European Journal of Applied Physiology最新文献

Purpose: This study aims to explore the impact of ground gradient on gait variability.

Methods: Ten healthy adults (39.3 ± 4.14 years) performed overground walking under three gradient conditions: uphill 10.1° (17.81%), - 10.1° downhill (- 17.81%), and level 0.54° (0.95%). Gait kinematics were recorded using inertial measurement units, and stride time intervals were evaluated for variability magnitude and temporal structure via Coefficient of Variation (CV) and Detrended Fluctuation Analysis (DFA-α). Heart rate was recorded and served as a measure of exertion.

Results: Significant differences in both CV and DFA-α emerged among conditions (p < 0.001). Downhill walking exhibited the highest CV (4.67 ± 1.65%) and the lowest DFA-α (0.62 ± 0.13). In contrast, uphill walking showed intermediate values (CV: 3.67 ± 0.84%; DFA-α: 0.76 ± 0.09), while level walking displayed the lowest CV (1.98 ± 0.62%) and the highest DFA-α (0.84 ± 0.1), demonstrating a parabolic effect of ground gradient with gait variability for both CV and DFA-α. Downhill walking also elicited faster average velocities (1.57 ± 0.14 m/s) compared to uphill (1.38 ± 0.09 m/s) and level (1.46 ± 0.08 m/s) walking.

Conclusion: Interestingly, while uphill walking resulted in the highest heart rate (141.9 ± 13.8 bpm), DFA-α values of stride time intervals time series did not differ significantly from level walking, suggesting that metabolic effort may not be associated with the temporal structure of gait variability. Overall, it appears that during downhill walking, pronounced neuro-mechanical demands, likely imposed by eccentric effort, affect the amount and temporal structure of variability.

The present study aimed to investigate which of two commonly performed running interval sessions elicited the greatest magnitude of and time spent with elevated muscle deoxygenation in trained middle-distance runners. Thirteen trained middle-distance runners (22.4 ± 3.2 y; 63.1 ± 10.9 kg; n = 9 males) participated in the study. Subjects completed a field-based incremental running test and two interval sessions. The interval sessions comprised a 6 × 1 km and a 15 × 400 m interval session, both with 1 min passive recovery periods. Both sessions were implemented with the aim of achieving the maximal sustainable pace for each repetition, while mean speed, heart rate, RPE, blood lactate concentration and muscle deoxygenation responses were monitored. Mean speed during the interval repetitions was significantly higher during the 400 m intervals (~ 5.63 ± 0.35 m·s^-1 vs ~ 5.30 ± 0.28 m·s^-1; p < 0.001). Both the peak magnitude of muscle deoxygenation (absolute difference ± CI 3.42 ± 2.23%; p = 0.006) and the time spent with values > 60% peak muscle deoxygenation (83.5 ± 66.4 s; p = 0.02) were significantly greater during the 400 m intervals, while the time spent with a heart rate > 90% peak heart rate was significantly longer during the 1 km interval session (570 ± 143, p < 0.001). Despite this, there was no difference in RPE, blood lactate concentration or peak heart rate between sessions. These findings suggest that 1 km intervals may preferentially target central physiologic responses while 400 m intervals may elicit greater peripheral physiological responses in trained middle-distance runners.

The integration of Large Language Models (LLMs) into scientific writing presents significant opportunities for scholars but also risks, including misinformation and plagiarism. A new body of literature is shaping to verify the capability of LLMs to execute the complex tasks that are inherent to academic publishing. In this context this study was driven by the need to critically assess LLM's out-of-the-box performance in generating evidence synthesis reviews. To this end, the signature topic of the authors' group, cross-education of voluntary force, was chosen as a model. We prompted a popular LLM (Gemini 2.5 Pro, Deep Research enabled) to generate a scoping review on the neural mechanisms underpinning cross-education. The resulting unedited manuscript was submitted for formal peer-review to four leading subject-matter experts. Their qualitative feedback on manuscript's structure, content, and integrity was collated and analyzed. Peer-reviewers identified critical failures at fundamental stages of the review process. The LLM failed to: (1) identify specific research questions; (2) adhere to established methodological frameworks; (3) implement trustworthy search strategies; (4) objectively synthesize data. Importantly, the Results section was deemed interpretative rather than descriptive. Referencing was agreed as the worst issue being inaccurate, biased toward open-access sources (84%), and containing instances of plagiarism. The LLM also failed to hierarchize evidence, presenting minor or underexplored findings as established evidence. The LLM generated a non-systematic, poorly structured, and unreliable narrative review. These findings suggest that the selected LLM is incapable of autonomously performing scientific synthesis and requires massive human supervision to correct the observed issues.

Purpose: Biological sex and muscle fiber type affect muscle relaxation. However, assessments probing the interaction effect are lacking. This study examined whether any difference in transcranial magnetic stimulation (TMS)-induced muscle relaxation results from the interaction effects of biological sex and skeletal muscle fiber properties in (un)fatigued knee extensors.

Methods: TMS-induced muscle relaxation was assessed in twenty participants (10 females/10 males) before, after a 2-min sustained maximum voluntary isometric contraction, and four times within 8-min of recovery. Vastus lateralis muscle tissue was obtained separately from the participants' dominant limb.

Results: Type I fiber distribution was not different between sexes (females: 53 ± 11%; males: 43 ± 9%; P = 0.050), and relative cross-sectional area of type I fibers was larger for females (53 ± 3% vs. 48 ± 4%; P = 0.005). Females exhibited ~ 40% slower muscle relaxation in an unfatigued state (-8.8 ± 2.3 s^- 1 vs. -12.4 ± 1.9 s^- 1; P < 0.001), and ~ 21% smaller relative decline with fatigue (females: 69 ± 26% of pre-exercise; males: 48 ± 14% of pre-exercise; P = 0.013). The relative slowing of muscle relaxation with fatigue remained lower in females through 8 min post-exercise (females: 125 ± 26% of pre-exercise; males: 101 ± 8% of pre-exercise; P = 0.009). Only in females was the relative cross-sectional area of type I fibers correlated with muscle relaxation at baseline (r = 0.82, adjusted P = 0.018), fatigue index (r = 0.78, adjusted P = 0.032), and recovery index (r = 0.89, adjusted P = 0.007).

Conclusions: Among females, muscle fiber characteristics were associated with TMS-induced muscle relaxation, whereas no comparable associations were observed in males. This underscores the importance of considering biological sex and skeletal muscle fiber properties when assessing changes in muscle relaxation responses to exercise.

This study evaluated the effects of lymphatic drainage (LD) and intense sports massage (IM) on muscle recovery after eccentric quadriceps exercise in combat sports athletes. Thirty-six athletes (24 men, 12 women; mean age 27.4 ± 4.1 years) were randomized into three groups: LD, IM, or Control. After a fatigue-inducing plyometric jump protocol, the LD and IM groups received six 30-minute recovery sessions over 72 h, while the Control group rested passively. Athletes were assessed at five time points-pre-exercise, immediately post-exercise, and a 24, 48, and 72 h-measuring perfusion (PU, Power Doppler Score), pressure pain threshold (PPT), maximal voluntary contraction (MVC), creatine kinase, C-reactive protein (CRP), and perceived recovery (TQR scale). Both IM and LD groups showed significantly greater increase in PPT at 24, 48, and 72 h compared to controls (p = 0.004-<0.001), with LD showing superior outcomes at 24 h. IM consistently increased perfusion (p < 0.001-0.026). LD also led to lower creatine kinase and CRP levels (p < 0.001-0.017). In conclusion, LD and IM enhanced muscle recovery after intense exercise, with LD showing stronger effects on pain, inflammation, and IM improving tissue perfusion.Clinical trial registration: Registered as a clinical trial under the number ISRCTN10033645.