Nils Haller

Background: Gait regularity reflects the consistency of locomotor patterns. During prolonged load carriage, such as military marches, gait patterns may change due to accumulating fatigue, pain, and environmental demands. However, the progression of gait regularity and its determinants during extended real-world walking remain insufficiently understood.Methods: This observational field study examined gait regularity during a 90 km loaded military march in Swiss cadets. Triaxial acceleration was continuously recorded from the upper arm using a Polar Verity Sense. Gait regularity was quantified using step-to-step autocorrelation of acceleration magnitude. Data were split into five consecutive 18 km segments and analyzed using repeated-measures ANOVA with Greenhouse-Geisser correction and Holm-adjusted post hoc tests. Linear mixed-effects models assessed associations of gait regularity with accumulated distance, walking speed, and terrain slope.Results: Nineteen cadets (21.4 ± 1.6 years) were included. Mean gait regularity decreased progressively across march segments. A significant effect of segment was observed (p < 0.001, = 0.669), with nine of ten significant pairwise comparisons (p < 0.05), and eight large effect sizes (|d| > 0.8). Mixed-effects analyses showed gait regularity was associated with all fixed effects (all p < 0.001). Distance and speed accounted for 32.3% of the variance in gait regularity, while terrain slope contributed only minimally.Significance: Gait regularity decreased systematically during a prolonged military march under real-world conditions. Autocorrelation-based analysis of arm-worn acceleration data captured progressive changes in locomotor patterns. These findings support wearable-based monitoring of locomotor adaptations during prolonged load carriage and future fatigue and injury risk assessment.

This systematic review with network meta-analysis aimed to identify the most effective intervention incorporating a substantial physical activity component in individuals with comorbid depressive symptoms and nonspecific chronic low back pain (LBP). A search of six databases (PubMed/Medline, PsycINFO, Web of Science Core Collection, EMBASE, CINAHL, CENTRAL) was conducted up to July 30, 2025. Randomised controlled trials on participants > 15 years with comorbid clinically relevant depressive symptoms (e.g., Beck Depression Inventory (BDI)-II > 13) and chronic (> 12 weeks) LBP were included. Interventions involved ≥ 33% active movement and lasted ≥ 2 weeks. Outcome-wise risk of bias (RoB) for the self-reported outcomes was assessed using the Cochrane RoB 2 tool. Primary outcomes were (i) changes in depressive symptoms (mandatory) and (ii) pain intensity, disability and quality of life, with each study required to include at least one of three additional outcomes. We calculated frequentist-based network meta-analysis. Of 2138 studies, five studies ( N = 834, 50.1% female, mean age: 52.8 years) with eight treatments were included. Overall RoB ranged from low to some concerns. Yoga with education was most effective at mid-term follow-up (intervention duration closest to 12 weeks, k = 9), showing improvements in pain (SMD=−1.05 [95%CI=−1.38 to −0.72]) and clinically relevant improvements in depressive symptoms (SMD=−1.48 [95%CI=−1.81 to −1.14]), all vs. usual care. Antidepressant therapy with pain self-management (e.g., physical activity, relaxation, breathing) moderately affected depressive symptoms (SMD=−0.56 [95%CI=−0.60 to −0.53]) and pain (SMD=−0.53 [95%CI=−0.56 to −0.49]). At long-term follow-up, antidepressant therapy with pain self-management, and online- and mobile-based therapy showed superiority over usual care. The overall certainty of evidence across outcomes was low to very low. With very low certainty evidence, yoga combined with education yielded the most favourable effects across outcomes. However, these findings should be interpreted with caution and require adequately powered future trials. While other approaches showed small to moderate effects, their clinical relevance remains uncertain. PROSPERO 2024 ID : CRD42024523604.

The study investigated the relationship between external and internal training load measures in 25 male elite youth soccer players (age: 16.6 ± 0.9 years, VO _2max : 59 ± 4 ml/min/kg) over 3 months. External load (i.e., total distance, high metabolic power distance, high-speed running) was quantified using a local positioning system and related to subjective (RPE, sleep quality, drive (energy level)), biochemical (creatine kinase (CK), lactate dehydrogenase (LDH), C-reactive protein (CRP), urea, cortisol, transferrin), and neuromuscular (CMJ) markers. Single day workload (1DL), exponential 7-day workload (7DL), and the acute: chronic workload ratio (ACWR) were calculated. 1DL parameters were correlated (Spearman’s rho) with RPE (range r = 0.24 to 0.43, p < 0.01) and 1DL distance was negatively related to drive ( r = − 0.28, p < 0.001). LDH correlated positively with training load across all calculation methods (up to r = 0.27, p < 0.01). CK exhibited positive correlations to ACWR training load ( r = 0.23 to 0.27, p < 0.05), while transferrin (ACWR) and CRP (1DL) showed negative associations to training load ( r = − 0.21 to − 0.28, p < 0.05). CMJ eccentric mean force was negatively correlated with all ACWR training load variables ( r = − 0.22 to − 0.25, p < 0.01). In summary, subjective measures showed stronger and more consistent associations with training load than biomarkers or neuromuscular testing. Practitioners may confidently use well-structured questionnaires for load monitoring in elite youth soccer.

Background: This study aimed to evaluate acute and chronic exercise-induced changes in cell-free DNA (cfDNA) concentrations during a 7-day high-intensity interval training (HIIT) shock microcycle in trained endurance athletes. Thirty-five participants were randomly assigned to one of three groups: a HIIT-only group (HSM), a HIIT plus low-intensity training group (HSM + LIT), and a control group maintaining regular training. The intervention included 10 HIIT sessions (5 × 4 min at 90–95% maximum heart rate) over 7 days, with HSM + LIT completing an additional 30 min of low-intensity training after each session. Physiological exercise testing (PET) was conducted at baseline, 3-, 7-, and 14-days post-intervention. On days 2 and 7 during the intervention, HIIT sessions were supervised in both morning and afternoon, and venous blood samples were collected at rest, immediately post-exercise, and 30 min post-exercise to measure cfDNA for 90 and 222 bp fragments. Correlations between cfDNA and physiological exercise variables such as peak power output (PPO), running velocity at lactate threshold (LT), and VO₂ _max were analyzed. Results: cfDNA ⁹⁰ (10.4-fold, p < 0.001) and cfDNA ²²² (12.4-fold, p < 0.001) increased significantly after PET. In addition, cfDNA ⁹⁰ (17.1-fold, p < 0.001) and cfDNA ²²² (20.2-fold, p < 0.001) increased after HIIT, both remaining significantly elevated 30 min post-HIIT (both p < 0.001). cfDNA ⁹⁰ concentrations were higher in afternoon (22.4-fold) compared to morning HIIT sessions (17.2-fold, p < 0.001). A significant interaction effect was found between group and measurement point for cfDNA ⁹⁰ ( p < 0.001) and cfDNA ²²² ( p < 0.001), with higher concentrations in HSM + LIT compared to HSM 30 min post-HIIT. cfDNA ⁹⁰ showed moderate correlations with PPO ( r = 0.48, p < 0.001), LT ( r = 0.36, p < 0.001) and VO _₂max ( r = 0.30, p = 0.01). cfDNA ²²² correlated moderately with VO _₂max ( r = 0.34, p = 0.001) and slightly with PPO ( r = 0.21, p = 0.05). No chronic changes in cfDNA were observed throughout the study period. Conclusions: cfDNA is a reliable marker for detecting acute exercise-induced stress. However, the potential of cfDNA for detecting chronic adaptations in short-term, high-intensity interval training settings, such as a HIIT shock cycle, appears limited thus far. Trial registration clinicaltrials.gov, NCT05067426. Registered 05 October 2021—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT05067426 . Graphical

Background: Patients with post–COVID-19 condition (PCC) experience persistent, long-term health consequences following SARS-CoV-2 infection, including fatigue, hyperventilation, cognitive impairment, and limitations in daily activities. There is emerging evidence suggesting that exercise and respiratory therapy–based telerehabilitation is safe and could potentially improve physical capacity while reducing health care costs. Objective: This study aims to evaluate the superiority of a multimodal, symptom-titrated telerehabilitation program over standard care in patients with PCC who are severely affected, using the highest oxygen uptake rate (VO2peak [mL/min/kg]) achieved during the cardiopulmonary exercise test (CPET) and minute ventilation/carbon dioxide production slope (VE/VCO2 [full slope]) as primary outcomes. In addition, this study seeks to provide novel insights into the clinical and physiological adaptations associated with PCC, informing future rehabilitation strategies. Methods: This prospective, randomized, waitlist-controlled trial was approved by the Rhineland-Palatinate Medical Association ethics committee. All procedures comply with the Declaration of Helsinki. This study comprises 3 examination time points, which include patient-reported outcomes, clinical assessments, and a CPET. It is structured into an 8-week intervention phase followed by an 8-week follow-up phase. Following baseline assessment, patients will be randomly assigned to either the intervention group (IG) or the control group (CG). During the intervention phase, IG participants will receive a web-based, multimodal, symptom-titrated telerehabilitation program consisting of sports medicine consultations, weekly teleconsultations, a structured pacing approach, and exercise and respiratory therapy. In contrast, CG participants will receive treatment as usual, which includes a single sports medicine consultation on healthy habits and a self-directed pacing approach for managing symptoms and daily activities. During the follow-up phase, IG participants will continue training independently without teleconsultations, whereas CG participants will undergo the same telerehabilitation intervention as the IG. A follow-up assessment will be conducted for both groups to evaluate long-term effects. This study adheres to the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) guidelines and follows the Consensus on Exercise Reporting Template. Results: Recruitment began in August 2023 and was extended until March 2025. As of March 2025, 80 participants have been recruited, and data analysis is ongoing. Final results are expected by December 2025, with a cross-sectional analysis of baseline data anticipated by July 2025. Conclusions: This study is the first randomized controlled trial investigating the effectiveness of multimodal and symptom-titrated telerehabilitation in patients with PCC who are severely affected. The integration of various objective diagnostic systems will provide valuable insights into emerging postviral fatigue syndromes, supporting the development of CPET-based diagnostics, personalized rehabilitation strategies, and future research on long-term telerehabilitation effectiveness. The findings will be disseminated through peer-reviewed publications, professional networks, and patient advocacy groups to ensure scientific, clinical, and public impact. Trial Registration: German Clinical Trials Register (DRKS) DRKS00032394; https://drks.de/search/de/trial/DRKS00032394 International Registered Report Identifier (IRRID): DERR1-10.2196/65044