Background: Adventure race (AR) is an ultra-prolonged sport performed in an intense interaction with different nature environments, which has experienced significant growth in later
years. It is composed of multiple sports disciplines, demanding a good physical conditioning linked to a large cognitive component, and totaling from 3-24 hours (sprint races) to 1-10 days (expedition
races). According previous studies involving similar ultra-endurance events, it is plausible to believe that a certain degree of rhabdomyolysis exists during an AR, which could lead to increases in
muscle soreness and consumption of non-steroidal anti-inflammatory drugs (NSAID). However, to our knowledge, these conditions were not previously assessed in the literature during an adventure sprint
race. Thus, the aims of this study were to verify myoglobin plasma levels (a rhabdomyolysis marker), the level of perceived pain and NSAID usage following an adventure sprint race.
Methods: Sixteen athletes (39.4±1.6 years old; 169.9 ± 1.5 cm of height; 70.4 ± 2.5 kg of body weight; 24.4 ± 0.7 kg/m2 of body mass index; 3,219 ± 358 METs of score in the
International Physical Activity Questionnaire) from eight teams (05 female, 11 male) were volunteers of this investigation. They performed an official 35-km adventure race in Minas Gerais
State/Brazil, composed of mountain bike, trekking, water trekking, orienteering and rappelling disciplines. Blood samples were collected for analysis of myoglobin levels (Architect-Abbott) and
athletes were asked to rate their level of muscle soreness at pre- and post-race moments. Muscle soreness was evaluated by a Visual Analogic Scale (i.e., a 10 cm-long axis ranging from 0 to 10, where
0 means “no pain” and 10 means “unbearable pain”) when the thigh were palpated during knee flexion and extension conditions. Moreover, athletes were asked about their NSAID use at post-race moment.
Comparison of myoglobin levels at pre and post-race moments was verified to Wilcoxon test. Data are reported as mean ± SEM. Statistical significance was set at P<0.05 (Statistic 7.0, Statsoft, USA).
Results: The subjects completed the race in 9.5 ± 0.2 h (3.7± 0.1 km/h of average velocity). Plasma concentrations of myoglobin were within the reference range for all athletes at
pre-race moment and presented a pronounced and significant increase (2,755± 125 %; P<0.05) after the race. Muscle soreness rose from “no pain” to “mild pain” from pre- to post-race moments, and no
consumption of NSAID was reported by all the volunteers. Furthermore, none of the athletes experienced an adverse medical event requiring medical attention during or after the race.
Conclusions: We concluded that rhabdomyolysis with myoglobinemia was similar, whereas muscle soreness and NSAID usage were lower in athletes following a 35-km adventure sprint race
than those found in previous studies involving adventure expedition race and triathlon competitions. When considering these data together, we could argue that adventure sprint race can induce
exertional rhabdomyolysis, which remains asymptomatic and not related to medicine use often observed in ultraendurance athletes.