. There was high heterogeneity regarding age and performance level, and the risk of bias was considered high while evidence certainty was judged as low. The studies investigated different cycling efficiency variables including delta efficiency, gross efficiency, net efficiency, and work efficiency. Lower cadence positively impacts cycling efficiency whereas prolonged cycling, hypoxia and hyperoxia negatively affects cycling efficiency. Other determinants such as strength training, sprint training, supplementation and heat acclimation need further investigation to clarify their effect(s). Given the high heterogeneity and the low level of evidence, further studies are needed to better clarify the effects of the factors that influence cycling efficiency, particularly those involving experimental studies testing the impact of the abovementioned determinants.