Abstract
Objective: This study aimed to analyse the changes in the biomechanical and psychophysiological responses, and the body mass of trailers in a small-distance (44 km and 1520 m elevation gain) trail competition performed in tropical conditions. Methods: Ten trained trailers (8 men, 2 females; age: 42.0 ± 5 years, body mass: 65.57 ± 5.4 kg, height: 174.9 ± 5.9 cm BMI: 21.71 ± 2.1, Maximal Aerobic Speed (MAS): 16.6 ± 2.1 km·h-1) volunteered to take part in the competition, comprising eight laps of 5.5 km. At the end of each lap, the trailers had to stop for 10 min to perform tests measuring 1) the maximal horizontal force (F0), theoretical maximal running velocity (V0) and maximal power output (PO) during a 30-m sprint; 2) the vertical oscillations and maximal relative force during a 30-s treadmill submaximal run; 3) the perceived exertion and pleasure; and 4) body mass. The pacing, stride variations and heart rate were continuously recorded during the race. Results: The variations of PO (W·kg-1) during the 30-m sprint and perceived pleasure were significant (p = 0.003 and p = 0.02, respectively) influencing factors of pacing. A significant decrease (p the first and last laps. Fraction of MAS and MAS were significantly (p = 0.004 and p = 0.04, respectively) related to the trail performance. Conclusions: Training programmes could be proposed that include the increase of MAS, fraction of MAS and lower limb PO. During the competition, it could be interesting to plan a drinking programme to avoid potential thermoregulatory impairment, as well as psychological strategies to increase pleasure.
Highlights
Trail running races, which are competitions in a natural environment with minimal paved or asphalt road, are becoming one of the most popular disciplines in endurance running (Hoffman & Wegelin, 2009)
Between the different laps (Figure 2 and Figure 3, Table 3), the one-way analysis of variance (ANOVA) revealed a significant increase in the mean pacing (F = 13.18, p < 0.0001), perceived exertion (F = 25.34, p < 0.0001), affective load (F = 14.36, p < 0.0001) and perceived fatigue (F = 24.94, p < 0.0001) and a significant decrease in the perceived pleasure (F = 3.59; p < 0.01), mean stride frequency (F = 6.51, p < 0.005) and mean stride length (F = 7.81, p < 0.001), as well as body mass (F = 27.33, p < 0.0001, with 2.7% loss between the first and last laps)
In the 30-m sprint, we observed a significant decrease in the mean speed (F= 7.58, p < 0.0004), maximal speed (F = 7.75, p < 0.0004), POrelmax (F = 4.65, p < 0.006), POmax (F = 5.53, p < 0.002), F0rel (F = 4.23, p < 0.001), and V0 (F = 7.75, p < 0.0005)
Summary
Trail running races, which are competitions in a natural environment with minimal paved or asphalt road (not exceeding 20% of the total course), are becoming one of the most popular disciplines in endurance running (Hoffman & Wegelin, 2009). Self-pacing has a major influence on performance (Millet, 2011a). It is well known that self-pacing exercise can be regulated from a complex protective system, including both somatosensory feedback and anticipatory mechanisms that maintain homeostasis and prevent major physiological disturbance (Coquart et al, 2012; Noakes, 2012) or motivational intensity changes (Marcora, 2008). Previous studies have suggested that changes in the stride pattern (Degache et al, 2013; Morin et al, 2011), neuromuscular alterations and perceived exertion (Fourchet et al, 2012; Giandolini et al, 2016; Lopez et al, 2011) could explain these self-regulating mechanisms in trail running. To the best of our knowledge, the respective effects of these variables on pacing and performance during real trail competitions have yet to be determined
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