European journal of sport science最新文献

Individuals are recommended to lead active lifestyles throughout the life course. The model of physical activity-related health competence (PAHCO) adopts a competence approach by integrating physical, cognitive, and motivational determinants for health-enhancing PA (movement competence, control competence, self-regulation competence). Drawing on a comprehensive dataset pooling, the goal of the present study was to model the idiosyncratic courses of 10 PAHCO indicators over the life span. We identified studies that empirically operationalized PAHCO, combining data of 7134 individuals (age range: 15–97 years; 61% female) from 18 different populations (prevention and rehabilitation sectors). We applied a stepwise multilevel analysis approach with disjunct sub-samples (n = 48) to examine linear and quadratic associations between age and PAHCO. Indicators of movement competence (i.e., manageability of endurance, strength, and balance demands; task-specific self-efficacy) congruently showed negative associations with age (0.054 ≤ $$ ≤ 0.211). However, parameters of control competence remained stable across the life span (−0.066 ≤ β ≤ 0.028). The three indicators of self-regulation competence revealed an inconsistent relationship with age, though uncovering positive associations for self-control (β = 0.106) and emotional attitude toward PA (β = 0.088). The associations of some indicators varied significantly across sub-samples. The results suggest differential analyses for associations between PAHCO and age. While the physically determined PAHCO indicators (movement competence) probably decline across the life span, the ability to ensure regularity of PA (self-regulation competence) or align PAs with an individual's health (control competence) appear to remain constant or improve with increasing age. The findings reinforce a de-stigmatizing approach for PA promotion practices with considerable space for aligning activities with health also in the elderly.

Blood flow restriction (BFR) is increasingly being used to enhance aerobic performance in endurance athletes. This study examined physiological responses to BFR applied in recovery phases within a high-intensity interval training (HIIT) session in trained cyclists. Eleven competitive road cyclists (mean ± SD, age: 28 ± 7 years, body mass: 69 ± 6 kg, peak oxygen uptake: 65 ± 9 mL · kg⁻¹ · min⁻¹) completed two randomised crossover conditions: HIIT with (BFR) and without (CON) BFR applied during recovery phases. HIIT consisted of six 30-s cycling bouts at an intensity equivalent to 85% of maximal 30-s power (523 ± 93 W), interspersed with 4.5-min recovery. BFR (200 mmHg, 12 cm cuff width) was applied for 2-min in the early recovery phase between each interval. Pulmonary gas exchange (V̇O₂, V̇CO₂, and V̇E), tissue oxygen saturation index (TSI), heart rate (HR), and serum vascular endothelial growth factor concentration (VEGF) were measured. Compared to CON, BFR increased V̇CO₂ and V̇E during work bouts (both p < 0.05, dz < 0.5), but there was no effect on V̇O₂, TSI, or HR (p > 0.05). In early recovery, BFR decreased TSI, V̇O₂, V̇CO₂, and V̇E (all p < 0.05, dz > 0.8) versus CON, with no change in HR (p > 0.05). In late recovery, when BFR was released, V̇O₂, V̇CO₂, V̇E, and HR increased, but TSI decreased versus CON (all p < 0.05, dz > 0.8). There was a greater increase in VEGF at 3-h post-exercise in BFR compared to CON (p < 0.05, dz > 0.8). Incorporating BFR into HIIT recovery phases altered physiological responses compared to exercise alone.

To investigate the effect of forced even pacing through virtual pacing assistance and an opponent in a competitive setting on end-spurt behaviour in freestyle swimmers, including related physiological underpinnings. Twenty-seven competitive swimmers and triathletes were recruited. There were four 1500 m freestyle trials: (i) familiarisation time trial, (ii) self-paced time trial (STT), (iii) head-to-head competition time trial (CTT) and (iv) forced even pacing through virtual pacing assistance time trial (FET). Eventually, 12 swimmers met the criteria for the CTT and FET to be included in the analysis. Changes in end-spurt behaviour, finishing time and physiological parameters (lactate, cortisol, noradrenaline and heart rate) were analysed using a linear mixed model with fixed effects for trials and a random effect for swimmer identity. A separate linear model was computed for competition outcome. The end-spurt for each race was determined by means of an end-spurt indicator (ESI; ESI > 0 greater end-spurt). Swimmers demonstrated a significantly greater ESI in FET (+2.6; p < 0.001) and CTT (+1.4; p = 0.022) compared to STT. Blood lactate concentration in FET (+1.0 mmol L⁻¹; p < 0.001) and CTT (+1.6 mmol L⁻¹; p < 0.001) was significantly higher than in STT. Winners had a significantly greater ESI than losers in CTT (+1.6 and p = 0.005). Swimmers utilised a greater end-spurt through metabolically optimal forced even pacing by virtual pacing assistance and in a head-to-head competition due a larger mobilisation of anaerobic reserves as indicated by greater blood lactate concentrations. Winners had a significantly greater end-spurt than losers despite similar metabolic disturbances.

The purpose of this study was to clarify the temporal coordination between gaze, head, and arm movements during forehand rallies in table tennis. Collegiate male table tennis players (n = 7) conducted forehand rallies at a constant tempo (100, 120, and 150 bpm) using a metronome. In each tempo condition, participants performed 30 strokes (a total of 90 strokes). Gaze, head, and dominant arm (shoulder, elbow, and wrist) movements were recorded with an eye-tracking device equipped with a Gyro sensor and a 3-D motion capture system. The results showed that the effect of head movements relative to gaze movements was significantly higher than that of eye movements in the three tempo conditions. Our results indicate that head movements are closely associated with gaze movements during rallies. Furthermore, cross-correlation coefficients (CCs) between head and arm movements were more than 0.96 (maximum coefficient: 0.99). In addition, head and arm movements were synchronized during rallies. Finally, CCs between gaze and arm movements were more than 0.74 (maximum coefficient: 0.99), indicating that gaze movements are temporally coordinated with arm movements. Taken together, head movements could play important roles not only in gaze tracking but also in the temporal coordination with arm movements during table tennis forehand rallies.

This study examined the impact of continuous blood flow restriction (BFR) during repeated-sprint exercise (RSE) on acute performance, peripheral, systemic physiological, and perceptual responses. In a randomized crossover design, 26 adult male semi-professional and amateur team-sport players completed two RSE sessions (3 sets of 5 × 5-s sprints with 25 s of passive recovery and 3 min of rest) with continuous BFR (45% arterial occlusion; excluding during between-set rest periods) or without (non-BFR). Mean and peak power output were significantly lower (p < 0.001) during BFR compared to non-BFR (d_z = 0.85 and 0.77, respectively). Minimum tissue saturation index during the sprints and rest periods was significantly reduced (p < 0.001) for BFR (d_z = 1.26 and 1.21, respectively). Electromyography root mean square was significantly decreased (p < 0.01) for biceps femoris and lateral gastrocnemius muscles during BFR (d_z = 0.35 and 0.79, respectively), but remained unchanged for the vastus lateralis muscle in both conditions. Oxygen consumption and minute ventilation were significantly reduced (both p < 0.01) for BFR (d_z = 1.46 and 0.43, respectively). Perceived limb discomfort was significantly higher (p < 0.001) for BFR (d_z = 0.78). No differences (p > 0.05) in blood lactate concentration or rating of perceived exertion were observed between conditions. Blood flow-restricted RSE reduced performance and likely increased the physiological and perceptual stimulus for the periphery with greater reliance on anaerobic glycolysis, despite comparable or decreased systemic demands.

We investigated the effect of ischemic preconditioning (IPC) with and without caffeine supplementation on mean power output (MPO) during a 4-min cycling time-trial (TT). In a double-blinded, randomized, crossover-design, 11 trained men performed a TT on 4 days separated by ∼1 week. One hour before TT, participants ingested either caffeine (3 mg kg bw⁻¹) or placebo pills, after which femoral blood-flow was either restricted with occlusion cuffs inflated to ∼180 mmHg (IPC), or sham-restricted (0–10 mmHg; Sham) during 3 × 2-min low-intensity cycling (10% of incremental peak power output). Then, participants performed a standardized warm-up followed by the TT. Plasma lactate and K⁺ concentrations and ratings of perceived exertion (RPE) were measured throughout trials. TT MPO was 382 ± 17 W in Placebo + Sham and not different from Placebo + IPC (−1 W; 95% CI: −9 to 7; p = 0.848; d: 0.06), whereas MPO was higher with Caffeine + Sham (+6W; 95% CI: −2 to 14; p = 0.115; d: 0.49) and Caffeine + IPC (+8 W; 95% CI: 2–13; p = 0.019; d: 0.79) versus Placebo + Sham. MPO differences were attributed to caffeine (caffeine main-effect: +7 W; 95% CI: 2–13; p = 0.015; d: 0.54. IPC main-effect: 0 W; 95% CI: −6 to 7; p = 0.891; d: 0.03; caffeine × IPC interaction-effect: p = 0.580; d: 0.17). TT RPE and plasma variables were not different between treatments. In conlcusion, IPC with co-ingestion of placebo does not improve short-term high-intensity performance in trained men versus a double-placebo control (Placebo + Sham) and does not additively enhance performance with caffeine. These data do not support IPC as a useful strategy for athletes prior to competition but confirms caffeine's performance-enhancing effect.

We investigated the associations of low handgrip strength (HGS, i.e., a marker of muscular fitness) with liver fat content (LFC) and serum liver enzymes in a population-based setting. We used data from 2700 participants (51.7% women), aged 21–90 years, from two independent cohorts of the population-based Study of Health in Pomerania (SHIP-START-2 and SHIP-TREND-0). Cross-sectional, multivariable adjusted regression models were performed to examine the associations of HGS with LFC, measured by magnetic resonance imaging and serum liver enzymes. We found significant inverse associations of HGS with both LFC and serum liver enzymes. Specifically, a 10-kg lower HGS was associated with a 0.59% (95% confidence interval [CI]: 0.24–0.94; p = 0.001) higher LFC, a 0.051 µkatal/L (95% CI: 0.005–0.097; p = 0.031) higher gamma-glutamyltransferase (GGT) concentration and a 0.010 µkatal/L (95% CI: 0.001–0.020; p = 0.023) higher aspartate aminotransferase (AST) concentration. The adjusted odds-ratio for prevalent hepatic steatosis (defined by a MRI-PDFF ≥5.1%) per 10-kg lower HGS was 1.21 (95% CI: 1.04–1.40; p = 0.014). When considering only obese individuals, those with low HGS had a 1.58% (95% CI: 0.18–2.98; p = 0.027) higher mean LFC and higher chance of prevalent hepatic steatosis (adjusted OR 1.74, 95% CI: 1.15–2.62; p = 0.009) compared to individuals with high HGS. We found similar associations in individuals with overweight, but not in those with normal weight. Lower HGS was strongly associated with both higher LFC and higher serum GGT and AST concentrations. Future studies might clarify whether these findings reflect adverse effects of a sedentary lifestyle or aging on the liver.

The aim of our study was to compare the effects of two different plyometric training programs (targeting knee extensors or plantar flexors) on jump height and strength of leg muscles. Twenty-nine male basketball players were assigned to the knee-flexed (KF), knee-extended (KE), or control groups. In addition to regular training, the KF group performed plyometric jumps (10 sets of 10 jumps, 3 sessions/week, 4 weeks) from 50 cm boxes with the knee flexed (90°–120°), whereas the KE group performed the jumps from 30 cm boxes with the knee much more extended (130°–170°). Jumping ability was evaluated with squat jumps (SJs), countermovement jumps (CMJs), and drop jumps from 20 cm (DJ₂₀) and 40 cm (DJ₄₀). Knee and ankle muscles were assessed during maximal isokinetic and isometric tests, and EMG activity was recorded from vastus lateralis and medial gastrocnemius. The KF group increased SJ (+10%, d = 0.86) and CMJ (+11%, d = 0.70) but decreased DJ₄₀ height (−7%, d = −0.40). Conversely, the KE group increased DJ₂₀ (+10%, d = 0.74) and DJ₄₀ (+12%, d = 0.77) but decreased SJ height (−4%, d = −0.23). The reactivity index during DJs increased (+10% for DJ₂₀, d = 0.47; +20% for DJ₄₀, d = 0.91) for the KE group but decreased (−10%, d = −0.48) for the KF group during DJ₄₀. Plantar flexor strength increased for the KE group (d = 0.72–1.00) but not for the KF group. Negative transfer across jumps is consistent with the principle of training specificity. Basketball players interested to perform fast rebounds in their training should avoid plyometric jumps with large knee flexions and long contact times.

Lower extremity injuries are prevalent in military trainees, especially in female and older trainees. Modifiable factors that lead to higher injury risk in these subgroups are not clear. The purpose of this study was to identify whether external loading variables during military-relevant tasks differ by age and sex in U.S. Army trainees. Data was collected on 915 trainees in the first week of Basic Combat Training. Participants performed running and ruck marching (walking with 18.1 kg pack) on a treadmill, as well as double-/single-leg drop landings. Variables included: vertical force loading rates, vertical stiffness, first peak vertical forces, peak vertical and resultant tibial accelerations. Comparisons were made between sexes and age groups (young, ≤19 years; middle, 20–24 years; older, ≥25 years). Significant main effects of sex were found, with females showing higher vertical loading rates during ruck marching, and peak tibial accelerations during running and ruck marching (p ≤ 0.03). Males showed higher vertical stiffness during running and peak vertical tibial accelerations during drop landings (p < 0.01). A main effect of age was found for vertical loading rates during running (p = 0.03), however no significant pairwise differences were found between age groups. These findings suggest that higher external loading may contribute to higher overall injury rates in female trainees. Further, higher stiffness during running may contribute to specific injuries, such as Achilles Tendinopathy, that are more prevalent in males. The lack of differences between age groups suggests that other factors contribute more to higher injury rates in older trainees.