ECSS Paris 2023: OP-AP12
INTRODUCTION: Backyard running is an extremely demanding ultra-endurance event where athletes strive to complete a 6.7 km lap every hour. As a ‘last man standing’ competition, the event concludes when the second-to-last participant quits, leaving the final runner to complete the ultimate lap. Remarkably, several athletes have surpassed the 100-lap mark, equivalent to an astounding 670 km. As the popularity of extreme ultra-endurance events continues to grow, understanding the physiological, psychological, and medical implications of participating in events like backyard running is paramount for safeguarding athletes’ health and promoting informed training and participation strategies. Therefore, our objective is to assess the influence of backyard running on various aspects of performance, i.e. pacing, resilience, cognitive functioning and cardiovascular responses. METHODS: Twelve male ultrarunners (38 ± 8 years old, BMI: 23.5 ± 1.6 kg/m², VO2max: 60.8 ± 4.7 ml/min/kg) participated in this study, with personal Backyards records ranging from 15 to 101 laps, covering distances between 100.5 km to 677 km. Participants were monitored during the “Backyard Ultra” event held on April 15th, 2023, in Kasterlee, Belgium. Cognitive performance was determined using a cognitive test battery COGNITION, including 8 cognitive tasks, before, during and after the event. During the event the rating of perceived exertion (RPE), lactate and heart rate (HR) were assessed. Physical performance was investigated using the total amount of completed laps and running speed per lap. Linear mixed-effects regression models were applied, and post-hoc t-tests were conducted using the Satterthwaite’s method. A significance level of p<0.050 was employed for hypothesis testing. RESULTS: Athletes completed 34 ± 17 laps equalling 227.8 ± 113.9 km with average speeds starting at 9.0 km/h and slowing down to 7.5 km/h at the end of the event. Based on the 5 training zones assessed for each participant after their cardiopulmonary exercise testing, participants ran 85.2% in zone 1 (i.e. recovery), 9.5% in zone 2 (i.e. long duration endurance), 0.1 % in zone 3 (i.e. extensive endurance), and 0.0% in zones 4 and 5 (i.e. intensive endurance and resistance, respectively). Physiological resilience (i.e. HR/speed) altered between athletes, with significantly lower values in the more proficient backyard runners at the end of the event (p<0.050). HR and lactate levels remained constant, whereas a progressive increase in RPE was noticed (p≤0.001). A significantly worsened reaction times was observed for several cognitive tasks after the event (p≤0.050), indicating reduced psychomotor speed. CONCLUSION: These observations underscore the pivotal role of cognitive performance in constraining extreme ultra-endurance running. It also suggests that implementing strategies that enhance psychomotor speed could potentially have a positive effect on one’s performance in such demanding endurance activities, including backyard running.
Read CV Kevin De PauwECSS Paris 2023: OP-AP12
INTRODUCTION: Endurance athletes are susceptible to an imbalance between training load and recovery, which can result in maladaptation, an unexplained decrement in performance and potential overtraining syndrome. In order to prevent athletes from transitioning along the continuum from being acutely fatigued towards overtraining syndrome, early detection and subsequent adjustments to the training process are imperative. Several studies have investigated the influence of training-overload protocols on various physiological responses and subjective-fatigue markers. Nevertheless, there is a need for contemporary knowledge into the comprehensive influence of training overload on physiological responses and markers of training stress commonly used in the overtraining literature. Therefore, this study aimed to investigate the influence of 2-week training overload on physiological responses and markers of training stress in endurance athletes. METHODS: Nine trained endurance athletes (distance-runners and triathletes, n=6 males; VO2max = 66.8±4.9 mL·min-1·kg-1; n=3 females, VO2max = 56.6±6.6 mL·min-1·kg-1) completed 1-week baseline training, 2-week training overload (50-70% progressive increase in training load) and 1-week recovery (30-40% reduction in training load from baseline). Immediately after each training period, physiological responses during submaximal steady-state stages and a maximal incremental time to exhaustion (TTE) test while treadmill-running were assessed, as well as subjective fatigue measures and blood biomarkers. RESULTS: No changes from baseline to after training overload were found for TTE and VO2max, although both increased after the recovery period (Δ31±24 sec and 80±75 mL·min-1, P<.05, respectively). Both maximal heart rate and blood lactate levels during the TTE test (-4±3 beats·min-1 and -1.5±1.7 mmol·L-1, P<.05), as well as heart rate and blood lactate levels at the same submaximal speed (-5±3 beats·min-1 and -0.4±0.4 mmol·L-1, P<.01), were reduced after training overload. However, these physiological responses were normalized to baseline-values following the recovery period. Subjective-fatigue markers (1-10) including perceived readiness (-2.3±1.3-point, P<.01), muscle soreness (-1.8±1.9-point, P=.02), and fatigue (-2.3±1.8-point, P<.01) were impaired after training overload but normalized to baseline-values after the recovery period. CONCLUSION: This study provides valuable insights into the comprehensive influence of training overload in endurance athletes. The present findings indicate that sports practitioners should incorporate information derived both from regular physiological tests and subjective fatigue-markers to detect maladaptive states at an early stage. *Preliminary analyses due to ongoing data collection. Data including more participants and blood biomarkers with relevance for both overtraining syndrome and relative energy-deficiency in sports will be presented.
Read CV Rune Kjøsen TalsnesECSS Paris 2023: OP-AP12
INTRODUCTION: The physiological and neuromuscular effects of uphill running training need for more evidence, to improve knowledge and a proper prescription (Barnes et al., 2013). It is well known that running at different speeds and slopes induces changes in predominantly concentric or eccentric muscle contractions, which could influence the acute and chronic responses (Lemire et al. 2008). This study aimed to compare the acute physiological and neuromuscular parameters from two-interval running sessions performed by incline and horizontal treadmill settings. METHODS: Twelve endurance-trained runners performed two incremental running tests until exhaustion (De Lucas et al. 2021), and two interval sessions composed of 10 repetitions of 1 min at maximal speed or incline that were obtained in the incremental tests (i.e. maximal aerobic workload), with recovery periods between repetitions of 1 min. VO2 and heart rate (HR) were continuously measured and averaged for each exercise interval, and for the entire session. Accordingly, the O2 pulse was calculated as the ratio of VO2/HR. Before and immediately after the 3rd, 6th, and 10th repetitions, the runners performed a countermovement jump (CMJ) to assess the neuromuscular performance. Paired t-test and ANOVA were used for analysis. RESULTS: The maximal workload obtained from the incremental tests, and then used for interval sessions were 17.5 +/- 1.0 km/h and 17.0 +/- 1.7%, respectively, for horizontal and incline tests. The mean VO2 of the entire exercise intervals was lower for horizontal than incline sessions (52.5 +/- 6.5 and 54.7 +/- 6.7 ml/kg/min; ~91% VO2max, p =0.03), while HR was significantly higher for horizontal than the uphill session (163 +/- 10 and 157 +/- 9 bpm, respectively; p =0.01). In this way, the O2 pulse was greater for uphill than the horizontal session (25.2 +/- 3.8 and 23.3 +/- 3.4 ml/beat, respectively; p <0.01). In comparison to the baseline values of CMJ height obtained before the horizontal (32.5 +/- 4.3 cm) and incline sessions (32.8 +/- 4.4 cm), there was a decrement after the 3rd repetition for both sessions (31.5 +/- 4.4 and 31.6 +/- 3.8 cm, respectively). However, there was an augment after the 6th (33.0 +/- 4.5 cm), and 10th (33.2 +/- 4.3 cm) intervals only during the horizontal interval session. During the uphill session, the CMJ values after the 6th (31.9 +/- 4.2 cm) and 10th interval (32.2 +/- 4.1 cm) was similar to the baseline. CONCLUSION: The interval sessions (10×1:1-min) performed by incline and horizontal at the maximal aerobic power can elicit different VO2 and HR responses, suggesting a greater cardiac efficiency during the uphill running. Regarding neuromuscular performance, one could observe that a more concentric running (i.e uphill) seems to induce more fatigue than horizontal (and eccentric) running during this kind of interval session. 1. Barnes, K.R., et al. Int J Sports Physiol Perform (2013) 2. Lemire, M., et al. Res Q Exerc Sport (2018) 3. De Lucas, R.D., et al. Res Sports Med (2021)
Read CV Ricardo Dantas de LucasECSS Paris 2023: OP-AP12