ABSTRACT Participation in triathlon may increase athletes' exposure to risk factors associated with Relative Energy Deficiency in Sport (REDs); however, effective education could enhance understanding and help mitigate risk. The views of experienced triathletes and coaches need to be considered when developing education resources aimed at improving identification and management of the syndrome. This qualitative study aimed to understand how female athletes and their coaches engaged with REDs resources, their preferences for education delivery and challenges to engaging with educational material. Twenty semi‐structured interviews were conducted with 12 female triathletes aged 25–45 years and 8 coaches aged 29–62 years. Participants included amateur (n = 8) and elite (n = 4) triathletes. Reflexive thematic analysis was utilised to construct five themes: 1. Understanding of REDs; 2. Experiences associated with REDs; 3. Engagement with educational resources; 4. Opportunities for REDs education and 5. Challenges to engaging with REDs education. Themes were mapped to the capability, opportunity, motivation‐behaviour (COM‐B) model to identify factors likely to influence engagement with a REDs education resource for female triathletes and their coaches. Both athletes and coaches voiced strong motivation to engage with REDs education and an interest in learning more about REDs. However, future engagement is likely to be influenced by the entrenched culture that encourages leanness in triathlon, and resistance to modifying training practices. Our analysis identifies the opportunity to improve female triathletes' understanding of REDs, by using podcasts that combine expert led content with lived‐experience narratives from other triathletes.
ABSTRACT This study examined the objective and perceived exercise intensity and movement volume during an acute session of a cognitive‐motor training, namely, square‐stepping exercise (SSE), in older adults under two pacing conditions and three step‐pattern complexities. Thirty older adults (73.6 ± 7.4 years) completed SSE under normal pace (Normal) and externally paced (Paced; 150% of normal walking speed) conditions in randomized order. For each condition, participants performed three different step patterns for 7‐min each: beginner, intermediate, and advanced. Exercise intensity was assessed via heart rate (HR) and rating of perceived exertion (RPE). Movement volume was assessed using accelerometry and expressed as percentage of time spent in moderate‐to‐vigorous physical activity (%MVPA) and step count (SC). Data were analyzed using repeated‐measures ANOVA (p < 0.05). Paced SSE significantly increased HR, RPE, %MVPA, and SC compared with normal (all p < 0.001). Mean HR increased from 61% to 63% of HRmax (predicted) during normal to approximately 72%–74% during the paced conditions. RPE increased from 10–11 to 13–14, whereas %MVPA increased across conditions (normal: 40%–90% and paced: 60%–87%). SC increased from 315–349 to 492–502 steps. Significant main effects of step pattern were observed for HR, RPE, and %MVPA (all p < 0.001), with a step pattern × condition interaction for %MVPA (p < 0.001). Paced SSE substantially increases cardiovascular demand and movement volume, shifting activity from light to moderate intensity in older adults. Manipulating SSE pace and step complexity is possible and may provide a practical strategy to progressively tailor SSE intensity for older adults in exercise programs.
ABSTRACT The aetiology of fatigue differs between exercise intensity domains, but limited research has explored non‐linear gait dynamics across them. To address this, this study aimed to investigate movement variability and stability in moderate, heavy, and severe intensity domains, and to examine how these dynamics evolve over time. Twenty‐one male runners performed treadmill trials at speeds corresponding to these domains, with lower limb joint angles and centre of mass displacement recorded using 3D motion analysis and analysed at the start, middle, and end of each trial. Non‐linear dynamics of joint angles and centre of mass displacement including local dynamic stability, dimensionality, and variability were assessed using Lyapunov exponent (LyE), correlation dimension (CoD), and MeanSD, respectively. Repeated‐measures ANOVAs revealed a significant effect of intensity across most parameters, including CoD and LyE at the ankle, knee, and hip (all p < 0.05), as well as MeanSD at the hip (p < 0.05). Furthermore, a significant effect of intensity was observed in 6 out of the 9 parameters measured at the centre of mass. Effects of time were sparse, with interaction effects largely confined to centre of mass variability. Post hoc analyses indicated that higher intensity domains were associated with reduced local dynamic stability, lower dimensionality, and increased variability at some sites. Changes over time were not exclusive to the severe intensity domain, suggesting that metabolic stress does not play an exclusive role in regulating movement dynamics during running. Collectively, these findings suggest that between‐domain differences in gait dynamics were more consistent with speed‐related task constraints than with cumulative fatigue or metabolic stress alone.
ABSTRACT Understanding the motivational climate is crucial for comprehending athletes' experiences in sports. We used latent profile analysis to identify subgroups of youth athletes based on their perceptions of motivational climates from coaches and peers and examined how these profiles related to enjoyment levels and intentions to continue participation. Boys and girls aged 12–14 years (N = 272, 48.5% girls) were recruited from the Norwegian youth sport context. A five‐profile solution was retained. Moreover, results showed that the profile characterized by high perceptions of a mastery climate and low perceptions of a performance climate, created by both coaches and peers, was associated with greater enjoyment than the other four profiles. Athletes in this profile also demonstrated a stronger intention to continue than those in a profile with low perceptions of a coach‐ and peer‐created mastery climate in combination with high perceptions of a coach‐ and peer‐created performance climate, as well as those in a profile with low perceptions of a coach‐ and peer‐created mastery climate. Compared with the profile with low coach‐performance perceptions, gender significantly predicted membership in the profile with low perceptions of a coach‐ and peer‐created mastery climate, combined with high perceptions of a coach‐ and peer‐created performance climate. This was the only gender difference in profile membership, indicating comparable likelihoods for boys and girls across profiles. In conclusion, profiles characterized by moderate‐to‐high perceptions of mastery climate, regardless of coach‐created performance climate levels, reported higher enjoyment than profiles with low mastery perceptions.
ABSTRACT Inter‐set blood‐flow restriction (BFR) may increase the physiological stimulus of repeated‐sprint exercise without compromising mechanical output, but evidence in trained athletes is limited. In a randomized crossover design, 26 national‐level male badminton players completed three 5 × 5‐s cycling sprints (25‐s intra‐set rest, 3.5‐min inter‐set recovery). During the first two recoveries, cuffs were inflated to 130 mmHg (BFR) or 20 mmHg (sham‐BFR). Outcomes included power output, vastus lateralis muscle oxygenation (SmO2), heart rate, exercise‐related sensations, and vertical jump. Mean and peak power declined across sets with no condition or interaction effects. Sprint decrement scores showed no differences. Muscle oxygenation kinetics revealed time and condition × time effects: recovery SmO2 was lower with BFR during the first two inter‐set recoveries (Δ = 16.04 and 15.50 pp; p ≤ 0.05), whereas this difference reversed during the non‐occluded third recovery (Δ = −6.00; p = 0.010). Early SmO2 resaturation slopes (0–30 s) were slower with BFR in recoveries 1–2 (Δ = +0.250 and + 0.209 pp/s; p < 0.001 and < 0.05), but not recovery 3. Heart rate and breathing difficulty increased across sets, without condition effects. Response showed condition × set interactions, with higher leg discomfort (Set 2) and perceived exertion (Sets 2–3) under BFR. After exercise, countermovement height decreased in BFR (p < 0.001), not in sham‐BFR (p = 0.093). Inter‐set BFR increased peripheral physiological and perceptual stress and altered muscle oxygenation recovery without compromising repeated‐sprint mechanical performance or cardiovascular responses. This strategy may provide a practical method to enhance training stress in trained athletes, although greater post‐exercise reductions in jump performance suggest potential neuromuscular fatigue.
ABSTRACT This study investigated head acceleration event (HAE) probabilities between common contact‐drills in rugby league. Fifteen professional male academy players participated in three training sessions, completing standardised contact‐drills while wearing custom‐fitted iMGs, all sessions were filmed. HAE data (peak linear acceleration and peak angular acceleration) were captured, synchronised, and processed alongside video data. Binomial logistic regression and ordinal mixed‐effect regression models were used to calculate overall and exceedance probabilities. Data included 1402 (93 ± 50 per player) contact‐drill observations, of which 133 had HAEs ≥ 5 g (9 ± 8 per player). Substantial variability in probability for HAEs ≥ 5 g (1.3%–41.3%) was observed across drills. Standing wrestle had the highest HAE ≥ 5 g probability (41.3%; CI: 31.0%–52.3%), while tackle shield hits at 1 m had the lowest (1.3%; CI: 0.5%–3.4%). HAE probability was greater for tacklers than ball‐carriers. Overall, probability of a HAE ≥ 25 g was < 1.1%. Standardised contact‐drills varied in HAE probabilities, but chances of higher magnitude HAEs was low for all drills. Overall, the probability of a HAE during standardised contact‐drills was low, although practitioners should consider the differences (i.e., the variability) in HAE probabilities when managing HAE training exposure.
(A) Investigate test-retest reliability of posterior tibial pulse palpation to determine arterial occlusion pressure (AOP) and examine validity against hand-held Doppler ultrasound. (B) Investigate the suitability of using 130% systolic brachial blood pressure for prescribing cuff inflation pressure for blood flow restriction (BFR) exercise. Repeated measures, crossover design. Lower limb AOP was assessed in 20 adults ≥ 60 years using hand-held Doppler ultrasound and posterior tibial pulse palpation. Brachial systolic blood pressure (bSBP) was measured to predict cuff inflation pressures (bSBP130%). On three occasions > 24 hours apart, three AOP measurements were recorded by the same blinded rater to determine intra-rater reliability. Participants lay supine, with arterial occlusion achieved using a rapid inflation system and a 10-cm cuff. Reliability was assessed via intraclass correlation coefficients (ICC), coefficients of variation (CV) and Bland-Altman plots, with validity examined via Pearson's product-moment correlations and Bland-Altman plots. Good to excellent reliability was observed for AOP assessed with Doppler ultrasound (ICC = 0.91, CV = 5.4%) and palpation (ICC = 0.91, CV = 5.8%). A strong positive correlation was observed in AOP values between methods (r = 0.85-0.92, p < 0.001), though palpation significantly underestimated AOP compared to Doppler ultrasound (-11.8 mmHg ± 8.32; p < 0.001). bSBP130% was not different to 100% AOP determined with hand-held Doppler (p = 0.516). Palpation may provide a reliable and clinically acceptable alternative to hand-held Doppler ultrasound for assessing lower limb AOP for blood flow restriction exercise. Employing bSBP130% may result in complete arterial occlusion with a 10 cm cuff, which is not supported by current BFR exercise recommendations for sub-occlusive pressures.
ABSTRACT Sodium bicarbonate positively impacts performance, but its associated gastrointestinal symptoms (GIS) may limit use. This systematic review synthesized literature that has evaluated GIS with sodium bicarbonate supplementation. Literature searches were performed from February 2024‐March 2026. Eligible studies provided ≥ 5 g of sodium bicarbonate within a 24‐h period or, if a multi‐day protocol, at least one day involving ≥ 5 g. Included studies had a placebo group/condition or a comparison group/condition that created a contrast related to delivery method, form, or dose. In total, 101 investigations were summarized in six categories: acute single dosing (n = 35); acute spread dosing (n = 28); chronic dosing (n = 7); acute versus chronic dosing (n = 5); delivery form (n = 18); and other (n = 8). Existing literature suggests that common acute doses (0.2–0.4 g/kg) elicit mild‐to‐severe GIS, which likely increase in a dose‐dependent manner when sodium bicarbonate is ingested in a single dose. Strategies to reduce GIS with acute dosing include spreading intake over hours, using enteric‐coated capsules/tablets, and ingesting sodium bicarbonate mini‐tablets within a carbohydrate hydrogel. Direct comparisons of these strategies to reduce GIS are absent in current literature; thus, ranking their effectiveness is not possible. Multi‐day dosing may lessen GIS, but symptom documentation throughout supplementation periods is poorly characterized. Notably, 26 of 101 studies failed to perform inferential statistical testing to examine condition/group differences in GIS. Making definitive recommendations about sodium bicarbonate supplementation to minimize GIS remains challenging. Major needs remain for direct comparisons between protocols purported to reduce GIS and improvements in GIS data collection, reporting, and analysis.
ABSTRACT This study aimed to determine the mechanical and energetic responses to accentuated eccentric loading (AEL) during maximal countermovement jumps (CMJ) and examined potential mechanisms underlying performance enhancement relative to bodyweight CMJs. We hypothesized that increased lower limb forces during loading would enhance positive work output during push‐off. Fifteen recreationally active men with good jumping ability (22.3 ± 4.5 years, 1.85 ± 0.06 m, and 79.1 ± 9.6 kg) performed maximal CMJ with and without AEL using handheld dumbbells equivalent to 20% body mass. Compared with bodyweight CMJs, AEL CMJ increased (p < 0.05) effective jump height (d = 0.521), center‐of‐mass work (d = 0.405), mean vertical ground reaction force (d = 0.346), peak (d = 0.864) and mean (d = 0.647) center‐of‐mass velocity, and peak (d = 0.497) and mean (d = 0.541) center‐of‐mass power during the propulsive phase. Effective jump height increased by 2.1 cm with AEL (0.548 ± 0.046 m) compared with bodyweight CMJs (0.527 ± 0.036 m). However, total lower‐limb joint work during push‐off, squat depth, and most lower‐limb electromyography parameters did not differ between conditions. Right ankle peak power and work during push‐off were lower with AEL, indicating a reduced ankle contribution despite improved jump height. These results do not support the claim that AEL enhances lower‐limb work output. Instead, increased center‐of‐mass work may have originated from segments not included in the joint‐level analysis, such as the trunk and upper body. Our findings suggest the hypothesis that altered whole‐body coordination, rather than greater lower‐limb work, contributed to the performance enhancement.
The effects of exercise intensity on airway epithelial integrity markers and inflammatory responses remain unknown. Therefore, we investigated the effects of high- and moderate-intensity exercise on airway epithelial integrity markers (club cell protein 16 [CC16], surfactant protein D [SP-D], and the CC16/SP-D ratio), along with systemic inflammation assessed via high-sensitivity C-reactive protein [hs-CRP] in healthy young men. Twenty healthy young men were randomly divided into two groups: high-intensity (n = 10) and moderate-intensity (n = 10) and both groups completed 20-min of continuous intensity treadmill exercise. The exercise intensities for the high-intensity and moderate-intensity groups were 85%-90% and 65%-70% of maximum heart rate, respectively. Serum was collected before and at +1 and + 24 h after exercise. CC16, SP-D, and hs-CRP concentrations were measured using enzyme-linked immunosorbent assay. A two-way repeated measures analysis of variance suggested that CC16, SP-D, CC16/SP-D ratio, and hs-CRP changed significantly over time (p < 0.05). Time × group interaction effects were observed for CC16 (p = 0.032) and CC16/SP-D ratio (p = 0.010) but not for SP-D (p = 0.824) and hs-CRP (p = 0.422) concentrations. Post hoc analysis revealed that CC16 concentrations at +1 h (p = 0.002) and the CC16/SP-D ratio at +24 h (p = 0.005) were higher for the high- compared to the moderate-intensity group. Our findings suggest for the first time that exercise intensity has a significant impact on CC16 and the CC16/SP-D ratio but does not affect the release of SP-D or hs-CRP.
The aim of this study was to analyze the impact of an Anterior Cruciate Ligament (ACL) injury on movement variability (MV) and biomechanical variables in female basketball players during a drop vertical jump (DVJ) task, both with and without a ball. Female basketball players (n = 15) participated in this study. The participants performed two jump in each of six conditions (total = 12 jumps) in randomizer order: (i) Bilateral No Ball (2NB)-two-leg jump without a ball; (ii) Bilateral Ball (2B)-two-leg jump with a ball; (iii) ACL No Ball (ACLNB)-injured-leg jump without a ball; (iv) ACL Ball (ACLB)-injured-leg jump with a ball; (v) No ACL No Ball (NOACLNB) -uninjured-leg jump without a ball; (vi) No ACL Ball (NOACLB)-uninjured-leg jump with a ball. DVJ performance parameters were assessed using an accelerometer placed on the lower back and a force platform. MV was quantified using the multiscale entropy (MSE) derived from the acceleration data. The Complexity Index (CI) was also calculated. The ACLB condition exhibited the highest sample entropy (SampEn) value across all scales, followed by the 2B and NOACLB conditions, whereas ACLNB showed the lowest values. The CI also indicated significant variability across conditions. For linear biomechanical variables, significant differences were only observed in contact time (CT) between NOACLB and NOACLNB. The inclusion of a task constraint did not result in differences between ACL and NOACL groups in linear jumping performance metrics. However, nonlinear MV analyses, using MSE and CI, revealed condition differences.
ABSTRACT Physical exercise benefits both cognition and physical health in aging, but it remains unclear whether benefits derive mainly from intensity or task complexity. Continuous exercises involve repetitive and predictable movements (e.g., running), whereas serial exercises (e.g., dancing) integrate varied motor sequences, and are cognitively more demanding. Clarifying the contribution of intensity and complexity is crucial for designing physically safe yet cognitively stimulating programs, maximizing preventive and rehabilitative potential in older adults. The aim of the study was to compare the ability of continuous versus serial exercises to improve executive functions. Seventy‐two participants (mean age 66.8) were assigned to three groups: dance (DNC), endurance (END), and inactive controls (INA). Executive functions were assessed through the Flanker, Corsi‐Block, and Trail Making tests. Groups were compared with MANOVA, followed by ANOVAs and LSD post‐hoc. A group effect emerged in the Flanker task (p = 0.006). END showed faster overall response times (RT) than DNC (p = 0.002) and INA (p < 0.001); DNC and INA did not differ. Incongruent RT tended to be faster in END versus DNC (p = 0.068) and was faster versus IAC (p = 0.003). For congruent RT, DNC and END outperformed IAC (p = 0.002; p = 0.001). Conflict cost was lower in DNC versus INA (p = 0.041) and END (p = 0.043), with no INA versus END difference. Continuous exercise enhanced general processing speed, whereas serial exercise appeared more effective for cognitive flexibility and selective attention. These findings support prior evidence to guide future large‐scale interventions aimed at optimizing exercise‐based cognitive training for older adults.
ABSTRACT Motor competence (MC) is essential for an active lifestyle, enabling confident and effective participation in physical activities. Emerging evidence suggests that MC may also benefit young people's mental health. Therefore, this review aimed to synthesize evidence on the association between MC and mental health in youth. We conducted a systematic search of five databases: APA PsycINFO, CINAHL Complete, PubMed, Scopus and SPORTDiscus. Eligible studies were peer‐reviewed, published in English after 2014, and included healthy youth aged 5–19 years. Studies were required to report a quantitative association between at least one aspect of MC and mental health. Screening, data extraction, and risk of bias assessment were performed independently by two researchers. Study quality was evaluated using NHLBI Quality Assessment Tool. We used a structural equation modeling approach for meta‐analysis, and publication bias was assessed using funnel plots and Egger's regression test. We identified 6049 records after removing duplicates. 17 studies met the inclusion criteria, of which two lacked the necessary statistics for meta‐analysis. Most studies were cross‐sectional (n = 14) and included children (n = 13). We observed a small but significant association between MC and mental health (effect size = 0.30, 95% confidence interval 0.20–0.40). Significant moderators included study design, age, type of MC assessment, risk of bias, domains of MC and mental health. Our findings suggest that MC was associated with mental health in youth. Participants' age, domains of MC and mental health emerged as the most relevant moderators. Further experimental studies, particularly in adolescents, are needed to investigate underlying mechanisms. Trial Registration PROSPERO: CRD42024495894
We validated a wearable accelerometer and running watch for estimating peak vertical ground reaction force (vGRF) and cumulative weighted damage (CWD). First, 18 well-trained runners of equal sex distribution (3.3 ± 0.3 m/s habitual training pace) ran a range of speeds (2.7-4.0 m/s, plus training pace) on an instrumented treadmill as reference standard vGRF and wearable data were collected. Wearable data were inputted into a published equation to estimate peak vGRF. The wearable and equation systematically underestimated peak vGRF compared with the instrumented treadmill (mean bias: -0.22 BWs with LOA: -0.44 to 0.01; 9.4-10.1%RMSE). A linear regression model was used to derive a corrected equation to improve the estimate of peak vGRF. In the validation stage, the wearable and corrected equation were validated in 10 runners in an independent sample of equal sex distribution (3.2 ± 0.3 m/s habitual training pace) yielding excellent relationships and trivial errors for peak vGRF versus the reference standard (ICC3,1 = 0.87-0.97; p < 0.001; mean bias -0.008 BWs with LOA: -0.15 to 0.14 BWs; 1.5%-4.0% RMSE). To illustrate how these methods can be applied to runners at risk for a bone stress injury, CWD per km was estimated, resulting in trivial errors by the wearable versus the instrumented treadmill (ICC3,1 = 0.85-0.97; p < 0.001; 1.5-4.1%RMSE). In summary, a commercial wearable and corrected equation were valid estimates of peak vGRF and CWD. These methods have potential for monitoring training loads in runners at risk for bone stress injuries. An online calculator is provided to estimate peak vGRF and CWD from the running watch and wearable.
This study investigated ankle, knee, and hip joint movement coordination during brace use via a lower-limb kinematic chain approach, which may influence biomechanical factors associated with injury risk. Twenty badminton players performed a left forecourt kick lunge under four brace conditions. Kinematic and kinetic data were collected using a motion capture system (Qualisys Arqus A12, 200 Hz) and force plates (Kistler 569×, 1000 Hz). A one-way repeated-measures ANOVA was applied for statistical analysis. At initial contact, elastic ankle brace use reduced ankle inversion angle (p = 0.001) and knee varus angle (p = 0.010) compared to the no-brace condition. The use of a sleeve-type knee brace increased knee varus angle (p = 0.041) and knee varus moments (p < 0.001), while decreasing hip eversion moments (p = 0.006). Combined ankle and knee bracing increased knee varus angle (p = 0.009). The use of elastic ankle and sleeve-type knee braces was associated with condition-dependent changes in stability and inter-joint coordination due to the kinetic chain linking the hip, knee, and ankle. Protecting one joint may reflect compensatory adjustments in adjacent joints, which may have implications for brace selection. These findings should be interpreted cautiously in relation to injury prevention.
ABSTRACT Individual strength qualities have been associated with sprint performance, but previous researchers have not partitioned the unique and shared variance each contributes, nor included the full range of strength qualities in a single analysis. This study is the first to model all five strength qualities (heavy dynamic, fast dynamic, reactive, isometric, and explosive) concurrently against sprint performance. Multiple regression was used to quantify the unique and shared variance each quality contributes across multiple sprint distances. Eighty‐four resistance‐trained individuals (62 male, 22 female; 21.4 ± 3.4 years, 79.9 ± 12.1 kg), completed countermovement jumps, drop jumps, isometric squat, isometric mid‐thigh pull, and a three‐repetition maximum (3RM) back squat, alongside a 40‐m sprint. Three multiple linear regression models were constructed to partition the unique and shared variance contributed by each strength quality to sprint performance across 5–40 m and maximal velocity, with sex included as a covariate. Combining countermovement jump height, 3RM back squat, and drop jump reactive strength index explained up to 75.2% of variance in sprint performance. The addition of isometric peak force or force at 100 milliseconds resulted in negligible increases in explained variance.
This study evaluated the feasibility, acceptability and perceptual outcomes of a 7-week High-Intensity Multimodal Training (HIMT) intervention and an active matched control (Inter-Session Concurrent Training [ISCT]) in recreationally active adults across three community sites. This study highlights challenges of conducting experimental research in applied settings in collaboration with industry partners and provides recommendations for HIMT research and practice. This study used a mixed-methods convergent design to evaluate a two-arm parallel randomised controlled trial in recreationally active adults. The HIMT group completed 4 × 45-min sessions/week combining aerobic and resistance exercise in a circuit format. The ISCT group completed 2 × 45-min resistance circuit sessions/week and 2 × 45-min aerobic circuit sessions/week. Data were collected at baseline (Week 0), post-intervention (Week 7), and 4 weeks follow-up (Week 11) across three trial sites between June 2024 and November 2024. 80 participants (49 females, 31 males) completed baseline testing (138% of target). One participant withdrew post-baseline, with 79 randomised to HIMT (n = 41) or ISCT (n = 38). Post-testing was completed by 75 participants and follow-up by 73 participants. Session attendance was 91.4%, with participants completing 3.52 ± 0.52 sessions/week. Mean session rating of perceived exertion was 7.47 ± 1.40 (CR-10). The programme was perceived as tolerable and enjoyable. HIMT and ISCT for recreationally active adults within community-based settings is feasible and acceptable. Exercise professionals may consider using HIMT and ISCT to engage recreationally active adults in structured exercise, promoting preventative health and positive lifestyle behaviours. TRIAL REGISTRATION: This Randomised Controlled Trial was pre-registered with the Australian and New Zealand Clinical Trial Registry: ACTRN12624000556549, Protocol: https://osf.io/mxy93/, ETH24-9364.
ABSTRACT To evaluate whether strength training during chemotherapy alters (1) serum cytokines and (2) skeletal muscle autophagy‐ and heat‐shock‐related proteins in women with breast cancer. Exploratory analyses assessed associations between changes in physiological outcomes (muscle strength, cardiorespiratory fitness, and capillary density) and biomarker responses, and among cytokine changes. Women with breast cancer were randomized to strength training (n = 23) or usual care (n = 17). The training group completed supervised strength training twice weekly during chemotherapy; usual care maintained habitual physical activity. Assessments were performed pre‐chemotherapy (T0) and post‐chemotherapy/intervention (T1). Serum cytokines (IFN‐γ, IL‐1RA, IL‐6, IL‐8, IL‐10, IL‐17, MCP‐1, TNF‐α) were quantified, and muscle biopsies were analyzed for autophagy‐ and heat‐shock‐related proteins. In the strength training group, mean ± SD IL‐6 increased from 1.21 ± 0.47 to 1.69 ± 0.71 pg/mL and IL‐17 from 1.24 ± 0.25 to 2.18 ± 0.87 pg/mL. IFN‐γ also increased in the training group (14.4 ± 8.6 to 28.8 ± 17.3 pg/mL), however, the group×time interaction was not statistically significant. In the usual care group, IL‐6 and IL‐17 decreased. No changes were observed in other cytokines or in autophagy‐ or heat‐shock‐related proteins. Exploratory analyses showed no associations between changes in strength and autophagy proteins, cardiorespiratory fitness and cytokines, or capillary density and cytokines. Strength training during chemotherapy did not alter selected skeletal muscle autophagy‐ or heat‐shock‐related proteins, despite group differences in IL‐6 and IL‐17 over time. The clinical and mechanistic significance of these cytokine shifts remains uncertain and should be evaluated in larger studies with additional time points and complementary immune and muscle outcomes.
ABSTRACT This study reports biceps femoris long head (BFlh) fascicle length and eccentric knee flexion strength changes following a 9‐week in‐season low‐volume resistance training intervention in elite under‐20‐year‐old (U20) male Gaelic footballers with and without previous hamstring injury. We included 26 male Gaelic footballers (age = 18.5 ± 0.5 years; height = 183.1 ± 5.1 cm; body mass = 79.2 ± 7.9 kg) in this study, with 10 of these participants reporting previous hamstring injuries within the last 12 months. Participants performed two sets of four Nordic hamstring exercise (NHE) repetitions and three sets of six staggered‐stance Romanian deadlift (RDL) repetitions once per week for nine weeks. Before and after the intervention, BFlh fascicle length was assessed via ultrasound and eccentric knee flexion strength was measured during the NHE. We ran separate linear mixed‐effects models for BFlh fascicle length and eccentric knee flexion strength, with fixed‐effects of time (baseline and follow‐up), limb‐type (previously injured and contralateral uninjured limbs of previously injured participants and between‐limb average of uninjured participants) and the time*limb‐type interaction. The linear mixed‐effects model for BFlh fascicle length revealed a significant main effect of time ( β = 0.31 cm; SE = 0.15 cm; p = 0.04), while the time*limb‐type interaction was not statistically significant. The linear mixed‐effects model for eccentric knee flexion strength revealed no significant increase in eccentric knee flexion strength ( β = 9.53 N, SE = 12.97 N, p = 0.47), while the time*limb‐type interaction was not statistically significant. These findings suggest changes to BFlh fascicle length and eccentric knee flexion strength from baseline to follow‐up were comparable across all limb‐types.
ABSTRACT Activities of daily living (ADL) are associated with declines in physical fitness and subjective health. However, it remains unclear as to whether ADL impairments are related to specific components of physical fitness and health variables. Therefore, we examined differences between community‐dwelling older persons with versus without ADL impairments with regard to various physical fitness components, physical complaints as well as subjective and objective health outcomes. Cross‐sectional study among 254 participants aged ≥ 55 years [51% female; 84 with ADL impairments; mean (SD) age 62.1 (6.6) years] enrolled in the population‐based “Gesundheit zum Mitmachen” study in Southwestern Germany. ADL, physical complaints and subjective health status were assessed using a self‐report questionnaire, physical fitness (cardiorespiratory fitness, strength, gross motor coordination, flexibility, and functional mobility) was assessed using a fitness test battery, and objective health status was derived from health exam performed by a physician. We ran analyses of covariance, adjusted for age, sex, body mass index and education. Participants with ADL impairments had statistically significantly worse subjective (p < 0.001) and objective (p < 0.001) health and reported more physical complaints (p < 0.001) compared to those without ADL impairments. Regarding physical fitness, ADL‐impaired participants performed worse in 10 out of 12 variables. The findings provide additional evidence that ADL impairments are related to decreased objective and subjective health and physical fitness in older community‐dwelling adults. Future studies employing more comprehensive, preferably objective, ADL assessments and considering cognitive impairments, which may also impact ADL performance, are warranted.
