Swimnews: Scientific Articles on Swimming
Current research listing presented by swimclinic.ch
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Thinking outside the box: comparing age at performance milestones of swimmers to cross-country skiers and biathletesKårström, M.J. et al.: J Sci Med Sport. 2026 Jul;29(8):897-902 doi: 10.1016/j.jsams.2026.01.014. Epub 2026 Jan 23.Objectives To compare age at key performance milestones between technical whole-body endurance sports and performance levels. Methods All top 30 swimmers, cross-country (XC) skiers and biathletes, who competed at the latest World championships (WC) were included and their ages at specific performance milestones (debut, first 17-30 rank, 9-16 rank, top 8) at junior (JWC) and adult WC were extracted from databases (719 women and 850 men). Athletes were divided into various performance levels based on their best individual ranking from adult competitions and compared using linear mixed model analysis. Results Only ~40% of the WC swimmers had competed in the JWC compared to ~90% of XC skiers and biathletes. Swimmers were, on average, 2 and 4 years younger at JWC and WC, respectively, than XC skiers and biathletes. In all three sports, there was an age gap (p < 0.05) between the highest junior performance milestone and adult WC debut (3-4 years) but no age difference (p > 0.05) between the performance milestones or performance levels at JWC. On average, female swimmers reached performance milestones one year earlier than their male counterparts, while there was no sex difference in XC skiing and biathlon. Conclusions The present findings encourage reassessment of sport-specific stereotypes regarding long-term athlete development. Although overall development patterns are similar between men and women, sex-specific training and competition planning is necessary at key junior career stages. Analyzing key structural elements of development systems across three technical whole-body endurance sports provides insights to develop future strategies for long-term athlete development. |
The effects of high-intensity interval training on competitive swimmers: A systematic review and meta-analysisRangxi J. et al.: J Sci Med Sport. 2026 Jul;29(8):911-922. doi: 10.1016/j.jsams.2026.02.015. Epub 2026 Feb 27.Objectives This systematic review and meta-analysis evaluated the effects of high-intensity interval training (HIIT) on physiological adaptations and performance in competitive swimmers. Methods Following PRISMA guidelines, five databases were searched from inception to July 2025. Eligible studies included randomized controlled trials and intervention studies examining HIIT in competitive swimmers. Methodological quality was assessed using PEDro scale. Random-effects meta-analyses calculated standardized mean differences (SMDs) with 95% confidence intervals. Results Eleven intervention studies comprising 237 competitive swimmers (mean age 15.4 ± 2.5 years) were included. HIIT significantly improved VO2max (SMD = 0.86, 95% CI: 0.52-1.20, p < 0.001, I2 = 0%) and swimming performance (SMD = 0.52, 95% CI: 0.36-0.68, p < 0.001). Sprint events showed greatest improvements (1.8%). Polarized training produced superior VO2max gains (8.8%) compared to traditional sprint interval training (6.6%) and threshold training (4.7%). Interventions ≥8 weeks yielded larger effects (SMD = 0.78) than shorter protocols (<8 weeks) (SMD = 0.42). Ultra-short race-pace training maintained 98.5% of target velocity with 24% lower lactate and 14% lower perceived exertion compared to traditional methods. Conclusions HIIT produces consistent improvements in aerobic capacity and swimming performance in competitive swimmers. For sprint events (50-100 m), ultra-short race-pace training is recommended; for middle-distance (200-400 m), polarized training; for distance events (≥800 m), preliminary evidence suggests that pyramidal approaches may be beneficial, though further research is needed. Minimum 8-week interventions are required for meaningful adaptations. |
Caffeine makes a splash: a systematic review and multilevel meta-analysis exploring the effects of caffeine intake on swimming performanceWang, Z. et al.: J Int Soc Sports Nutr. 2026 Dec 31;23(1):2692016. doi: 10.1080/15502783.2026.2692016. Epub 2026 Jun 21.Background Evidence for acute caffeine supplementation in swimming remains inconsistent across reviews, likely due to between-study heterogeneity and methodological differences. Methods Five databases were searched for randomized placebo-controlled crossover trials exploring the effects of caffeine on swimming performance in competitive swimmers. Performance outcomes were pooled as standardized mean differences (SMD; Hedges' g), with time outcomes sign-reversed so that positive values indicated improved performance. Dependence among multiple outcomes within studies was addressed using three-level random-effects models (REML). As a supplementary, interpretable metric, log ratios of means (lnRoM) were meta-analysed and expressed as percentage change. Post-exercise blood lactate (mmol/L) was pooled as mean differences (MD). Risk of bias was assessed using RoB 2 and certainty of evidence using GRADE. Prespecified exploratory moderator analyses examined potential effect modification (dose, timing, distance, administration form, stroke, gender, and athlete level). Results Thirteen studies were included (144 men and 48 women), which contributed 28 performance effect sizes. Caffeine improved swimming performance (SMD = 0.57, 95% CI: 0.20 to 0.94; p = 0.005), corresponding to a +1.71% improvement in lnRoM (95% CI: +1.01% to +2.41%; p < 0.001). Heterogeneity was substantial (I²total = 64.7%) and primarily between studies. Eight studies contributed 24 blood lactate effect sizes. In the meta-analysis, caffeine increased post-test lactate (MD = 0.85 mmol/L, 95% CI: 0.22 to 1.49; p = 0.016) with high heterogeneity (I²total = 76.5%). Exploratory moderator analyses suggested a possible dose-related pattern for swimming performance, with larger pooled effects at ≥6 mg/kg (SMD = 0.95, 95% CI: 0.52 to 1.38) than at <6 mg/kg (SMD = 0.22, 95% CI: -0.15 to 0.60; p difference = 0.017). Other performance moderators did not show clear between-subgroup differences. For lactate, exploratory subgroup analyses suggested larger increases in freestyle and short-distance events, although these patterns were more sensitive to modelling assumptions and should be interpreted cautiously. Conclusions Acute caffeine ingestion confers a moderate ergogenic benefit for swimming performance (SMD = 0.57, 1.7% improvement) and is associated with higher post-test blood lactate (MD = 0.85 mmol/L). Dose (≥6 mg/kg) may be associated with larger performance benefits, whereas lactate responses appear more pronounced in freestyle and shorter events. However, these subgroup findings are hypothesis-generating and require exploration. |
Creatine Supplementation in Endurance and Mixed-Sport Contexts: A Scoping Review of Performance, Recovery, and Body CompositionWesołowski, I. et al.: Nutrients. 2026 May 24;18(11):1677. doi: 10.3390/nu18111677.Background/Objectives Although creatine monohydrate is widely recognized as an effective ergogenic aid in strength and power sports, its role in endurance and mixed-sport disciplines remains less clearly established. This scoping review aimed to map the current evidence regarding the effects of creatine supplementation on performance, recovery-related outcomes, and body composition in endurance and mixed-sport contexts. Methods A scoping review of randomized controlled trials published between 1996 and 2025 was conducted. Eligible studies evaluated creatine supplementation in endurance and mixed-sport contexts, including both sport-specific and broader exercise populations when the exercise protocol, testing model, or outcomes were relevant to endurance or mixed-sport performance, recovery, or body composition. A total of 38 studies met the inclusion criteria. Outcomes were categorized into exercise performance, biochemical markers related to recovery and exercise stress, and body composition parameters. Results Creatine supplementation was most often associated with reported favorable changes in repeated-sprint performance and high-intensity power output, particularly during intermittent, sprint-based, or power-endurance tasks. Several studies reported favorable changes in sprint performance, peak power, or total work output relative to placebo or baseline values in cycling, swimming, rowing, and canoeing/kayaking protocols, although findings were not uniform across studies and not all favorable within-group changes were placebo-superior. Some studies also reported favorable changes in end-phase sprint capacity during prolonged exercise. Findings related to recovery were less consistent. Selected studies reported reductions in inflammatory markers, including C-reactive protein (CRP) and tumor necrosis factor α (TNF-α), whereas markers of muscle damage showed mixed responses. Most supplementation protocols involved a 5-7-day loading phase of 20 g/day, occasionally followed by a maintenance dose of 2-5 g/day. Small increases in total body mass were commonly observed, while evidence regarding fat-free mass and aerobic outcomes remained limited or inconsistent. Conclusions Current evidence suggests that creatine supplementation may be most relevant in selected endurance and mixed-sport contexts involving repeated high-intensity efforts, sprint finishes, or power-endurance demands, rather than for endurance performance broadly. In contrast, evidence for recovery-related biochemical responses, body composition changes, and aerobic adaptations remains equivocal. Further well-controlled, sport- or context-specific, and field-based studies are needed to better clarify the role of creatine in endurance and mixed-sport exercise. |
Swimming turns reduce energy demands of the aerobic performance in front crawlBosetto, P. et al.: Eur J Appl Physiol. 2026 May;126(5):2491-2500. doi: 10.1007/s00421-025-06084-7. Epub 2025 Dec 6.Purpose Performances in short-course (SC, 25 m) are typically faster than in long-course (LC, 50 m), largely due to the greater number of turns, but the specific energetic contribution of turns has not yet been quantified. This study tested the hypothesis that turns reduce the overall energy cost (C) in swimming, providing an energetic advantage in SC over LC. Methods Eleven male swimmers completed two randomized sessions in SC and LC pools, each consisting of five 400-m front crawl trials at submaximal intensity (70-86% of race velocity) paced by an underwater light system. Turn and clean swimming velocities were standardized between conditions to isolate the effect of turn number. Oxygen uptake, blood lactate, heart rate, perceived exertion, and stroke frequency were assessed, and metabolic power, total energy expenditure (Etot), and C (Etot/distance) were calculated. Results When analyzed at equivalent intensity (e.g. in trials corresponding to the same % of race velocity) mean velocity was higher in SC than LC across all intensities (+ 0.07 ± 0.003 m·s⁻¹, + 5.2%) while kinematic, physiological, and energetic parameters showed no significant differences (p > 0.05). When analyzed at paired (absolute) speeds, C values were about 4% higher il LC than in SC, indicating that swimming in short course is more economical, as hypothesized. Conclusions Turns reduce the overall energy cost of 400-m front crawl performance enabling swimmers to sustain higher mean velocities in SC. This highlights the importance of considering pool length when evaluating performance and prescribing training intensities. |
Swimming-Related InjuriesVerheul, D.: Clin Sports Med. 2026 Jul;45(3):507-519. doi: 10.1016/j.csm.2025.09.004.Abstract Swimming is a popular sport at both domestic and international levels. Over the last 40 to 50 years, there has been an increased focus on swimming injuries and the risk factors associated with them. While the bulk of the work has been done identifying and classifying injuries of the shoulder, given the whole-body nature of the sport, numerous other sites have been reported. Fortunately, the majority of these are overuse in nature, and the need for surgical management remains relatively low. |
Impact of an Overload Period on Heart Rate Variability, Sleep Quality, Motivation, and Performance in High-level Swimmers: Use of Explainable Artificial Intelligence (XAI) to Assess Training Load VariationsCarvalho, D. et al.: Sports Med. 2026 May;56(5):1235-1254. doi: 10.1007/s40279-025-02369-1. Epub 2025 Dec 5.Background Understanding the impact of training sessions on physiological, psychological, and immunological responses is crucial for adequate training periodization and preventing negative influences on health, training, and performance. Objectives: To characterize the responses of heart rate variability (HRV), sleep time and quality, motivation, dry-land strength, and swimming performance to an overload period of three consecutive 7-day cycles (cycles 1, 2, and 3) with different training intensity and volume dynamics. Secondly, to test the capability of HRV to assess daily variation in training loads on the basis of explainable artificial intelligence (XAI) models. Methods A total of 14 high-level swimmers (4 males and 10 females, aged 17.5 ± 1.5 years) were monitored via an orthostatic test, Hooper index, sleep questionnaires, and rating of perceived exertion (RPE) of each training session. The self-reported and prescribed training loads were compared. At the beginning of each cycle and at the end of cycle 3, swimmers completed anthropometric testing, countermovement jumps, hand-grip strength tests, and a 5 × 200 m incremental protocol. Results High-level swimmers accurately perceived their daily training loads. However, differences between the training and RPE loads emerged on weekends, indicating that physiological and psychological loads have different influences and should be considered simultaneously when characterizing training loads. The overload period was characterized by an increase in both training (27%) and RPE (20%) loads without eliciting a negative effect on sleep quantity and quality. During the overload period, supine (F2.18 = 3.448, η2 = 0.28; p = 0.05) and standing (F2.18 = 3.809, η2 = 0.30; p = 0.04) mean heart rate (HR) increased and supine log root mean square of the successive differences (LnRMSSD; F2.18 = 4.379, η2 = 0.33; p = 0.028) and maximal blood lactate (F3.27 = 3.441, η2 = 0.28; p = 0.03) decreased during and after cycle 3 (respectively). Dry-land and swimming performances were maintained, indicating that the autonomic nervous system appears to be more sensitive (XAI models r2 = 0.91 and 0.9) to changes in acute/short-term training load. Conclusions HRV indices, particularly supine RMSSD and mean HR, were the most sensitive markers of training load variation, while sleep, strength and power, and swimming performance remained stable. HRV can be employed as a practical tool for monitoring training responses and managing training loads in competitive swimmers. |
Swimmer’s Shoulder: An Update on Pathogenesis, Risk Factors, Clinical Assessment, and ManagementEdenfield, K.M. et al.: Curr Phys Med Rehabil Rep 13, 35 (2025). https://doi.org/10.1007/s40141-025-00506-5Purpose of Review Shoulder pain is the most common cause of pain in competitive swimmers. This review will cover the current available literature on the pathogenesis, assessment, management, and gaps in knowledge of swimmer’s shoulder; and provide insight into the practical clinical evaluation, treatment, and future directions from a multi-disciplinary group of authors with extensive clinical experience treating swimmers. Recent Findings Good thoracic mobility and extension is vitally important in the scapula’s success maintaining dynamic stability of the glenohumeral joint in swimmers. Both the front squat and overhead squat are good functional movement assessments for shoulder mobility and stability. Three evidence-based risk factors for shoulder pain in swimmers have been identified by experts and supported with evidence in the literature: low posterior shoulder strength-endurance, inconsistent training load, and poor stroke technique. Additionally, twenty-two other risk factors have been proposed by swimming experts, though these have not been investigated adequately in the literature. Summary Overdevelopment of the anterior shoulder muscles combined with tightness in the pectoralis minor and posterior shoulder capsule, imbalanced scapular stabilizers, and decreased thoracic mobility can lead to fatigue, dysfunctional swim stroke, and shoulder pain. Evaluation should focus on known risk factors and utilize functional movements. Treatment should be interdisciplinary and include relative rest, anti-inflammatories, stretches of the posterior capsule and pectoralis minor, and a progressive exercise program of shoulder and scapular strengthening. |
Swimming is superior to running in inducing physiological cardiac hypertrophy and enhancing myocardial performanceYoshizaki, A. et al.: Sci Rep 16, 6592 (2026). https://doi.org/10.1038/s41598-026-36818-2Abstract Aerobic exercise training (AET) can induce cardiac hypertrophy, but the specific adaptive response for different types of AET remains unclear. We evaluated nonsingular cardiac remodeling in rats through running (RT) and swimming (ST) training at approximately 75% of VO₂max. Male Wistar rats (8–10 weeks old; ~ 250 g) were divided into untrained (UT), RT, and ST groups. The RT and ST were performed five days a week, once daily for 60 min for eight weeks. Cardiopulmonary fitness was assessed by measuring maximal oxygen consumption and swimming time to exhaustion. Echocardiography evaluated left ventricular parameters, while myocardial mechanics were assessed through the papillary muscle. Histology and Western blotting were performed to evaluate cardiomyocyte size and proteins modulating phosphoinositide 3-kinase (PI3K110α)/AKT1 signaling. Real-time PCR was used to assess the expression of genes and microRNAs involved in myocardial hypertrophy. Both AET protocols enhanced cardiopulmonary capacity, but only the ST group showed increased myocardial mass, cardiomyocyte growth, and LV cavity size, along with greater tension and papillary muscle shortening velocity. A more pronounced alteration in gene expression pattern for proteins modulating PI3K110α/AKT1 signaling was found in the ST group than in the RT group. A similar difference was also found for microRNA 1, 21, 27a, 124, and 144 expressions. ST is more effective than RT in inducing cardiac hypertrophy and enhancing contractility, linked to the PTEN-AKT-S6K1 pathway and increased expressions of microRNAs 1, 21, 27a, 124, and 144. Thus, ST is superior to RT for inducing physiological cardiac hypertrophy. |