ECSS Paris 2023: CP-PN11
INTRODUCTION: Prolonged physical exertion, psychological stress, sleep disruption, and environmental exposures are known to affect gastrointestinal physiology and immune regulation. Recent evidence indicates that sustained high-intensity training and chronic stress can impair intestinal barrier integrity, promote dysbiosis, and contribute to systemic inflammatory responses, thereby negatively affecting recovery and performance (Lamprecht et al., 2015; Thompson, 2024). Populations exposed to persistent high operational demands, such as military special operations forces, may therefore be particularly susceptible to gut barrier dysfunction, yet data in this field remain limited. This study aimed to assess intestinal barrier status in active-duty special operations soldiers and to evaluate the effects of an eight-week gut-focused intervention on biomarkers of intestinal permeability, inflammation, and sleep quality. METHODS: A prospective, controlled study was conducted in male soldiers of the Austrian Special Forces Unit. Participants were allocated to an intervention group or a non-intervention control group. Intestinal health was assessed before and after the intervention using stool-based biomarkers, including zonulin, alpha-1-antitrypsin, calprotectin, and secretory immunoglobulin A (sIgA). The intervention consisted of daily oral zeolite supplementation combined with weekly chelation phases using oral dimercaptosuccinic acid (DMSA) and rectal calcium-EDTA. RESULTS: At baseline, a substantial proportion of participants exhibited biomarker patterns indicative of impaired intestinal barrier function. Following the intervention, the intervention group demonstrated stability or improvement of multiple gut-related biomarkers, whereas the biomarkers of the control group got worse over time. CONCLUSION: These findings suggest that a combined zeolite and chelation-based intervention is feasible in a high-performance military setting and may positively influence intestinal barrier integrity and recovery-related parameters. The results provide preliminary evidence supporting gut-targeted strategies as a component of integrated human performance optimization in special operations forces and underline the need for larger, long-term studies to confirm these effects.
Read CV Johannes PaulitschECSS Paris 2023: CP-PN11
INTRODUCTION: High-load exercise training not accompanied by adequate recovery may induce transient decline in exercise performance together with prolonged fatigue, a condition known as overreaching. Overreaching has also been linked to a broad range of physiological and psychological disturbances. However, this multidimensional phenotype has not yet been examined comprehensively within a single trial. METHODS: This preliminary analysis includes 19 participants from an ongoing RCT (target: n=45). 19 recreationally active men were randomly assigned to (i) control (CON, n=4), (ii) 8 weeks of moderate-load training with 4 supervised cycling training sessions a week (MOD, n=7), or (iii) 4 weeks of moderate-load (4 sessions/week) followed by 4 weeks of high-load (8 sessions/week) cycling training (HIGH, n=8) anticipated to induce overreaching. The study intervention is followed by a 10-day taper. Experimental assessments were conducted at baseline (T1), after 4 weeks (T2), after 8 weeks (T3), and after taper (T4). Assessments included evaluation of exercise performance (30-s sprint and 30-min time trial), maximum rate of blood lactate production (vLamax), maximal heart rate, heart rate variability (RMSSD), self-reported mood disturbances (POMS, lower score is favorable), self-reported recovery and stress (RESTQ, higher score is favorable), systemic inflammation (hsCRP), and glucose homeostasis (HOMA-IR: lower is favorable; Matsuda-index: higher is favorable). Overreaching was defined as reduced exercise performance (30-sec sprint or 30-min time trial) combined with decreased ‘Energy Index’ (POMS) between T2 and T3, with changes exceeding measurement error. Descriptive statistics (means +/- SD) with effects sizes (Cohen’s d) characterize intervention effects between T2 and T3. RESULTS: No participants in CON or MOD, but 4 participants in HIGH were classified as overreached. Mood disturbance in HIGH participants not categorized as overreached (NO, n = 4) decreased by 4 +/- 8 points (d=-0.6), whilst increased by 24 +/- 19 points (d=1.2) in HIGH participants categorized as overreached (O, n = 4). Similar trajectories were found for recovery-stress balance (NO: -21 +/- 40 points, d=-0.5; O: -54 +/- 55 points, d=-1.0), maximal heart rate (NO: +1 +/- 4 bpm, d=0.2; O: -2 +/- 1 bpm, d=-1.2), RMSSD (NO: -3 +/- 6 ms, d=-0.5; O: -39 +/- 53 ms, d=-0.7), and hsCRP (NO: +1.3 +/- 2.5 mg/L, d=0.5; O: +3 +/- 6.0 mg/L, d=0.5). Preliminary data did not suggest overreaching to impair vLamax (NO: -0.0 +/- 0.2 mmol/L/s, d=-0.18; O: -0.0 +/- 0.1 mmol/L/s, d=-0.37), HOMA-IR (NO: +0.0 +/- 0.2, d=1.6; O: -0.1 +/- 0.2, d=-1.0), or Matsuda-index (NO: -0.50 +/- 1.18, d=-1.2; O: -0.82 +/- 0.88 d=-0.1). CONCLUSION: Preliminary data of this ongoing trial indicate that overreaching may represent a complex multisystem phenomenon, but conclusions await study completion and further in-depth analyses of biosamples (blood, saliva, muscle, urine, stool) characterizing the multisystem phenotype and its underlying mediators.
Read CV Sofie EngelborghsECSS Paris 2023: CP-PN11
INTRODUCTION: Badminton performance depends on neuromuscular qualities (e.g., vertical jump capacity) and cognitive factors (e.g., rapid visual–cognitive processing). However, these parameters may be influenced by time-of-day, chronotype or genetic factors (e.g. PER3 genotype). The aim of this study was to examine the effect of time-of-day on neuromuscular and cognitive performance and to explore whether chronotype and PER3 genotype modulate these responses. METHODS: Twenty-eight competitive badminton players (19 males, 9 females) completed a randomized crossover protocol, performing a neuromuscular and cognitive test battery in the morning (08:00–09:00 h) and afternoon (17:00–18:00 h). The neuromuscular test battery included vertical jump performance (squat jump, countermovement jump, and smash jump with and without shuttlecock), change-of-direction ability (badminton footwork test), isometric handgrip strength, while cognitive battery included visual–cognitive reaction time and cognitive inhibition (via Stroop Test). Chronotype was assessed using the Horne–Östberg questionnaire, and the PER3 VNTR polymorphism was determined from saliva samples RESULTS: Compared with morning testing, several neuromuscular and cognitive variables demonstrated improved performance in the afternoon. Specifically, countermovement jump height (38.49 ± 8.04 vs. 37.35 ± 7.42 cm; p = 0.016; ES = 0.49) and smash jump without a shuttlecock (38.51 ± 11.28 vs. 37.47 ± 10.57 cm; p= 0.040; ES = 0.40) were significantly higher in the afternoon. Regarding cognitive performance visual– cognitive reaction time was also faster in the afternoon (0.365 ± 0.26 vs. 0.374 ± 0.29 ms; p = 0.029; ES = –0.43). In contrast, no time-of-day effects were observed for squat jump, smash jump with shuttlecock, the badminton footwork test or isometric handgrip strength or cognitive inhibition (p > 0.05; ES = 0.30–0.33). Additionally, neither chronotype nor PER3 genotype showed significant associations with any performance variable (p = 0.125–0.879). CONCLUSION: Badminton athletes exhibited improved performance in selected neuromuscular tasks (countermovement jump and smash jump without shuttlecock) and faster cognitive reaction time during afternoon testing, while chronotype and PER3 genotype did not influence neuromuscular or cognitive outcomes
Read CV Alvaro Lopez-SamanesECSS Paris 2023: CP-PN11