Return-to-play (RTP) decision-making after musculoskeletal injury is increasingly recognized as a multidimensional process integrating clinical recovery, physical capacity, sport-specific performance, psychological readiness, and workload tolerance. However, current guidelines remain heterogeneous in how these domains are assessed, sequenced, and integrated into progression decisions. This narrative review synthesizes current evidence on RTP assessment and proposes a sequential multidimensional framework to address this implementation gap. The framework is based on four principles: prerequisite capacity, complementary assessment, progressive specificity, and multidomain integration. Assessments are sequenced when meaningful biological or functional dependencies exist, while psychological readiness and workload tolerance are evaluated longitudinally throughout rehabilitation. Rather than prescribing a universal test battery or clearance threshold, the framework emphasizes selecting the smallest set of valid, complementary, and non-redundant assessments needed to answer stage-specific clinical questions. Discordant findings are used to identify limiting capacities and guide reassessment rather than being reduced to a global pass/fail decision. As RTP approaches, assessment progresses toward increasingly representative sport exposure, with final clearance integrating all relevant domains, sport-specific demands, and contextual risk tolerance. The proposed framework should be considered a clinical reasoning model rather than a validated predictive algorithm. Prospective studies are required to determine whether this approach improves RTP decision-making and subsequent outcomes.
Background and Objectives: This study aimed to compare the associations of total weekly physical activity (PA) volume and time spent/day in moderate-to-vigorous PA (MVPA) with physical-functional outcomes in individuals with COPD. Methods: Patients underwent cross-sectional assessments of daily PA (7 days, measured by accelerometry), lung function, body composition, six-min walk test (6MWT), peripheral muscle strength and dyspnea. Results: Ninety-one individuals with COPD (45 men; 66 ± 8 years; FEV1 50 ± 16%predict) were studied. Both time spent/day in MVPA and total weekly PA volume were similarly associated with 6MWT, fat mass, and fat-free mass in simple correlations (0.23 < r < 0.46, p < 0.05 for all) and also in simple and multiple linear regression analyses. No significant correlations with other outcomes were found. Additionally, the correlation between total weekly PA volume and time spent/day in MVPA was strong (r = 0.78, p < 0.0001). Conclusions: In individuals with COPD, both time spent/day in MVPA and total weekly PA volume showed broadly comparable associations with physical-functional outcomes.
Background: Exercise, nutrition and environmental oxygen conditions may influence vascular function and haematological parameters. Whether repeated aerobic exercise under mild hyperbaric oxygen (HBO) during eicosapentaenoic acid (EPA) supplementation elicits different responses from the same exercise under normobaric normoxia (NN) remains unclear. Methods: Sixteen healthy young men completed an exploratory, randomised two-period crossover trial. During each 4-week period, participants cycled for 60 min at 60–70% of peak oxygen uptake twice weekly while taking EPA (2170 mg·day−1), with a 1-week washout. HBO exercise was performed at 1.41 atmospheres absolute (ATA) with 29–30% O2 and NN exercise at 1.00 ATA with 20.9% O2. Eight non-randomised EPA-only participants were included in secondary and supplementary analyses. Results: Linear mixed models showed no significant Condition effect on haematological, biochemical, or flow-mediated dilation outcomes. In the Period 1 analysis of covariance, the HBO-first group had a lower red blood cell count (4.980 vs. 5.211 × 106/µL, p = 0.035) and higher mean corpuscular haemoglobin (29.928 vs. 29.422 pg, p = 0.009) and mean corpuscular haemoglobin concentration (33.303 vs. 32.922 g/dL, p = 0.031), with no differences in haematocrit or haemoglobin. Conclusions: No consistent additional HBO effects were detected; Period 1 erythrocyte-related findings require confirmation in larger studies.
Objective: This study investigated core temperature (Tc) responses during elite Cross-Country Marathon (XCM) competitions performed under different environmental conditions and competition loads. Methods: Four elite XCM athletes (three males and one female) were monitored during three official competitions Tc was continuously recorded using a non-invasive sensor. The mean and maximal Tc (Tcmean and Tcmax), the change in Tc (ΔTc), and the time and percentage of race time spent above 38.5 °C were calculated. The competition load included Normalized Power (NP), Intensity Factor (IF), Training Stress Score (TSS), and heart rate (HR). Linear mixed models and athlete-specific z-scores were used to evaluate thermoregulatory responses. Results: Tcmax ranged from 38.5 to 39.5 °C, with inter-individual variability ranging from 3% to 94% of race time spent with a Tc above 38.5 °C. XCM2, which recorded the highest relative humidity (91%), showed the greatest thermal exposure in three of the four athletes. In the race-time, Tcmax was higher during XCM2 than XCM1 (β = −0.54 °C, p = 0.038). In the TSS, Tcmax was higher during XCM2 (β = −0.79 °C, p = 0.008) and XCM3 (β = −0.60 °C, p = 0.027) compared with XCM1. Exposure to Tc > 38.5 °C was also higher during XCM2 than XCM1 (β = −73.1%, p = 0.021). Conclusions: XCM athletes exhibited individual variability in Tcmax and time spent above 38.5 °C. These exploratory findings highlight the value of continuous Tc monitoring for characterizing individual thermoregulatory responses during competition.
Background: There is a lack of research investigating the effect of hydration status or intermuscular glycogen content on ultrasound-derived muscle quality imaging in younger adults. Purpose: To examine the effects of varied hydration and muscle glycogen status on ultrasound-measured vastus lateralis (VL) cross-sectional area (CSA) and echo intensity (EI). Materials and Methods: Thirteen young adults (Age: 23 ± 4.2 yrs; Height: 168.5 ± 6.8 cm; Weight: 76.2 ± 17.1 kg) participated in five experimental visits: (1) Baseline (regular dietary intake); (2) hypohydrated and normal carbohydrate (CHO) intake (HH-NC); (3) euhydrated and normal CHO intake (EH-NC); (4) hypohydrated and CHO restriction (HH-CR); and (5) euhydrated and CHO restriction (EH-CR) conditions. Ultrasound imaging of the right VL was used to assess CSA and EI at each visit. A two-way repeated measures ANOVA with Holm adjusted post hoc test was performed for statistical analysis. Results: Body mass was affected by both hydration and carbohydrate restriction (both p < 0.001), while Usg was greater during hypohydration (p < 0.001). VLCSA was lower following carbohydrate restriction (p = 0.010), independent of hydration status, whereas VLEI was not significantly affected by hydration, carbohydrate restriction, or their interaction (all p ≥ 0.063). Conclusions: Overall, these findings suggest that an individual’s hydration and CHO intake may influence ultrasound-derived muscle CSA assessments. Future research should continue to explore the sensitivity of EI and CSA to determine the impact of these findings in both clinical and research environments.
