A general approach for analysis and enhancement performance in mountain biking modality

Abstract

Mountain biking (MTB) is an off-road cycling modality which is performed on a variety of unpaved terrains that normally include natural and/or artificial obstacles, such as trails in forests, rock garden and mud, involving successive uphill and downhill sections. Cross-country (XC) is the most popular competition format in MTB, which is composed by eight events, being Olympic cross-country (XCO) the best known among them. In addition to XCO, other XC events have gained popularity, but there are few studies on the topic. The cross-country mountain biking (XC-MTB) regulations and bicycles have been changed along the years, generating debates and uncertainties among cyclists. In this sense, the general aim of this thesis was to provide an up-todate overview of the topic, and to contribute to the advancement of knowledge on the XC-MTB events. For this, four studies were developed. Study one is a literature review that presents and discusses the most relevant scientific evidence on the XC-MTB, focusing on the characteristics of the main XC events and cyclists, as well as the development of bicycles, accidents and injuries in this sport. Evidence suggests that the physiological responses and mechanical demands change according to XC event. Moreover, we identified that the characteristics of cyclists differ according to the level of performance, and we highlighted the importance of pacing and the ability to perform technical sections of the circuit to be competitive in XC-MTB. Regarding bicycles, it is possibly to suggest that the bicycle equipped with 29” wheel and full suspension (frame with front and rear suspension) has the potential to achieve superior performance on XC-MTB circuits. The purpose of the study two was to investigate the pacing profile and performance level of XC cyclists on different technical and non-technical sections during a cross-country short track (XCC) event. Twenty professional cyclists (under23 and elite) performed six laps on a XCC circuit during the International MTB Cup. In general, the cyclists adopted a positive pacing profile, the same profile adopted by the elite and under-23. Faster cyclists adopted a more even pacing profile, while slower cyclists adopted a reverse J-shaped pacing profile. In addition, faster cyclists spent less time than slower cyclists during a non-technical sustained uphill section. Therefore, we conclude that superior XCC performance was associated with a more even pacing profile and a higher performance on a non-technical sustained climb section. The purpose of the study three was to evaluate mechanical parameters and pacing profile adopted by twelve professional male elite XC cyclists during XCC and XCO events in MTB World Cup. During both competitions, total time, speed, power output (PO) and cadence (CA) were recorded. While total race time was higher in XCO, speed, PO and CA were significantly higher in XCC. The pacing profile adopted by the cyclists in XCC was variable, while in XCO was positive. In addition, cyclists adopted a more conservative starting pace in XCC (below average race speed) but a more aggressive start in XCO (above average race speed). Therefore, since the parameters evaluated are different between XCC and XCO, the strategies and training methods developed to achieve superior performance must be specific to each competition format. Finally, the purpose of the study four was to assess whether body mass and body composition may be related to performance measures in XC-MTB, such as PO and time to exhaustion. Forty amateur XC cyclists were recruited to participate in this study. Anthropometric measurements were take and an incremental test on a cycle ergometer was performed. Our findings show that body mass and fat mass are associated with XC-MTB performance measures, but fat-free mass did not.